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HCUP Overview Course - Accessible Version

HCUP Overview Course - Accessible Version


Welcome

Researcher 1: Do admission rates for preventable hospitalizations vary across the U.S.?

Researcher 2: What percentage of hospitalizations for children are uninsured in my state?

Researcher 3: What are the most common conditions treated in the Emergency Department?

Researcher 4: Will there be enough cases for my analysis?

Researcher 5: What are the latest trends in ambulatory surgery for knee injuries?

Researcher 6: What tools are available to help me in my research?

 

Lauren: HCUP. Powerful Data. Meaningful answers.

 

Contents:

 

Introduction

Sean: Welcome to the Healthcare Cost and Utilization Project Overview Course. My name is Sean. I am a researcher who is studying a number of different health care research and policy topics. My current research interests include looking at the rise in the number of obesity-related procedures in recent years. I'm not overly familiar with HCUP. I've heard that it's a valuable resource. I've accessed publications and resources available through HCUP, and I'd like to learn about using HCUP databases and tools to support my research. My colleague, Lauren, has worked with HCUP products for years.

Lauren: Yes, hi, I'm Lauren. Sean, you're right, I've had significant exposure to HCUP and am happy to give you an overview of the databases, software tools, and research products included in HCUP. During my research career, I've used HCUP to support various healthcare analyses. Most recently, I used HCUP to identify trends in preventable asthma hospitalizations. There is a wealth of information available through HCUP. Sean, I've put together a course on HCUP that I'll share with you and anyone else interested in learning about HCUP. During this course, I'll introduce you to the various HCUP databases and related products and help you determine if one or more of these resources can support your research interests. By the end of this course, you will:

  • Understand the HCUP databases, software tools, and products.
  • Know the features, capabilities, and potential uses of the HCUP resources and how to access them.
  • Know how to use HCUPnet – a free, online querying tool.
  • Know where to access additional information on the HCUP User Support Web site.

I estimate that this course will take about 90 minutes to complete and will be covering a lot of information about the HCUP project and databases. While the course is designed to present a comprehensive overview of HCUP, we understand that you may be interested in accessing only certain information.

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Introduction/AHRQ and DHHS

Lauren: The Healthcare Cost and Utilization Project or HCUP, is a family of health care databases and related software tools and products developed through a Federal-State-Industry partnership and sponsored by the Agency for Healthcare Research and Quality (AHRQ).

HCUP databases bring together the data collection efforts of State data organizations, hospital associations, and private data organizations to create a national information resource of record-level health care data.

HCUP data are collected as part of AHRQ's mission: "To produce evidence to make health care safer, higher quality, more accessible, equitable, and affordable, and to work with HHS and other partners to make sure that the evidence is understood and used."

AHRQ is a federal agency in the Department of Health and Human Services (DHHS). The Department of Health and Human Services is the principal department for improving the health of all Americans and providing essential human services, especially for those who are least able to help themselves.

There are many agencies within DHHS. A few examples are the National Institutes of Health (NIH), the Centers for Medicare and Medicaid Services (CMS), the Food and Drug Administration (FDA), and the Centers for Disease Control and Prevention (CDC).

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Introduction/What is HCUP?

Lauren: HCUP provides a wealth of information to enhance your research and promote positive changes in healthcare. HCUP is a family of healthcare databases, software tools, and products that support cutting edge research. The HCUP databases include discharges for inpatient care and components of outpatient care, such as emergency care and ambulatory surgeries. These data are collected from community hospitals in participating states.

HCUP consists of a family of related databases, tools, and products.
HCUP is more than simply a set of hospital databases. HCUP also creates many software tools and a variety of reports. For more information, visit the HCUP-US Web site.

HCUP supports cutting edge research.
HCUP data support cutting-edge health services research and policy development. HCUP data-supported studies are published in:

  • The New England Journal of Medicine (NEJM)
  • The Journal of the American Medical Association (JAMA)
  • Pediatrics
  • Medical Care
  • Health Affairs
  • Journal of Health Economics
  • Popular magazines, such as Newsweek

HCUP also supports Congressionally-mandated reports, such as the National Healthcare Quality and Disparities Report (QDR).

HCUP captures all discharges for inpatient care and certain components of outpatient care from community hospitals in participating states. HCUP data capture all inpatient discharges from community hospitals in participating states, as well as components of outpatient care (e.g., emergency care and ambulatory surgeries and services). Also, the HCUP state-level databases capture all discharges, making them unique and powerful. These databases are the only collection of publicly available, all-payer hospital data.

Introduction/Overview of HCUP Data

At the center of the HCUP project are the data. HCUP data are derived from hospital billing information and include both inpatient and outpatient care.

HCUP Inpatient Databases:

  • The State Inpatient Databases (SID) are a set of state-level databases that capture discharge-level* inpatient data in participating states. Researchers and policymakers can use the SID to study many state-level issues surrounding health care utilization, access, charges and costs, quality, and outcomes. *The term discharge is reserved to describe a record for a patient who has been admitted to the hospital for inpatient care and subsequently discharged. HCUP uses the term encounter to describe a record that only includes information on outpatient services.
  • The National Inpatient Sample (NIS) is a national database of hospital inpatient stays derived from the SID. Researchers and policymakers use the NIS to identify, track and analyze national trends in health care utilization, access, charges and costs, quality, and outcomes.
  • The Kids' Inpatient Database (KID) is a national database of hospital inpatient stays for children. The KID is derived from the SID and is specifically designed to permit researchers to study a broad range of conditions and procedures related to child health issues.
  • The Nationwide Readmissions Database (NRD) is a national database of hospital inpatient stays derived from SID with verified patient linkage numbers. The NRD is designed to permit researchers to estimate national rates of readmission for all payers and the uninsured, in addition to explore reasons for returning to the hospital for care, and the hospital costs for discharges with and without readmissions.

HCUP Outpatient Databases:

  • The State Ambulatory Surgery and Services Databases (SASD) are a set of state-level databases that capture encounter-level* data for ambulatory surgery and other outpatient services from hospital-owned facilities. In addition, some States provide ambulatory surgery and outpatient services from non-hospital-owned facilities. The SASD are well suited for research that requires complete enumeration of ambulatory surgery in hospital-owned facilities within market areas or States. Researchers and policymakers can use the SASD to study many topics related to outpatient surgeries. *The term discharge is reserved to describe a record for a patient who has been admitted to the hospital for inpatient care and subsequently discharged. HCUP uses the term encounter to describe a record that only includes information on outpatient services.
  • The State Emergency Department Databases (SEDD) are a set of state-level databases that capture encounter-level* information for all emergency department visits that do not result in an admission to that hospital (e.g., treated and released, transferred to another hospital, died). Researchers and policymakers can use the SEDD to study many health care topics surrounding emergency department visits. *The term discharge is reserved to describe a record for a patient who has been admitted to the hospital for inpatient care and subsequently discharged. HCUP uses the term encounter to describe a record that only includes information on outpatient services.
  • The Nationwide Emergency Department Sample (NEDS) is a national database of emergency department visits derived from the SEDD and the SID. Researchers and policymakers use the NEDS to analyze emergency department utilization patterns and support decision-making regarding source of care.

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Introduction/Data Sources: Community Hospitals

I understand that HCUP data are largely hospital and hospital affiliated data, but what types of hospitals are included? What types of hospital care are captured and how do hospitals collect all these data?

The American Hospital Association (AHA) categorizes hospitals into five main categories, including:

  • Community
  • Federal
  • Long-term care
  • Psychiatric
  • Tuberculosis

The data in the HCUP databases primarily include data from non-federal community hospitals. Federal, long-term care, psychiatric, and tuberculosis hospitals are generally excluded. As you can see, the majority of hospitals in the United States are categorized as "community hospitals."

Examples of non-Federal community hospitals include (88%):

  • General multi-specialty community
  • OB-GYN
  • ENT
  • Orthopedic
  • Pediatric
  • Public
  • Academic medical centers

The following hospitals are generally excluded (12%):

  • Long-term care
  • Psychiatric
  • Alcoholism/chemical dependency
  • Rehabilitation
  • Hospital units of other institutions, such as prisons
  • Federal hospitals (Veteran's Administration, Department of Defense, Indian Health Service)

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Introduction/Data Sources: Types of Care Captured

Lauren: Generally, the care provided at community hospitals can be divided into three main categories: inpatient; outpatient; and ancillary services (such as pharmacy, laboratory, and radiology).

HCUP data capture records of inpatient care services and two types of outpatient care services - ambulatory surgery and emergency department. HCUP does not collect Ancillary Services such as laboratory or radiology services.

Inpatient
Inpatient care is included in the following databases:

  • State Inpatient Databases (SID)
  • National Inpatient Sample (NIS)
  • Kids' Inpatient Database (KID)
  • Nationwide Readmissions Database (NRD)

Outpatient
Outpatient care is included in the following databases:

  • State Ambulatory Surgery and Services Databases (SASD)
  • State Emergency Department Databases (SEDD)
  • Nationwide Emergency Department Sample (NEDS)

Ancillary Services
Pharmacy, laboratory, and radiology information is not typically captured in the HCUP databases, although a limited amount is represented if an ICD-9-CM or ICD-10-CM code exists. The SASD in some states include information on lithotripsy, radiation therapy, and imaging.

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Introduction/Data Sources: Billing Records

Sean: Interesting. So where does it originate and how does it get created?

Lauren: That's a good question, and the easiest way to find out is to follow some patients through the process. Let's take a look at three examples to see when data are collected.

Jeff is admitted to the hospital for pneumonia. After he is admitted, a medical record is created containing his demographic data. Because Jeff was admitted to the hospital, his treatment will be captured in the SID.

Jack arrives at a hospital-based surgery center for outpatient eye surgery. A medical record is created with Jack's demographic information. Because Jack is being treated and released in an outpatient setting of the hospital for a surgical procedure, his surgery will be included in the SASD.

Lizzie arrives at the emergency room with her mom after falling at the playground. A medical record is created with Lizzie's demographic information. If Lizzie is admitted to the hospital because of her fall, her care will be included in the SID. If she is not admitted, her care will be captured in the SEDD.

These three patients will receive care and information about that care will be added to their medical records. When each patient is discharged, a bill will be generated and the information included on that bill will become the basis of the HCUP databases. Read about the details of each step below.

Receive Care
Jeff, Jack, and Lizzie receive care, and information of this care are included in each patient's medical record.

Discharge
After receiving care, each patient is discharged. On each medical record, a medical coder classifies the care provided in diagnosis and/or procedure codes (ICD-9-CM, ICD-10-CM/PCS or CPT). A discharge summary is generated from each medical record for billing purposes. This discharge summary is the basis of HCUP data.

Bill Generated
The billing department uses the medical codes assigned by the coder to generate a hospital bill for each patient. Billing forms used by hospitals, such as the UB-92 form, include basic demographic data such as patient age and gender along with more detailed information such as the patient's diagnosis and what medical procedures were performed. Total hospital charges for patient care are also included.

Data Transmitted
Once a billing record (also called a discharge record) is generated, the hospital transmits the data to their State-level Data Organization.

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Introduction/Contributing States

Lauren: These data are used for many purposes other than billing. Hospitals transmit the data to state-level Data Organizations that utilize the information for things such as public health surveillance, research, and monitoring quality, cost and access to health care. The Data Organizations add additional data elements useful to researchers. The Data Organizations that participate in HCUP send their data to AHRQ for inclusion in the HCUP databases. We call the participating states "HCUP Partners." Along with AHRQ, they put a tremendous amount of effort into creating the HCUP databases. Without their support and enthusiasm for this project, the HCUP initiative would not be possible.

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Introduction/Comparison to Other Available Databases

Sean: I've used other federal databases such as the National Hospital Care Survey, the Medical Expenditure Panel Survey, and the Medicare Provider Analysis and Review in my research before. How are HCUP databases different from these?

Lauren: All of these databases are invaluable in conducting meaningful health services research, but specific databases may be more suited for certain types of analyses. Read below to find out how these databases compare to the HCUP databases.

The National Hospital Care Survey (NHCS)
National Hospital Care Survey describes national patterns of health care delivery in hospital-based settings, including inpatient departments, emergency departments, and outpatient departments, including hospital-based ambulatory surgery. Additionally, NHCS collects patient-level identifiers that allow a patient’s episodes of care to be linked between different hospital inpatient and outpatient settings, as well as to outside databases such as the National Death Index, providing a more complete picture of patient care.

HCUP data include inpatient and outpatient discharge records, also called administrative data - but HCUP data are not survey based.

The Medical Expenditure Panel Survey (MEPS)
Medicare Expenditure Panel Survey is a set of large-scale surveys of families and individuals, their medical providers, and employers across the United States. MEPS is the most complete source of data on the cost and use of health care and health insurance coverage. HCUP is not a survey – it is based on hospital discharge records.

The Medicare Provider Analysis and Review (MedPAR)
Medicare Provider Analysis and Review contains claims data for services provided to beneficiaries admitted to Medicare-certified inpatient hospitals and skilled nursing facilities. MedPAR data are limited to care for the Medicare population, while HCUP features all payers, including the uninsured.

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Introduction/Knowledge Check

Sean: Okay, I'd like to take a moment to review what HCUP data are and what they aren't before we proceed to learn about each of the HCUP databases.

Are these characteristics of HCUP databases? Answer yes or no for each statement listed below. There will be more than 1 right answer for this exercise.

  • Administrative billing data
  • Survey-based
  • Includes information on the uninsured
  • From non-Federal community hospitals
  • Includes both inpatient and outpatient care
  • Captures all or nearly all hospitalizations and visits
  • Includes physician office visits

Select this link for the answers to the Overview Knowledge Check: Answers to Overview Knowledge Check

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SID/What are the SID?

Lauren: At the center of HCUP's inpatient data are the State Inpatient Databases (SID).

The SID are a set of hospital databases that include inpatient hospitalizations in participating states. The SID include all or nearly all of the hospitalizations in each state by year, in other words, the databases are a "census" of hospitalizations by state. There is variation in database formats and definitions from state to state, but HCUP processes the data into a uniform set.

The National Inpatient Sample (NIS), the Kids' Inpatient Database (KID), and the Nationwide Readmissions Database (NRD), are derived from the SID. Data in the Nationwide Emergency Department Sample come from the SID and the SEDD.

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SID/Data Sources

Lauren: The SID are derived from hospital billing data. This type of data is also referred to as "administrative data.".

  • The SID include all or nearly all community hospitals in each participating state. All discharges from those community hospitals comprise the SID – there is no sampling of hospitals or discharges.
  • The SID include patient demographic information, such as gender, age, and for some states, race.
  • The SID include details of care, such as primary and secondary diagnoses, primary and secondary procedures, admission and discharge status, and length of stay. The SID also include total hospital charges and expected payment source.

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SID/Data Files and Elements

Sean: So, if I decided that I could use the SID in my research project, what would be included in the actual database itself?

Lauren: Each SID contains three types of data files: a core file containing common elements and state-specific variables, a charges file, and an AHA linkage file. The Core and Charges files are discharge-level files. The AHA Linkage file is a hospital-level file.

Core File: Core Data Elements

  • Form the nucleus of the SID.
  • Data elements common to all SID are derived from the hospital billing record and include:
    • Patient demographics
    • Diagnoses and procedures
    • Expected payer
    • Length of stay
    • Admission source and type
    • Admission month

Core File: State-specific Data Elements

  • Some states collect and provide data elements that are not available from other states, such as:
    • Race and ethnicity
    • Patient county and ZIP Code
    • Severity of illness
    • Primary payer details
    • Secondary payer
    • Physician specialty

Charges File

  • Contains the total charges submitted by the hospital for each discharge.
  • May contain different charge information details, depending on the state.
  • For some States, you may be able to identify details such as intensive care unit (ICU) patients and emergency department charges.
  • Contains information on charges, not the actual amounts reimbursed for each discharge.
  • Can be converted to costs using the AHRQ-developed HCUP Cost-to-Charge Ratio Files. More information about this topic is available later in the course.

American Hospital Association (AHA) Linkage File

  • Contains a small number of data elements that allow researchers to link hospital information on the SID to the AHA Annual Survey of Hospitals.
  • The AHA Annual Survey provides detailed hospital characteristics.
  • Not all SID include AHA linkage variables.
  • May not be used to identify specific hospitals in published reports.

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SID/Unique Attributes

Sean: My understanding is that AHRQ collects data from state-level data organizations to produce the SID files.

Lauren: The HCUP SID contain value-added data elements and pass standard data quality checks. Most important, the HCUP SID are uniformly coded. Uniform coding occurs across states, making state-to-state comparisons much easier.

Read more about the key differences below.

Have Value-Added Data Elements
During HCUP processing, AHRQ creates and includes many value-added data elements for research, such as rural-urban indicators.

Pass Standard Data Quality Checks
AHRQ conducts a limited number of standard data quality checks. For example, there are checks to ensure that the diagnosis codes (such as ICD-9-CM or ICD-10-CM codes) are complete. Another routine check is a "gender" check. For example, are hysterectomy procedures only coded for women? Are prostate surgeries coded exclusively for men?

Are Uniformly Coded Across States
Unlike the data files available directly from the states, the SID files are uniformly coded to make it easier for researchers to conduct state-by-state comparisons.

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SID/Availability and Pricing

Lauren: The SID are updated annually, and are released as they become available throughout the year.

Even though most States provide their inpatient data to the project, not all HCUP Partners make their data available to researchers for purchase. The online HCUP Central Distributor is the mechanism through which HCUP data can be purchased. The number of states allowing release of their SID through the online HCUP Central Distributor grows each year. Each state that participates sets its own price for the SID. The online HCUP Central Distributor handles these transactions as a service to the states—and payments for the SID are returned directly to each state.

For more information on the SID, see the SID Overview.

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SID/Research Topics

Lauren: The SID can support many types of health care services research.

  • The SID are well suited for research that requires complete enumeration of hospitals and discharges within market areas or states.
  • Researchers and policymakers use the SID to investigate questions unique to one state or to compare data from two or more states.
  • Researchers can identify state-specific trends in health care use, access, hospital charges and costs, and outcomes.
  • In certain states, the SID can be used to investigate race and ethnicity topics and hospital readmissions.

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SID/Knowledge Check

Sean: I feel like I have a good understanding of what's included in the SID now. Do you? Take a moment to identify what types of care would and would not be captured in the SID by answering the questions below.

Jane has a Cesarean section and remains in the hospital for two days. Would this record be included in the SID?

  • Yes
  • No

Madison receives routine vaccines and a check-up at her doctor's office. Would this be captured in the SID?

  • Yes
  • No

Mark is released after receiving outpatient treatment for a broken leg. Would this record be included in the SID?

  • Yes
  • No

Helen is admitted to a hospital with pneumonia. Would the record of her hospital treatment be included in the SID?

  • Yes
  • No

Select this link for the answers to the SID Knowledge Check: Answers to SID Knowledge Check

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SID/Summary

Sean: To summarize, the SID contain all of the inpatient discharge abstracts from community hospitals in participating states, translated into a uniform format to facilitate multi-state comparisons and analyses. Together the SID encompass about 97 percent of all U.S. community hospital discharges.

The SID contain a core set of clinical and nonclinical information on all patients, regardless of payer. This includes patients covered by Medicare, Medicaid, private insurance and uninsured individuals.

In addition to the core set of uniform data elements common to all SID, some include other elements, such as the patient's race.

Lauren: And you can find additional information on the HCUP User Support Web site.

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NIS/What is the NIS?

Sean: The SID sounds invaluable for investigating health issues or trends in a specific market or state, but I need national data for my research on current trends in obesity-related procedures.

Lauren: Don't worry. There is an HCUP database for you. HCUP creates the National Inpatient Sample (NIS) to make it possible for researchers to conduct national and regional analyses of hospital use and the hospital charges and costs associated with inpatient care.

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NIS/Sample Design

Lauren: The NIS is derived from the SID and approximates a 20% sample of discharges from all HCUP community hospitals in the U.S.

The SID
The SID include all or nearly all community hospitals in each participating state. These databases are considered a "census" of all hospital discharges (not a sample).

Sampling
The NIS consists of a stratified systematic sample of discharges from all hospitals in HCUP, equal to approximately 20% of all discharges in U.S. community hospitals.

Sampling Strata
Discharges are stratified in the NIS sample on the basis of five hospital characteristics (referred to as "strata" in HCUP). Stratification variables include:

  • Census Division - New England, Middle Atlantic, East North Central, West North Central, South Atlantic, East South Central, West South Central, Mountain, and Pacific
  • Location – urban or rural.
  • Teaching Status – teaching or non-teaching.
  • Control – government non-Federal (public), private not-for-profit (voluntary), or private investor owned (proprietary).
  • Bed Size – small, medium, or large.

Sample Size
The NIS contains a sample of over 7 million hospital discharge records taken from more than 4,000 HCUP participating hospitals, which is equal to approximately 20% of the total discharges from U.S. community hospitals for each data year. This large sample size allows researchers to study relatively rare diagnoses and procedures.

The NIS
The NIS is designed to be a national representation of hospital care. Because the NIS sampling frame is not designed with "state" as a stratification variable, state-level analyses cannot be conducted. If you are interested in analyses by state, obtain the state-specific SID.

Prior to the 2012 NIS

Lauren: Prior to the 2012 data year, the National Inpatient Sample was called the Nationwide Inpatient Sample. For the 2012 data year, the NIS was redesigned to improve national estimates. To highlight the design change, AHRQ renamed the "Nationwide" Inpatient Sample (NIS) to the "National" Inpatient Sample (NIS).

More information on the 212 NIS Redesign is available on the HCUP-US web site.

Beginning with the 2012 data year, the NIS contains a sample of discharge records from all hospitals participating in HCUP. Previous versions of the NIS contained all discharge records from a sample of hospitals participating in HCUP.

In order to allow more refined analyses of geographic variation in U.S. hospitalizations, the new NIS sampling design includes stratifiers for nine Census Divisions rather than four Census Regions that had been in the earlier NIS.

This new sampling strategy results in estimates with more precise statistical properties than the previous NIS design.

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Pre and Post 2012 NIS Redesign
  New NIS (beginning in 2012 Data Year) Previous NIS (1998-2011 Data Year)
Name National Inpatient Sample (NIS) Nationwide Inpatient Sample (NIS)
Universe Removed long-term acute care hospitals Included long-term acute care hospitals
Annual discharge estimates and hospital enitities based on information from the SID when available; otherwise based on AHA information Annual discharge estimates and hospital entities based on information from AHA
Strata Used hospital census division (9) for stratification Used hospital census region (4) for stratification
Sample Design 7 million hospital discharge records from more than 4,000 HCUP reporting hospitals 1,000 sampled hospitals amounting to more than 8 million records

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NIS/Comparison to the SID

Lauren: Let's take a closer look at the differences between the NIS and the SID.

All Discharges vs. Sample
The NIS is a sample of discharges while the SID includes all discharges from all or nearly all community hospitals in each state.

Data Elements
The NIS contains fewer data elements than the SID, but most of those variables are standardized. This NIS allows for national estimates.

Value-Added Variables: Severity Measures
There are several ways to adjust for severity of illness, and use of these methods can be costly and time-consuming. HCUP has therefore added severity measures to facilitate your research.

Severity Measures

There are several ways to adjust for severity of illness, and use of these methods can be costly and time-consuming. HCUP has therefore added severity measures to facilitate your research. The NIS includes two sets of severity measures:

  • All Patient Refined Diagnosis Related Groups (APR-DRGs), developed by 3M Health Information Systems.
  • Comorbidity measures, developed by AHRQ.
  • In previous years, two additional were used - All-Payer Severity-Adjusted Diagnosis Related Groups (APS-DRGs), developed by HSS, Inc., and Disease Staging, developed by Truven Health Analytics.

For further information, refer to the HCUP-US web site.

Hospital Characteristics
The NIS also contains several hospital characteristics derived from the AHA Annual Survey Database. These include:

  • Census Division
  • Urban/rural location
  • Teaching status
  • Ownership/control
  • Bed size category

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NIS/Availability and Pricing

Lauren: The NIS is one of the most popular HCUP databases and is released every year. It is an affordable database that is available through the online HCUP Central Distributor. For more information on the NIS, see the NIS Overview.

Price:

  • Beginning 2014: $500 per data-year
  • 2007 - 2013: $350 per data-year
  • 2000 - 2006: $200 per data-year
  • 1993 – 1999: $160 per data-year
  • 1988 – 1992: $322 for the entire set

Student Price:

  • Beginning 2013: $100 per data-year
  • 2007 - 2012:  $50 per data-year.
  • 1988 - 2006:  $20 per data-year.

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NIS/Research Topics

Lauren: The NIS can be used to examine many important aspects of health care services and health care policy, including the use of hospital services, charges and costs for these services, medical practice variation, medical treatment effectiveness, the quality of care and patient safety, the impact of health policy changes, the diffusion of medical technology, and disparities in the use of hospital services.

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NIS/Knowledge Check

Sean: The NIS seems like a good choice to study my research topic of interest, national trends in obesity-related procedures, but let's take a moment to identify whether the SID or the NIS would be better for some other research topics by answering the questions below.

Anna would like to identify differences in pneumonia hospitalizations in Maryland, as compared with Florida. Which database would Anna want to use?

  • SID
  • NIS

Linda would like to identify national trends in diabetes hospitalizations. Which database would Linda want to use?

  • SID
  • NIS

Tim would like to identify regional trends in hospitalizations for coronary artery bypass graft (CABG) procedures within the U.S. Which database would Tim want to use?

  • SID
  • NIS

Select this link for the answers to the NIS Knowledge Check: Answers to NIS Knowledge Check

NIS/Summary

Sean: Before we move on, let's review. The NIS is derived from the SID to allow researchers and policymakers to identify, track, and analyze national and regional trends in health care utilization, access, charges, quality, and outcomes.

The NIS's large sample size enables analyses of rare conditions, such as congenital anomalies; uncommon treatments, such as organ transplantation; and special patient populations, such as the uninsured.

The NIS is the only national hospital database with charge information on all patients, regardless of payer, including persons covered by Medicare, Medicaid, private insurance and uninsured individuals.

Prior to 2012, the NIS included hospital identifiers that permitted linkages to the American Hospital Association Annual Survey of Hospitals and county identifiers that permitted linkages to the Area Resource File. Beginning in the 2012 data year, this was not applicable.

Lauren: And as always, you can find this and more information about the NIS on the HCUP User Support Web site.

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KID/What is the KID?

Lauren: Much like the NIS, the Kids' Inpatient Database (KID) is derived from the SID. However, the purpose of the KID is to enhance research on inpatient stays for children and to enable researchers to make national estimates.

The KID is the only hospital administrative data set designed specifically to assess use of hospital services by newborns, children, and adolescents. It allows researchers to study specific conditions, procedures, and subpopulations that are sometimes difficult to analyze with other databases because children account for a relatively small proportion of hospital stays.

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KID/Sample Design

Sean: Since the KID is derived from the SID, I'd imagine the creation of it is similar to that of the NIS.

Lauren: For the most part it is, but there are a few differences.

Both the NIS and the KID are derived from the SID.

  • The NIS is a sample of discharges.
  • The KID is a sample of pediatric discharges.

KID Strata
Ten percent of uncomplicated in-hospital births and 80 percent of other pediatric cases from each stratum are sampled to create the KID.

The KID
The file structure is similar to the NIS, but with additional variables that are relevant for research on children (e.g., indicator of normal uncomplicated in-hospital birth).

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KID/Availability and Pricing

Lauren: Like the NIS, the KID is affordable and available through the online HCUP Central Distributor, so the purchasing process is straight forward. It is released every three years and pricing is shown below. Like the NIS, AHRQ offers a discounted price for students. For more information on the KID, see the KID Overview.

Please note: The KID is released every 3 years. However, since ICD-10 was introduced in October 2015, the KID release was deferred from data year 2015 to data year 2016.

Price:

  • Beginning data year 2009: $350 per data-year
  • Data years 1997-2006: $200 per year

Student Price:

  • Beginning data years 2009: $50 per data-year
  • Data years 1997-2006: $20 per data year

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KID/Research Topics and Examples

Lauren: There are numerous ways in which the KID can be used to support health services policy decisions and research. The KID enables studies on important topics such as the study of common and rare pediatric conditions, the impact of medical policy changes, variation in medical treatment, congenital abnormalities, and the economic burden of specific conditions. The KID is especially useful in studying rare pediatric conditions.

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KID/Knowledge Check

Sean: So when would a researcher want to use the SID, the NIS, or the KID? Let's take a look at some examples and answer the questions below.

Robert would like to study pediatric heart surgeries in children on a national-level. Which database(s) would Robert want to use?

  • SID
  • NIS
  • KID

Juliana would like to identify differences in asthma hospitalizations for children and adults on a national-level. Which database(s) would Juliana want to use?

  • SID
  • NIS
  • KID

James would like to identify differences in hospitalization rates of children with complications of diabetes between two neighboring states. Which database(s) would James want to use?

  • SID
  • NIS
  • KID

Select this link for the answers to the KID Knowledge Check: Answers to KID Knowledge Check

KID/Summary

Lauren: The KID is derived from the SID to permit researchers to study a broad range of conditions and procedures related to child health issues. Researchers and policymakers can use the KID to identify, track, and analyze national trends in health care utilization, access, charges and costs, quality, and outcomes. It is the only all-payer inpatient care database for children in the United States, and it is designed to permit research on rare pediatric conditions.

Sean: And let me guess, we can visit the HCUP User Support Web site to learn more about the KID?

Lauren: Absolutely. You can find more details on the HCUP User Support Web site.

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SASD/What are the SASD?

Lauren: Now that we've learned about inpatient data available from HCUP, let's take a look at available outpatient data.

Sean: I didn't realize that HCUP had outpatient databases.

Lauren: Many researchers don't realize that the HCUP databases include both inpatient and outpatient data. Outpatient data are available in the State Ambulatory Surgery and Services Databases (SASD), the State Emergency Department Databases (SEDD), and the Nationwide Emergency Department Sample (NEDS).

We'll discuss the SEDD and NEDS shortly. Let's begin by taking a look at the SASD.

The SASD include encounter-level data for ambulatory surgery and other outpatient services from hospital-owned facilities. In addition, some States provide ambulatory surgery and outpatient services from nonhospital-owned facilities.

*The term discharge is reserved to describe inpatient services in which a patient has been admitted for care and subsequently discharged. HCUP uses the term encounter in reference to outpatient services.

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SASD/Data Sources

Lauren: To better understand the SASD, let's take a look at how they are created.

Types of Facilities
The SASD include encounter-level data for ambulatory surgery and other outpatient services from hospital-owned facilities. In addition, some States provide ambulatory surgery and outpatient services from nonhospital-owned facilities.

Hospital-Owned Surgery Centers
All SASD include records from hospital-owned ambulatory surgery sites. The designation of a facility as hospital-owned is specific to its financial relationship with a hospital that provides inpatient care and not related to its physical location. Hospital-owned ambulatory surgery facilities may be physically attached to the hospital or located in a different geographic area. Additionally, some States include data from nonhospital-owned facilities.

Nonhospital-owned Surgery Centers
Some of the SASD include records from both hospital-owned and nonhospital-owned surgery centers. The availability of data from nonhospital-owned surgery centers varies by state. Nonhospital-owned facilities can include freestanding ambulatory surgical centers, lithotripsy centers, and cardiac catheterization laboratories.

HCUP Processes Data
The data are processed by HCUP to create uniformly formatted databases. Because of this uniform format, you can perform state-to-state comparisons and analyses.

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SASD/Knowledge Check

Sean: What types of care would and would not be captured in the SASD? Answer the questions below.

John has a routine colonoscopy at a hospital-owned outpatient surgery center. Would this be captured by the SASD?

  • Yes
  • No
  • Varies by state

Mary has an elective skin biopsy performed in her physician's office. Would this be captured by the SASD?

  • Yes
  • No
  • Varies by state

David has an elective knee arthroplasty done in a nonhospital-owned surgery center. Would this be captured by the SASD?

  • Yes
  • No
  • Varies by state

Select this link for the answers to the SASD Knowledge Check: Answers to SASD Knowledge Check

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SASD/File Structure

Sean: If I wanted to compare inpatient and outpatient obesity-related surgeries, would the file structure of the SASD be similar to that of the SID?

Lauren: Yes, let's take a look.

Core Variables
The SASD contain a core set of data elements including age, sex, diagnoses, hospital charges, and expected payer. While both the SID and SASD include information on procedures, this information is coded using ICD-9-CM procedure codes in the SID and a mixture of ICD-9-CM and CPT procedure codes in the SASD.

State-Specific Variables
There are state-specific data elements in the SASD. These variables include hour of admission, hours of discharge, patient race/ethnicity, and encrypted patient ID number. These elements vary by state and may or may not be available for the state(s) included in your research.

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SASD/Availability and Pricing

Lauren: The SASD are updated annually, and the number of states included grows each year. Similar to the SID, each state sets its own price for the SASD, and prices can vary. Many of the states have agreed to allow the online HCUP Central Distributor to distribute their SASD. The HCUP Central Distributor handles these transactions as a service to the states – payments for the SASD are returned directly to the states. For more information on the SASD, see the SASD Overview.

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SASD/Research Topics

Lauren: The SASD can help address a number of research topics that pertain to ambulatory surgeries. Sean could expand his research to include both inpatient and ambulatory surgery data – there has been some talk about bariatric surgeries being performed in the outpatient setting of the hospital in the near future. You could use these data to identify state-specific trends in ambulatory surgery utilization, access, charges, and outcomes. You can also use it to conduct market area research or small area variation analyses. You could even use it in combination with the SID to examine complications of ambulatory surgeries that result in inpatient admissions.

SASD/Summary

Sean: To sum it all up, the SASD include data for ambulatory surgery and other outpatient services from hospital-owned facilities. In addition, some States provide ambulatory surgery and outpatient services from nonhospital-owned facilities. The SASD files include all patients, regardless of payer, providing a unique view of ambulatory surgeries in a defined market or in a State over time. They contain a core set of clinical and non-clinical information regardless of payer, including persons covered by Medicare, Medicaid, private insurance and uninsured individuals. In addition to the core set of uniform data elements common to all SASD, some include other elements such as the patient's race.

Lauren: And you can find more information about the SASD on the HCUP User Support web site.

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SEDD/What are the SEDD?

Sean: Are any other types of outpatient care captured in HCUP databases?

Lauren: Yes, the HCUP databases also capture emergency department utilization in three databases. The State Inpatient Databases (SID) contain a universe of the inpatient discharge abstracts in participating states including those for patients who were admitted to the hospital from the emergency department. The State Emergency Department Databases (SEDD) contain the emergency department encounter abstracts in participating states for patients who were treated in an emergency department and then released. The Nationwide Emergency Department Sample (NEDS) was constructed using records from both the SID and the SEDD. The NEDS yields national estimates of emergency department visits.

Let's start by talking about the SEDD.

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SEDD/Data Sources

Lauren: The SEDD are derived from encounter abstracts and uniform billing data from hospital-based emergency department visits. Visits that result in an admission to the hospital are not included in the SEDD; rather, they are included in the SID.

 

SEDD/File Structure

Sean: My guess is that the data elements and file structure of the SEDD are similar to that of the SID and the SASD.

Core Variables
The SEDD contain a core set of data elements, including patient demographics, expected payment source (including uninsured), and all-listed diagnoses and procedures.

State-Specific Variables
There are also state-specific data elements in the SEDD. Examples of state-specific variables include CPT codes, patient race/ethnicity, and AHA hospital identifier. Similar to the SASD, the SEDD can be linked to the SID by an encrypted patient identifier for certain states.

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SEDD/Availability and Pricing

Lauren: The SEDD are released every year. Like the other state databases, the SID and the SASD, each state sets its own price for the SEDD. The cost of the SEDD varies per data set, per year. Many of the states have agreed to allow the online HCUP Central Distributor to distribute their SEDD. The HCUP Central Distributor handles these transactions as a service to the states—payments for the SEDD are returned directly to the states. For more information on the SEDD, see the SEDD Overview.

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SEDD/Research Topics

Lauren: There are many interesting ways to use the SEDD. The SEDD can be used to examine state-specific trends in emergency department utilization, access, charges, and outcomes. Researchers can also use the SEDD to conduct market area research or small area variation analyses. The SEDD can be used to identify patterns of care for patients with various demographic and clinical characteristics and to address research topics related to injury surveillance, trends in emergency department use, correlations between ED use and environmental events, and occurrence of non-fatal, preventable illnesses. For certain states, the SEDD can be used to examine emergency department visits and re-visits.

Because emergency department visits that result in an admission to the hospital are not included in the SEDD, researchers who are interested in studying all visits that originate in the ED may prefer to work with both the SEDD and the SID. Studying both of these databases will provide a more complete state-level perspective by integrating outpatient and inpatient care data. For a nationwide perspective of ED visits, researchers should use the Nationwide Emergency Department Sample, the NEDS.

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SEDD/Knowledge Check

Sean: So HCUP includes three state-level databases: the SID, the SASD, and the SEDD. When would a researcher want to use one over the other, or some combination of two or three? Answer the questions below.

Michele is studying hospital charges associated with uninsured emergency department visits that are not hospitalized. Which database(s) would Michele want to use?

  • SID
  • SASD
  • SEDD

John is interested in researching the percentage of emergency room visits for asthma that result in hospitalization in Maryland. Which database(s) would John want to use?

  • SID
  • SASD and SEDD
  • SEDD and SEDD

Andrea is conducting research on the frequency of hysterectomies in a specific state. She understands that sometimes hysterectomies are performed in both the inpatient and outpatient setting of the hospital. Which database(s) would Andrea want to use?

  • SID and SEDD
  • SID and SASD
  • SEDD and SASD

Joe would like to identify serious complications resulting from outpatient surgeries that required hospitalization. Which database(s) would Joe want to use?

  • SID and SEDD
  • SID and SASD
  • SEDD and SASD

Select this link for the answers to the SEDD Knowledge Check: Answers to SEDD Knowledge Check

SEDD/Summary

Sean: So to summarize, the SEDD capture encounter information on all emergency department visits that do not result in an admission to the same hospital. The SEDD contain the emergency department encounter abstracts in participating states and are translated into a uniform format to facilitate multi-state comparisons and analyses.

They contain a core set of clinical and non-clinical information on all patients, regardless of payer, including persons covered by Medicare, Medicaid, private insurance, and the uninsured. In addition to the core set of uniform data elements common to all SEDD, some state data include other elements, such as the patient's race.

Lauren: And you can find more information about the SEDD on the HCUP User Support Web site.

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NEDS/What is the NEDS?

Sean: I know that the HCUP SEDD contain only ED visits that are considered treat-and-release. I am interested in studying all ED visits—those which result in an inpatient admission to the same hospital as well as those that are treat-and-release?

Lauren: HCUP creates the Nationwide Emergency Department Sample (NEDS) so that researchers can investigate emergency department utilization patterns—for both types of visits—on a national level. The NEDS includes data on treat-and-release visits and on visits resulting in an inpatient admission to the same hospital. The database enables national and regional analyses of emergency department utilization, charges and outcomes.

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NEDS/Sample Design

Lauren:  The NEDS, which is the largest all-payer emergency department database that is publicly available in the United States is derived from the SID and the SEDD. 

The SID
The SID contain information on patients initially seen in the emergency room and then admitted to the same hospital.

The SEDD

The SEDD capture discharge information on all the emergency department visits that do not result in an admission to that hospital—in other words, those in which the patient is treated and released.

Sampling
The NEDS approximates a 20% sample of hospital-based emergency departments in the U.S. Using a stratified, random sampling design, a sample of hospital-based emergency departments from States participating in both the SID and the SEDD is selected, and 100% of the emergency department visits from the selected hospital-based emergency departments are retained.

Sampling Strata
Hospitals are included in the NEDS sample on the basis of five hospital characteristics (referred to as "strata" in HCUP). Stratification variables include:

  • Geographic Region – Northeast, Midwest, West, or South.
  • Location – urban or rural.
  • Teaching Status – teaching or non-teaching.
  • Control – government non-Federal (public), private not-for-profit (voluntary), or private investor owned (proprietary).
  • Trauma Center Designation.

Sample Size
The NEDS contains over 950 hospital-based emergency departments. From each selected emergency department, all visits are included; this amounts to more than 25 million unweighted observations in one data year.

The NEDS
The NEDS is designed to be nationally representative of emergency-department care. Because the NEDS sampling frame is not designed with "state" as a stratification variable, state-level analyses cannot be conducted. If you are interested in analyses by state, obtain the state-specific SID and SEDD.

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NEDS/Comparison to the SID and SEDD

Lauren: Let's take a closer look at the differences between the NEDS and the SID and the SEDD.

All Discharges vs. Sample
The NEDS is a sample of hospitals-based emergency departments, while the SID captures all discharges from community hospitals in each state and the SEDD captures all treat-and-release ED visits in each state.

Data Elements
The NEDS contains fewer data elements than the SID and the SEDD, but most of those variables are standardized. NEDS data elements include diagnosis codes, procedure codes, discharge status from the emergency department, patient demographics, expected payment source, total hospital charges for visits that resulted in an inpatient admission, and, for many visits, total emergency department charges for emergency department visits. Refer to the NEDS documentation available on HCUP-US for more detailed information.

Hospital Characteristics
The NEDS contains hospital characteristics derived from the AHA Annual Survey Database and the Trauma Information Exchange Program database. These include:

  • Region
  • Urban/rural location
  • Teaching status
  • Hospital Ownership/control
  • Trauma center designation

Trauma Center Designation
A trauma center is a hospital equipped to provide comprehensive emergency medical services 24 hours a day, 365 days per year to patients suffering traumatic injuries. The NEDS distinguishes between level I, II, and III trauma centers, as designated based on criteria developed by the American College of Surgeons' Committee on Trauma.

  • Level I and II centers have comprehensive resources and are able to care for the most severely injured. Level I centers also provide leadership in education and research.
  • Level III centers provide prompt assessment and resuscitation, emergency surgery and, if needed, transfer to a level I or II center.

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NEDS/Availability and Pricing

Lauren: The NEDS is released every year through the online HCUP Central Distributor. Pricing is shown below. Like the other HCUP databases, AHRQ offers a discounted price for students. For more information on the NEDS, see the NEDS Overview.

Price:

  • Beginning 2014 - $750 per data year
  • 2006-2013 - $500 per data-year

Student Price:

  • Beginning in data year 2013 - $150 per data-year
  • Data years 2006-2012 - $75 per data-year

Additional information is available on the HCUP User Support Web site.

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NEDS/Research Topics

Lauren: The NEDS can be used to investigate many aspects of emergency department utilization, including quality of emergency care, differences in use of ED services in rural and urban areas, impact of health policy changes, differences in admission rates, access to care, and the use of ED services by special populations.

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NEDS/Knowledge Check

Sean: Take a moment to identify whether the SID, the SEDD, the NIS or the NEDS would be better for certain research topics by answering the questions below.

Chris is investigating how nationwide emergency department visits that result in hospital admission differ from treat-and-release visits in terms of patient characteristics such as age, gender, or income level of their community. Which database would Chris want to use?

  • SID
  • SEDD
  • NIS
  • NEDS

Jacob would like to identify regional trends in emergency department use for asthma within the U.S. Which database would Jacob want to use?

  • SID
  • SEDD
  • NIS
  • NEDS

Kathryn is conducting research on how treat-and-release emergency department visits for motor-vehicle accidents vary between California and New York. Which database would Kathryn want to use?

  • SID
  • SEDD
  • NIS
  • NEDS

Amy is interested in examining national trends in costs associated with inpatient admissions that originated in the ED and those that were routinely admitted. Which database should Amy use in her research?

  • SID
  • SEDD
  • NIS
  • NEDS

Select this link for the answers to the NEDS Knowledge Check: Answers to NEDS Knowledge Check

NEDS/Summary

Sean: Before we move on, let's review. The NEDS is derived from the SID and the SEDD to allow researchers and policymakers to identify, track, and analyze national and regional trends in emergency department utilization, access, charges, quality, and outcomes.

The NEDS large sample size enables analyses of relatively uncommon disorders and procedures and special patient populations treated in the emergency department.

The NEDS is the largest all-payer database in the United States containing information on emergency department care.

Lauren: Of course, you can find this and more information about the NEDS on the HCUP User Support Web site.

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NRD/What is the NRD?

Lauren: Much like the NIS, the Nationwide Readmissions Database or NRD is derived from the SID. However, the purpose of the NRD is to enhance research on hospital readmissions. The NRD addresses a large gap in health care data—the lack of nationally representative information on hospital readmissions for all types of payers and the uninsured. The NRD is designed to allow users to investigate various types of analyses of readmissions. Criteria to determine the relationship between multiple hospital admissions for an individual patient in a calendar year is left to the analyst using the NRD.

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NRD/Sample Design

Lauren: The NRD is derived from the SID with verified patient linkage numbers that can be used to track a patient across hospital stays, while adhering to strict privacy guidelines. The NRD was created to enable analyses of national readmission rates.

The SID

Some SID include synthetic patient linkage numbers that can be used to track patients within and across hospitals in a particular state. States selected for the NRD have verified patient linkage numbers on at least 90 percent of adult discharges.

Sampling

The NRD includes community hospitals, excluding rehabilitation or long-term acute care hospitals. All discharges from the SID are included except the following:

  • Discharges from patients with an age of 0 from SID with verified patient linkage numbers on less than 90% of the discharges
  • Discharges with missing or unverified patient linkage numbers
  • Discharges with questionable patient linkage numbers, defined as 20 or more discharges in a year, hospitalized after discharged dead, and overlapping inpatient stays
  • Discharges from hospitals with more than 50 percent of their total discharges excluded for any of the above causes.

After exclusions, the NRD contains about 85 percent of SID discharges from the participating states.

Sampling Srata

NRD Sampling Strata Variables

Discharges are post-stratified in the NRD on the basis of five hospital characteristics (referred to as "strata" in HCUP) and two patient characteristics.

Stratification variables include:

  • Census Region – Northeast, Midwest, South, West.
  • Location – urban or rural
  • Teaching Status – teaching or non-teaching
  • Control – government non-Federal (public), private not-for-profit (voluntary), or private investor owned (proprietary).
  • Bed Size – small, medium, or large.
  • Patient sex
  • Patient age in five groupings (0, 1-17, 18-44, 45-64, and 65 and older)

Sample Size

The NRD contains over 14 million hospital discharge records from community hospitals excluding rehabilitation or long-term acute care hospitals. The NRD includes discharges for patients with and without repeat hospital visits in a year and those who have died in the hospital. Repeat visits may or may not be related. The criteria to determine the relationship between hospital admissions is left to the analyst using the NRD.

The NRD

The NRD is designed to be flexible to various types of analyses of national readmissions for all types of payers and the uninsured. Outcomes of interest include national readmission rates, reasons for returning to the hospital for care, and the hospital costs for discharges with and without readmissions. The NRD is not designed to support regional, state, or hospital-specific readmission analyses. If you are interested in analyses by state, obtain the state-specific SID.

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NRD/Comparison to the SID

Lauren: Let's take a closer look at the differences between the NRD and the SID. Refer to the documentation on the HCUP-US web site for more detailed information.

All Discharges in a State vs. Discharges Pooled Across States

The NRD is a convenience sample from the SID with patient linkage numbers on at least 90 percent of adult discharges. After exclusions for missing or questionable patient linkage numbers and patients aged 0 years in some states, the NRD contains about 85 percent of SID discharges from the participating states. In contrast, the SID captures all discharges from community hospitals in each state. Only some SID include patient linkage numbers.

Data Elements

The NRD and some SID include the HCUP revisit variables that contain verified synthetic linkage numbers that can be used to track a patient across hospital stays within a State. There are two key revisit variables:

  • VisitLink is the linkage variable for all inpatient stays associated with a unique patient. The value is assigned based on a unique combination of the synthetic patient linkage number provided by the HCUP Partner, date of birth, and sex. Although the term "patient linkage number" is used to describe the information in the data element VisitLink, the values are not recognizable as specific patient information. VisitLink does not include the values of the encrypted person's social security number, date of birth, or sex.
  • DaysToEvent is a data element that allows the user to calculate the number of days between admissions. For both the NRD and the SID, criteria to determine the relationship between multiple hospital admissions for an individual patient is left to the analyst. Refer to the documentation on the HCUP revisit variables available on HCUP-US for more detailed information.

Hospital Characteristics and Discharge Weights

The NRD contains hospital characteristics derived from the AHA Annual Survey Database. These include:

  • Region
  • Urban/rural location
  • Teaching status
  • Hospital Ownership/control
  • Size of hospital based on the number of beds

The NRD also include discharge weights that allow the user to calculate national estimates of readmission counts and rates. The NRD is not designed to support regional, state, or hospital-specific readmission analyses. The SID can be used to examine state-level or local-area readmission rates.

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NRD/Availability and Pricing

Lauren: The NRD is released every year through the online HCUP Central Distributor. Similar to the other HCUP databases, AHRQ offers a discounted price for students. For more information on the NRD, see the NRD Overview.

Price:

  • Beginning 2015 - $1,000 per data-year
  • 2014 - $750 per data-year
  • 2010-2013 - $500 per data-year

Student Price

  • Beginning 2015 - $200 per data-year
  • 2013-2014 - $150 per data-year
  • 2012-2012 - $75 per data-year

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NRD/Research Topics

Lauren: The NRD can be used to investigate national readmission rates by diagnosis, procedure, patient demographics, or expected payment source, costs associated with readmissions, and reasons for readmissions, and impact of health policy changes.

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NRD/Knowledge Check

Lauren: Take a moment to identify whether the SID, the NIS, the KID, or the NRD would be better for certain research topics by answering the questions below.

Dan is investigating how national readmission rates for heart attack vary by hospital characteristics such as teaching status and ownership. Which database would Dan want to use?

  • SID
  • NIS
  • KID
  • NRD

Frank would like to examine differences in readmission rates for hospitals in the Northeast. Which database would Frank want to use?

  • SID
  • NIS
  • KID
  • NRD

Katie is conducting research on hospital stays for pneumonia including total utilization in the U.S. and variation by age. Which database would Katie want to use?

  • SID
  • NIS
  • KID
  • NRD

Steven is interested in pediatric readmissions for sickle cell anemia in the U.S. Which database should Steven use in his research?

  • SID
  • NIS
  • KID
  • NRD

Select this link for the answers to the NRD Knowledge Check: Answers to NRD Knowledge Check

NRD/Summary

Sean: Before we move on, let's review. The NRD is derived from the SID that contain reliable, verified patient linkage numbers that can be used to track a person across hospitals within a State, while adhering to strict privacy guidelines. The NRD was created to enable analyses of national readmission rates.

The NRD addresses a large gap in health care data—the lack of nationally representative information on hospital readmissions for all types of payers and the uninsured.

The NRD is designed to be flexible to various types of analyses of national readmissions for all types of payers and the uninsured. The criteria to determine the relationship between multiple hospital admissions for an individual patient is left to the analyst using the NRD. Outcomes of interest include national readmission rates, reasons for returning to the hospital for care, and the hospital costs for discharges with and without readmissions. The NRD is not designed to support regional, State-, or hospital-specific readmission analyses.

Additional information is available on the HCUP User Support Web site.

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Using HCUP Data/Benefits and Limitations

Lauren: Now that we've learned about each of databases, let's take a closer look at the benefits and limitations of HCUP data.

Sean: Since HCUP databases include all discharge data from community hospitals in participating states, a large number of patients are represented, making national or regional estimates possible and allowing for the study of rare diseases.

Lauren: That's true. HCUP databases represent a large number of visit records which allows for national, regional, and state estimates. HCUP data is collected on a regular basis due to regular, routine standard hospital operations. HCUP databases also include all-payer information so groups like the uninsured can be studied. The databases have been evaluated against other sources of data to ensure accuracy. Because the databases are uniform and have been available for some time, the databases are useful for trend analysis. HCUP databases are easily accessible, and available for purchase through the HCUP Central Distributor. HCUP databases are available for State analyses, and nationwide analyses of regional and nationwide estimates.

Lastly, Supplemental files augment applicable HCUP databases with additional data elements and useful information.

Sean: All-payer information, ease of access, large number of visit records. Those benefits make a strong case for using HCUP databases. What are the limitations?

Lauren: HCUP databases have limited clinical details and differences in coding across hospitals. HCUP data include total charge information and not revenue or cost data. However, AHRQ has developed cost-to-charge ratios to estimate costs based on charge data. The data only include non-federal community hospitals. While these community hospitals account for 85% of hospitals in the U.S., HCUP does not include all hospitals. None of the HCUP databases currently include outpatient office visit data, so it's not possible to show a complete episode of care.

HCUP data does not include data on individuals outside the hospital system. HCUP national databases cannot be linked to external data such as the American Hospital Association Annual Survey of Hospitals and the Area Resource File.

Read the items below for more detail.

Benefits: Large number of visit records
HCUP includes all-payer data from Partner organizations in 47 States and the District of Columbia representing the experiences of a large number of patients receiving hospital-based inpatient and outpatient care. The large size allows for national, regional, and state estimates and for the study of rare diseases and outcomes.

Benefits: Regular, routine collection
Billing data are collected as part of standard hospital operations.

Benefits: All payers, including the uninsured
HCUP databases include the expected primary payer for the hospital stay categorized into six uniform categories: private insurance, Medicare, Medicaid, self-pay, no charge or charity, and other insurance. Other insurance may include: Workers' Compensation, TRICARE (health care for military families), and other state and local government programs.

Benefits: Uniformity in coding
Uniform coding of key data elements (such as the expected payer for the hospital bill and the patient's race/ethnicity) facilitate multi-State comparisons and analyses.

Benefits: Ease of access
HCUP databases are available for purchase through an online ordering system and simple application process.

Benefits: Available at local, State, regional, and national level
HCUP State databases can be used to investigate questions unique to one State, to compare data from two or more States, and to conduct market area research or small variation analyses. The HCUP national databases facilitate analyses of regional and national estimates of health care utilization, access, charges, quality, and outcomes.

Benefits: Supplemental files available to facilitate research
The HCUP Supplemental Files augment applicable HCUP databases with additional data elements or analytically useful information that is not available when the HCUP databases are originally released. These files allow users to convert charges to cost, add information on hospital market structure, link to information from the American Hospital Association Annual Survey of Hospitals, and perform revisit analyses on State-level data.

Limitations: Limited clinical detail
The data were originally generated as part of the billing and not specifically created for research purposes. Thus, some elements that researchers may find useful are not included in the billing data, such as information on laboratory test or medications.

Limitations: Differences in coding across hospitals
Coding of data elements (e.g., the number of diagnoses or procedures reported on a record, total charges, patients race/ethnicity) may vary by hospital.

Limitations: Lacks revenue information
HCUP data include charge information, rather than revenue or cost data. Hospital charges reflect the amount the hospital billed for the entire hospital stay and do not include professional/physician fees. Cost information can be estimated by applying the HCUP cost-ro-charge ratio supplemental file to the data of select databases.

Limitations: Doesn't include all hospital types (e.g., VA and DOD)
HCUP data are based on community, non-Federal hospital data representing over 88% of all hospitals in the US. HCUP does not include all types of hospitals such as Veteran's Administration, Department of Defense, Indian Health Service, psychiatric or long term care facilities.

Limitations: Doesn't show complete episode of care
The HCUP databases are specific to hospital-based care and, therefore, do not include information on outpatient office visits. Consequently, HCUP data cannot be used to study complete episodes of care. However, a subset of states have encrypted patient linkage numbers that can be used to examine patient encounters across time and hospital setting (e.g. inpatient, ambulatory surgery and ED).

Limitations: No data on individuals outside of the hospital system
The HCUP databases include visit information on patients treated in the hospital for an inpatient stay, ambulatory surgery, or ED visit. People not treated in the hospital are not represented in the data.

Limitations: Can't link national databases to external sources
The HCUP national databases cannot be linked to external data such as the American Hospital Association Annual Survey of Hospitals or the Area Health Resource File.

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Using HCUP Data/Which database should I use?

Lauren: Once you decide that the HCUP databases can help with your research, you then need to determine which of the databases will be most suited for your analysis. It is important to ask the right questions to decide whether HCUP can help address your research topic.

Let's take a look at Sean's research topic — national trends in obesity-related procedures – and determine which HCUP database will best fit his needs. Sean has already answered the first question:

  • What is my research question?
    • What are the national trends in utilization of obesity-related procedures?

Sean, are you looking at inpatient or outpatient data?

Sean: Currently, most obesity-related procedures are inpatient so I plan on focusing my research there.

  • Should I look at inpatient and/or outpatient data?
    • Inpatient data.

Lauren: That eliminates outpatient databases – the SASD, the SEDD, and the NEDS. The next question to ask is what variables you need for your analysis. We've talked about common data elements included in all the databases and state-specific variables that are only included when released by the states. It sounds like you'll mainly be looking at diagnoses, procedures, and possibly patient demographics.

  • What variables do I need for my analysis?
    • Diagnoses and procedures, as well as patient demographics.

Next you'll need to determine if you want national estimates.

Sean: Since I'm looking for national trends, I certainly will want national estimates. That would eliminate the SID. Correct, and if you are not specifically interested in readmission analyses, that will eliminate the NRD. That leaves just the NIS and the KID, but I'm interested in adults. That eliminates the KID and leaves the NIS as the best database for my research topic.

  • Do I want national estimates?
    • Yes.
  • Is my research limited to children?
    • No.

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Using HCUP Data/Obtaining HCUP Data

Sean: Once I've decided which databases I need for my research, how do I go about gaining access to them?

Lauren: Earlier in the course, we talked about how you would access the HCUP databases. To summarize, national and state databases, are available directly through the online HCUP Central Distributor. Before purchasing any data files from the HCUP Central Distributor, individuals must complete the HCUP Data Use Agreement Training Course. This training outlines important points in the DUA. After completing the training, you will receive a certification code. Use this code in your application for purchasing HCUP databases. Refer to the online HCUP Central Distributor to review available state data, purchase price, and years available.

Lauren: The DUA is a legally binding agreement with AHRQ that defines how you can use the HCUP data. When you sign the agreement you agree to comply with the requirements listed. If you violate the DUA, the following consequences may occur:

  • Legal consequences: You may be fined and/or sentenced to a prison term.
  • Restricted use of data: If a violation were to occur, it could have long-term effects on the credibility of other health care researchers. This misuse could result in a loss of cooperation from other agencies and lead to restricted access to data.

The DUA outlines:

  • Protection of Individual Identities by adhering to guidelines:
    1. Do not release or disclose any data where the number of observations in any given cell or tabulated data is less than or equal to 10
    2. Do not attempt to identify individuals within the HCUP data sets, including patients and providers
    3. Do not attempt to learn the identity of individuals through any deliberate technical analysis, including through vulnerability analysis or penetration testing of the data
    4. Do not publish methodology that could be used by other to identify individuals

The DUA outlines Restrictions of Hospital Identification by not publishing or reporting data that could identify individual establishments directly or by inference.

The DUA outlines appropriate Use of HCUP. You are responsible for how you and others use the data to which you have access.

  • Use the data for research, analysis, and aggregate statistical reporting.
  • Share the data with your immediate research group, if all members have signed and agree to adhere to the statutes of the DUA.
  • Merge outside data to HCUP data to conduct health care research as long as you do not attempt to identify individuals within HCUP data sets.

The DUA outlines Data Use Restrictions. You are prohibited by the HCUP DUA from

  1. Using the data for commercial or competitive purposes
  2. Using the data to determine the rights, benefits, or privileges of individual establishments
  3. Redistributing HCUP data by posting data online
  4. Contacting an institution to question, verify, or discuss the data

The HCUP DUA is consistent with HIPAA requirements for use of a limited data set.

The DUA has specific Publishing Recommendations: It is important that you properly acknowledge AHRQ and the specific databases used in your publication.

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Using HCUP Data/Knowledge Check

Sean: I'll be using the NIS through the HCUP Central Distributor for my research, but one of my colleagues, Jamie, is comparing hernia inpatient and outpatient surgeries in three different states. Can you help Jamie access the HCUP data that she'll need for her research?

Jamie will need to use the SID and the SASD for three different states. She has checked the HCUP User Support Web site and knows that two of the states are available through the HCUP Central Distributor and one is available through the state. What should she contact to begin this process?

  • The HCUP Central Distributor
  • The specific state-level Data Organizations

Select this link for the answers to the Using HCUP Data Knowledge Check: Answers to Using HCUP Data Knowledge Check

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Using HCUP Data/Statistical Programming Software

Lauren: To work effectively with the HCUP databases, you will need to use a statistical software package. SAS, SUDAAN, Stata, or SPSS are some of the most frequently used packages, but many such products are available. Working with these software tools requires some programming expertise. Because of the size and complexity of the HCUP databases, they cannot be analyzed using desktop spreadsheets or database applications.

AHRQ provides example programs in SAS, SPSS, Stata, and SUDAAN. Example programs include database load programs, format programs, examples of statistical coding, and programs designed to help users apply the HCUP tools.

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Example Programs Provided by AHRQ
  SAS® SPSS® Stata® SUDAAN®
Load Programs Yes Yes Yes  
Format Programs Yes      
Example Statistical Coding Statement Yes   Yes Yes
HCUP Tool Programs Yes      

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Tools and Reports/HCUPnet Overview

Lauren: A convenient and valuable way to access HCUP statistics is through a free online querying system known as HCUPnet. HCUPnet provides free and immediate access to national, regional, and state-level and county-level hospital inpatient statistics based on HCUP pre-aggregated statistical data. HCUPnet can generate statistical output for queries based on the National Inpatient Sample (NIS), the Kids' Inpatient Database (KID), the Nationwide Emergency Department Sample (NEDS), the Nationwide Readmissions Database (NRD), the State Inpatient Databases (SID), and the State Emergency Department Databases (SEDD). HCUPnet can generate output based on diagnosis and procedure codes and can cross-classify this output by select patient and hospital characteristics. You can also obtain ready-to-use national information on measures of health care quality based on the NIS using the AHRQ Quality Indicators.

HCUPnet also provides national estimates of 30 day readmissions from the Nationwide Readmissions Database (NRD). Additionally, HCUPnet provides community-level statistics for participating States, which includes volume, rates, and costs for all inpatient discharges in counties and sub-State regions and by selected diagnosis and procedure categories, including AHRQ Prevention Quality Indicators (PQIs) and Pediatric Quality Indicators (PDIs).

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Tools and Reports/Using HCUPnet

Lauren: Here we are at the HCUPnet home page. Follow the directions to use HCUPnet to get a national perspective on how the number of obesity-related procedures has changed in the past few years. Sean will appreciate the help.

Use HCUPnet to obtain a national perspective on how the number of obesity-related procedures has changed in the past few years.

Several options exist for assessing different types of statistics available on the HCUPnet home page, such as creating a new analysis or getting quick statistics tables.

Because we are interested in the total number of national discharges, click Create a New Analysis.

Now you have the choice to select setting of care by Inpatient, Emergency Department, Ambulatory Surgery or Community. For this example, click Inpatient, to move on.

This screen gives you the option of how you would like to analyze the data by choosing Descriptive Statistics, Trends, or Rank Order. For this query, click Trends because we are interested in seeing how the number of obesity-related procedures has changed through the years.

This screen allows you to select the data on a specific diagnosis or procedure. For this query, click on "Yes" to get statistics about specific conditions, diseases, surgeries, or procedures.

Now you choose how you want to classify diagnosis or procedures. Click "Choose a Classification".

Under this category - Choose how you want to classify diagnoses or procedures, click on the drop-down arrow. Select Medicare-Severity Diagnosis Related Groups (MS-DRG).

The category "Choose your diagnosis" will popup below. Click in the text box. This field will populate with items to choose. Type "619 O.R. procedures for obesity w mcc". This will populate in the window.

Now you are ready to create your analysis. Click "Create Analysis".

The Data Use Agreement for HCUPnet appears. Select "Accept" after reading this page.

The results from your analysis appear from 2008 through 2014. The left side of the screen now shows a side navigation bar. Click "Z-Test Calculator" at the bottom of the navigation bar.

Under Z Test Calculator, ESTIMATE 1 and ESTIMATE 2 appear. The blank boxes allow the user to put in discharges and standard errors. Under ESTIMATE 1 and ESTIMATE 2, use the numbers from the analyses. For this example, we will fill in years 2008 and 2014 discharges and standard errors. Click "Calculate".

The standard errors results will display below the calculate button. Now we would like to see the data in a graphical format. Click on "Graph Table" in the upper right hand corner.

All years of data - 2008 through 2014 appear in a graphical format. You can email, download it to Excel or CSV format, hide the standard errors, or print this graph. The number of operating room procedures for obesity from 2008-2014 appears in a graph.

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Tools and Reports/HCUP Tools

Sean: Lauren, HCUPnet seems very useful. It's a nice way to get a feel for the HCUP data before purchasing the full files.

Lauren: Yes, in addition to HCUPnet, AHRQ has developed many free software tools to help researchers make the most of HCUP data. These tools are available at no cost and can be downloaded from the HCUP-US Web site. Read about these tools below.

Chronic Condition Indicator

  • Categorizes ICD-9-CM and ICD-10-CM diagnosis codes into one of two categories:
    • Chronic
    • Not chronic

Elixhauser Comorbidity Software

  • Identifies major comorbidities, such as congestive heart failure and HIV/AIDS in hospital discharge records.
  • Based on the ICD-9-CM and ICD-10-CM coding schemes.

Procedure Classes Software

  • Offers users an easy way to classify procedure codes into one of four broad categories:
    • Minor Diagnostic
    • Minor Therapeutic
    • Major Diagnostic
    • Major Therapeutic.
  • Based on the ICD-9-CM and ICD-10-CM coding schemes.
  • Allows the researcher to determine if:
    • A procedure is diagnostic or therapeutic.
    • A procedure is minor or major in terms of invasiveness and/or resource use.

Clinical Classifications Software (CCS)

Utilization Flags

  • Indicates utilization of procedures and services such as ICU, CCU, NICU and specific diagnostic tests and therapies
  • Based on
    • UB-92 revenue codes
    • ICD-9-CM procedure codes
    • ICD-10-PCS procedure codes and Uniform Billing (UB-40) revenue codes

Surgery Flags

Provides a method for identifying surgical procedures and encounters using ICD-9-CM and CPT-based inpatient and ambulatory surgery data.

Quality Indicators

Quality Indicators (QIs) are measures of health care quality that utilize readily available hospital inpatient administrative data:

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Tools and Reports/HCUP Supplemental Files

Lauren:  Along with the various HCUP tools, AHRQ provides supplemental files for use in conjunction with the HCUP databases. 

Cost-to-Charge Ratio Files

  • Allows the conversion of charge data to cost estimates in the HCUP SID, NIS, KID, and NRD.
    • Costs tend to reflect the actual costs of delivering care.
    • Charges represent what the hospital billed for the care.
  • Hospital-level files designed to supplement the HCUP SID, NIS, KID, and NRD.

Hospital Market Structure Files

  • Contain measures of hospital market competition
  • Hospital-level files designed to be merged with HCUP NIS, KID or SID databases

American Hospital Association Linkage Files

  • Allow for linkage of HCUP hospital identifiers to American Hospital Association Annual Survey Databases (Health Forum, LLC © 2012)
  • Hospital-level files designed to supplement data elements in the SID, SASD, and SEDD databases.

HCUP Supplemental Files and Variables for Revisit Analysis

  • Facilitate analyses of patient visits across time and settings (inpatient, emergency department, ambulatory surgery)
  • Adhere to strict privacy guidelines
  • Discharge-level files designed to be merged with HCUP SID, SASD, and SEDD

Trends Weights Files

  • Provide trend weights and data elements which are consistently defined across data years
  • Facilitate longitudinal analyses
  • Discharge-level files:
    • NIS-Trends
    • KID-Trends

Tools and Reports/Fast Stats

Lauren: AHRQ has another on-line tool to help users analyze the data, which is called HCUP Fast Stats. Fast Stats is based on the latest HCUP data. This tool provides:

  • Easy access to the latest HCUP-based statistics for specific health information topics
  • Visual statistical displays, such as graphs, trend figures, and simple tables to convey complex information at a glance, and:
  • Timely topic-specific national and State-level statistics.

Currently, Fast Stats includes three topics, including statistics, at the State and National levels.

State Trends in Hospital use by Payer topic examines 10-year State-level trends in hospital inpatient stays and emergency department (ED) visits by payer. State-level trends are presented overall and for five types of hospitalization (maternal, mental health, injury, surgical, and medical) stratified by expected payer (Medicare, Medicaid, private insurance, and the uninsured).

The National Hospital Utilization and Costs topic presents information on trends in inpatient stays including the most common diagnoses and the most common operations.

The Opioid-Related Hospital Use topic provides information on opioid-related inpatient stays and ED visits by age group, sex, community-level income, and rural/urban location. Trends are presented graphically as population-based rates for the United States and by State.

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Tools and Reports/HCUP Reports

Lauren: AHRQ also offers a number of publications useful to researchers. I initially learned about HCUP data after seeing references in publications released by AHRQ such as the The National Healthcare Quality and Disparities Report (QDR). HCUP data have also been used extensively in articles published in peer-reviewed journals. Information about the latest HCUP publications and citations for journal articles based on HCUP data, tools, or products, appear on the HCUP User Support Website.

Congressionally Mandated Report: The National Healthcare Quality and Disparities Report

  • The first comprehensive, national effort to measure the quality of care and differences in access and use of health care services for various populations.
  • Include a broad set of performance measures that can serve as baseline views of the quality of health care and differences in the use of services.
  • Developed, in part, using HCUP data.
  • Have provided great insight into the current state of our health care system.

HCUP Statistical Briefs

  • Present simple, descriptive statistics on a variety of specific, focused topics.
  • Examples include hospitalizations in the elderly population and reasons for being admitted to the hospital through the emergency department.
  • Are available at no cost on the HCUP User Support Web site.

HCUP Infographics

  • Infographics provide a visual presentation of Statistical Brief data.
  • Are available at no cost on the HCUP User Support Web site.

ICD-10-CM/PCs Resources

The ICD-10-CM/PCS resources summarize key issues anticipated by researchers when analyzing health services outcomes using HCUP databases that include International Classification of Diseases, Tenth Revision, Clinical Modification/Procedure Coding System or ICD-10-CM/PCS coding.

HCUP Method Series

  • Method Series reports feature a broad area of methodological information on the HCUP databases and software tools.
  • Are available at no cost on the HCUP User Support Web site.

HCUP Research Spotlights

  • Highlights peer-reviewed journal publications that feature data, software products and tools.
  • Are available at no cost on the HCUP User Support Web site.

HCUP Publication Search

  • Allows a search of the Peer-Reviewed Journals, Other Publications which include government publications.
  • Simple and advanced searches are available

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User Support/Overview

Sean: Lauren, AHRQ provides so many resources for health researchers like me, but what if I need help later using HCUPnet on my own? Or what if I need specific help finding out how to purchase a database?

Lauren: HCUP provides user support services to help you with questions about the various HCUP products and tools. There are a number of ways to access technical assistance.

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General Information about HCUP resources

General information
https://www.hcup-us.ahrq.gov/home.jsp

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HCUP Online Tutorial Series

HCUP Online Tutorial Series provides HCUP data users with information about HCUP data and tools, and training on technical methods for conducting research with HCUP data. In addition to this tutorial, HCUP-provides 7 free tutorials for users of HCUP data. HCUP Sample Design, Load and Check Data, Producing National HCUP Estimates, Calculating Standard Errors, Multi-year Analysis, Nationwide Readmissions Database, and HCUP Tools Loading.

https://www.hcup-us.ahrq.gov/tech_assist/tutorials.jsp

HCUP Online Tutorial Series provides HCUP data users with information about HCUP data and tools, and training on technical methods for conducting research with HCUP data.

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Technical Assistance

Technical Assistance - HCUP User Support:

E-mail: hcup@ahrq.gov
Phone: 1-866-290-HCUP (4287)

HCUP Frequently Asked Questions
https://www.hcup-us.ahrq.gov/tech_assist/faq.jsp

HCUP Central Distributor

Lauren: The HCUP Central Distributor is an online web site that accepts, processes, and fulfills applications for the purchase of HCUP databases. HCUP Nationwide and State Databases are available for purchase online through the HCUP Central Distributor to applicants who complete the HCUP Data Use Agreement (DUA) Training and sign an HCUP DUA. Nationwide databases are delivered via secure digital download. State databases are delivered on CD/DVD.

E-mail: hcup@s-3.com
Phone: 1-866-290-HCUP (4287)
Fax: 1-866-792-5313

https://www.hcup-us.ahrq.gov/techassist.jsp

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Lauren: The HCUP User Support Web site is a "great" resource. You can use it to review extensive documentation about HCUP data, tools and products, access HCUPnet, and find a comprehensive listing of HCUP-related publications and reports.

Sean: What if I'm looking for more interactive guidance on working with HCUP data?

Lauren: The HCUP Online Tutorial Series provides HCUP data users with information about HCUP data and tools, and training on technical methods for conducting research with HCUP data. The courses in the HCUP Online Tutorial Series are designed to answer technical questions you may have related to HCUP data and programs. Available tutorials are:

Sean: Is HCUP Technical Assistance like the technical assistance I've called to try to fix my computer?

Lauren: HCUP Technical Assistance is similar, but better! HCUP Technical Assistance is provided by research personnel trained in epidemiology, health services research, statistics, economics, and medicine. While they cannot provide detailed programming or analytic support, they do provide detailed, expert advice on HCUP databases and other related products. They usually respond within three business days.

Contact Technical Assistance by e-mail: hcup@ahrq.gov or by phone (866) 290-HCUP.

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User Support/Knowledge Check

Lauren: Let's review what HCUP User Support does and what it doesn't do. Read each statement below and determine whether or not it is provided by HCUP User Support.

  • Provides guidance on how to use HCUP data
  • Contacts states directly for researchers
  • Validate statistical software code
  • Review manuscripts
  • Provides help using HCUPnet
  • Collects user feedback and suggestions for improvement
Select this link for the answers to the User Support Knowledge Check: Answers to User Support Knowledge Check

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Summary/Review

Sean: Thanks, Lauren. I've certainly learned a lot about HCUP today. Let's review some of the key topics that we discussed.

HCUP Databases
HCUP databases provide a wealth of information to enhance your health care research and promote positive changes in health care. HCUP data:

  • Include inpatient and outpatient care
  • Capture all discharges from community hospitals in participating states
  • Support cutting-edge research

Learn more about these databases on the HCUP User Support Web site.

Software Tools and Supplemental Files
AHRQ has developed several software tools and supplemental files to help researchers make the most of HCUP data. Detailed information about these tools is available from the HCUP User Support Web site.

Research Publications
HCUP data are used in numerous research publications, including many peer-reviewed journals. Citations for journal articles based on HCUP data, tools, or products appear on the HCUP User Support Web site.

AHRQ-authored publications and reports that rely on HCUP data, such as HCUP Method Series and Statistical Briefs, are also available on the User Support Web site.

User Support
HCUP provides user support to help address your questions about HCUP databases and tools. You can access technical assistance via phone or e-mail.

Learn more about user support on the HCUP User Support Web site.

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Summary/Feedback

Lauren: Thank you for completing the course! I hope that I've answered your questions about the HCUP project and databases.

If I haven't, remember that HCUP provides user support and additional information online. Check the HCUP US Web site or contact Technical Assistance for answers to your questions.

Please take a moment to provide AHRQ with course feedback. Click the link below to e-mail us your comments:
hcup@ahrq.gov

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Answers: Introduction/Knowledge Check

Are these characteristics of HCUP databases? Yes or no?

  • The foundation are inpatient and outpatient billing data (Yes)
  • Survey-based (No)
  • Includes information on the uninsured (Yes)
  • From non-Federal community hospitals (Yes)
  • Includes both inpatient and outpatient care (Yes)
  • Captures all or nearly all hospitalizations and visits (Yes)
  • Includes physician office visits (No)

Good job! You've identified all of the HCUP data characteristics. The foundations of HCUP data are derived from non-Federal community hospital billing data and include inpatient care and certain components of outpatient care.

To return to the Overview Knowledge Check, select this link: Return to Overview Knowledge Check

 

Answers: SID/Knowledge Check

Jane has a Cesarean section and remains in the hospital for two days. Would this record be included in the SID?

  • Yes. This care would be included in the SID because Jane would have been admitted to the hospital for the Cesarean section.

Madison receives routine vaccines and a check-up at her doctor's office. Would this be captured in the SID?

  • No. This would not be included in the SID because Madison received this care at her physician's office and was not admitted to the hospital.

Mark is released after receiving outpatient treatment for a broken leg. Would this record be included in the SID?

  • No. This would not be included because Mark was treated as an outpatient and the SID only captures inpatient hospital information.

Helen is admitted to a hospital with pneumonia. Would the record of her hospital treatment be included in the SID?

  • Yes. Helen's care would be included in the SID because she has been admitted to the hospital.

To return to the SID Knowledge Check, select this link: Return to SID Knowledge Check

 

Answers: NIS/Knowledge Check

Anna would like to identify differences in pneumonia hospitalizations in Maryland, as compared with Florida. Which database would Anna want to use?

  • SID. Because Anna would like to compare two states, it is best to use the SID. The NIS should not be used for state-level analyses.

Linda would like to identify national trends in diabetes hospitalizations. Which database would Linda want to use?

  • NIS. Because Linda would like to identify national trends, it is best to use the NIS.

Tim would like to identify regional trends in hospitalizations for coronary artery bypass graft (CABG) procedures within the U.S. Which database would Tim want to use?

  • NIS. Tim should use the NIS to conduct this regional analysis on CABG surgeries. The NIS can support national and regional research. Beginning with the 2012 data year, the NIS can also provide estimates by census division.

To return to the NIS Knowledge Check, select this link: Return to NIS Knowledge Check

 

Answers: KID/Knowledge Check

Robert would like to study pediatric heart surgeries in children on a national-level. Which database(s) would Robert want to use?

  • KID. The KID is the best choice to study hospitalizations on this rare pediatric procedure.

Juliana would like to identify differences in asthma hospitalizations for children and adults on a national-level. Which database(s) would Juliana want to use?

  • NIS and KID. Juliana can use both the NIS and the KID to determine the differences between pediatric and adult inpatient services.

James would like to identify differences in hospitalization rates of children with complications of diabetes between two neighboring states. Which database(s) would James want to use?

  • SID. Because James would like to compare rates of children hospitalized in two states, it is best to use the SID. Neither the NIS nor the KID should be used for state-level analyses.

To return to the KID Knowledge Check, select this link: Return to KID Knowledge Check

 

Answers: SASD/Knowledge Check

John has a routine colonoscopy at a hospital-affiliated surgery center. Would this be captured by the SASD?

  • Yes. This procedure would be captured by the SASD because the surgery was performed in the outpatient setting of a hospital.

Mary has an elective skin biopsy performed in her physician's office. Would this be captured by the SASD?

  • No. This procedure would not be captured in the SASD because it was performed in a physician's office instead of a surgery center.

David has an elective knee arthroplasty done in a nonhospital-owned surgery center. Would this be captured by the SASD?

  • Varies by state. Not all states capture ambulatory surgeries conducted in non hospital-owned surgery centers, but some do. The HCUP User Support Web site provides documentation detailing which states capture ambulatory surgery data from nonhospital-owned facilities.

To return to the SASD Knowledge Check, select this link: Return to SASD Knowledge Check

 

Answers: SEDD/Knowledge Check

Michele is studying hospital charges associated with uninsured emergency department visits that are not hospitalized. Which database(s) would Michele want to use?

  • SEDD. Michele would want to use the SEDD because it captures emergency room visits. The SEDD includes information on uninsured visits — including charge data.

John is interested in researching the percentage of emergency room visits for asthma that result in hospitalization in Maryland. Which database(s) would John want to use?

  • SID and SEDD. The SEDD capture emergency room visits that do not result in admission to the hospital, while the SID include emergency room visits that result in admission to the hospital. John needs to use both the SID and the SEDD to look at all patients who sought emergency room care for asthma.

Andrea is conducting research on the frequency of hysterectomies in a specific state. She understands that sometimes hysterectomies are performed as a same-day surgical procedure. Which database(s) would Andrea want to use?

  • SID and SASD. Andrea should use both the SID and the SASD to capture all hysterectomy records.

Joe would like to identify serious complications resulting from outpatient surgeries that required hospitalization. Which database(s) would Joe want to use?

  • SID and SASD. Outpatient surgeries are captured in the SASD. If a patient was hospitalized after an outpatient surgery because of a surgical complication, the hospitalization would be captured in the SID. In certain states that offer encrypted patient identifiers, a patient can be tracked across the SID and the SASD.

To return to the SEDD Knowledge Check, select this link: Return to SEDD Knowledge Check

 

Answers: NEDS/Knowledge Check

Chris is investigating how nationwide emergency department visits that result in hospital admission differ from treat-and-release visits in terms of patient characteristics such as age, gender, or income level of their community. Which database would Chris want to use?

  • NEDS. The NEDS captures nationwide emergency department visits that result in hospital admission as well as treat-and-release visits. It includes information on patient characteristics. The NEDS would be the best database for Chris to use.

Jacob would like to identify regional trends in emergency department use for asthma within the U.S. Which database would Jacob want to use?

  • NEDS. Regional estimates of emergency department visits—both treat-and-release and visits which resulted in an inpatient admission to the same hospital --for a particular diagnosis can be produced from the NEDS database.

Kathryn is conducting research on how potentially preventable treat-and-release emergency department visits vary between California and New York. Which database would Kathryn want to use?

  • SEDD. The SEDD capture treat-and-release emergency room visits on a state-level. These databases must be used to perform any state-level analyses on treat-and-release emergency department visits.

Amy is interested in examining national trends in costs associated with inpatient admissions that originated in the ED and those that were routinely admitted. Which database should Amy use in her research?

  • NIS. Amy is looking for national data on inpatient admissions. The NIS contains data on all admissions—-those that originated in the emergency department as well as direct admissions not originating in the emergency department.

To return to the NEDS Knowledge Check, select this link: Return to NEDS Knowledge Check

 

Answers: NRD/Knowledge Check

Dan is investigating how national readmission rates for heart attack vary by hospital characteristics such as teaching status and ownership. Which database would Dan want to use?

  • NRD. The NRD was created to enable analyses of national readmission rates.

Frank would like to examine differences in readmission rates for hospitals in the Northeast. Which database would Frank want to use?

  • SID. Many of the SID include the HCUP revisits variable that facilitate analysis of State-level readmission rates. The NRD is not designed to support regional, State-, or hospital-specific readmission analyses.

Katie is conducting research on hospital stays for pneumonia including total utilization in the U.S. and variation by age. Which database would Katie want to use?

  • NIS. The NIS is the best HCUP database for estimating total utilization in U.S. hospitals.

Steven is interested in pediatric readmissions for sickle cell anemia in the U.S. Which database should Steven use in his research?

  • NRD. The NRD was created to enable analyses of national readmission rates for pediatrics and adults. The KID cannot be used for readmission analyses.

To return to the NRD Knowledge Check, select this link: Return to NRD Knowledge Check

 

Answers: Using HCUP Data/Knowledge Check

Jamie will need to use the SID and the SASD for three different states.

  • The HCUP Central Distributor
  • The specific state-level Data Organizations

Jamie will have to contact the HCUP Central Distributor to access two of the states' databases and the Data Organization in the state that does not participate in the CD.

What does she need to do to purchase this data?

  • Jamie will be required to take the DUA training course as well as sign a DUA for each database she will be purchasing.

To return to the Using HCUP Data Knowledge Check, select this link: Return to Using HCUP Data Knowledge Check

 

Answers: User Support/Knowledge Check

  • HCUP Technical Assistance does provide guidance on how to use HCUP data.
  • HCUP Technical Assistance does not contact states directly for researchers.
  • HCUP Technical Assistance does provide help using HCUPnet.
  • HCUP Technical Assistance does collect user feedback and suggestions for improvement.

To return to the User Support Knowledge Check, select this link: Return to User Support Knowledge Check

 

Resources

HCUP User Support Website: https://www.hcup-us.ahrq.gov/

HCUP Databases: https://www.hcup-us.ahrq.gov/databases.jsp

HCUP Tools and Software: https://www.hcup-us.ahrq.gov/tools_software.jsp

HCUP Reports: https://www.hcup-us.ahrq.gov/reports.jsp

HCUP News and Events: https://www.hcup-us.ahrq.gov/news.jsp

HCUP Technical Assistance: https://www.hcup-us.ahrq.gov/techassist.jsp

For information on obtaining the HCUP databases, please contact the HCUP Central Distributor:

For questions on the HCUP Data Use Agreement, please refer to the Web-based tutorial: HCUP Data Use Agreement Training.

To search an HCUP topic, please review the Index Page.

To reach HCUP User Support, please contact us via e-mail or phone:

This course may not be copied, photocopied, reproduced, translated, transmitted, or electronically converted in whole or in part without the prior written consent of the Agency for Healthcare Research and Quality (AHRQ), Department of Health and Human Services.

Created by Allen Communication Learning Services for the Agency for Healthcare Research and Quality (AHRQ)

We are interested in your comments and suggestions about this electronic training module. Please contact us at hcup@ahrq.gov.

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Internet Citation: HCUP Overview Course - Accessible Version. Healthcare Cost and Utilization Project (HCUP). August 2018. Agency for Healthcare Research and Quality, Rockville, MD. www.hcup-us.ahrq.gov/HCUP_Overview/HCUP_Overview/index508_2018.jsp.
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Last modified 8/7/18