HCUP e-News: the electronic newsletter of the Healthcare Cost and Utilization Project


Winter 2017
Issue #53


Contents

News and Announcements: Notable news from HCUP
Databases and Products: New database and product releases
Publication Spotlights: Recent works incorporating HCUP data and tools
HCUP Q&A: Answers to your HCUP questions
HCUP Events: Upcoming HCUP conferences and meetings

Missed the last e-News? Read it on the HCUP-US website.


News and Announcements

Now Available: The 2015 National Inpatient Sample (NIS)

The 2015 National Inpatient Sample (NIS) was released in November. The NIS is the largest inpatient care database in the United States. It contains charge information on all patients, regardless of payer, including persons covered by Medicare, Medicaid, or private insurance and the uninsured. The NIS is a powerful database that contains data from approximately 7 million hospital stays in 46 States and the District of Columbia, covering more than 97 percent of the U.S. population.

Following the transition to the International Classification of Diseases, Tenth Revision, Clinical Modification/Procedure Coding System (ICD-10-CM/PCS) on October 1, 2015, the file structure of the 2015 NIS has changed. Users are encouraged to review the ICD-10-CM/PCS Resources Page prior to analyzing outcomes affected by this change in the ICD coding scheme. Additional information also is provided within a separate announcement specific to the file structure of the HCUP Nationwide databases as well as the HCUP Q&A section of this newsletter.

NIS data can be weighted to produce national estimates, allowing researchers and policymakers to identify, track, and analyze national trends in healthcare utilization, access, charges, quality, and outcomes. Its vast size enables analyses of infrequent conditions, uncommon treatments, and special patient populations.

The 2015 NIS is available for purchase through the HCUP Central Distributor.

Now Available: The 2015 Nationwide Readmissions Database (NRD)

The 2015 Nationwide Readmissions Database (NRD) was released in November. The NRD is a unique and powerful database designed to support analyses of national readmission rates for all payers and the uninsured. This database addresses a large gap in healthcare data—the lack of nationally representative information on hospital readmissions for all ages. Unweighted, the NRD contains data from approximately 17 million discharges each year. Weighted, it estimates roughly 36 million discharges.

The NRD is drawn from the State Inpatient Databases (SID). The 2015 NRD was constructed from 27 States with reliable, verified patient linkage numbers in the SID that could be used to track patients across hospitals within a State, while adhering to strict privacy guidelines.

Following the transition to ICD-10-CM/PCS on October 1, 2015, the file structure of the 2015 NRD has changed. Users are encouraged to review the ICD-10-CM/PCS Resources Page prior to analyzing outcomes affected by this change in the ICD coding scheme. Additional information also is provided within a separate announcement specific to the file structure of the HCUP Nationwide databases as well as in the HCUP Q&A section of this newsletter.

The 2015 NRD is available for purchase through the HCUP Central Distributor.

Coming Today: 2015 Nationwide Emergency Department Sample (NEDS)

AHRQ plans to release the 2015 Nationwide Emergency Department Sample (NEDS) on December 20th. The NEDS is the largest all-payer emergency department (ED) database in the United States. It contains information about geographic, hospital, patient, and visit characteristics.

The NEDS enables analyses of ED utilization patterns and yields information that supports public health professionals, administrators, policymakers, and clinicians as they make decisions regarding this critical source of care.

Like the 2015 NIS and NRD, the file structure of the 2015 NEDS will change because of the transition to ICD-10-CM/PCS on October 1, 2015. Users are encouraged to review the ICD-10-CM/PCS Resources Page prior to analyzing outcomes affected by this change in the ICD coding scheme. Additional information also is provided within a separate announcement specific to the file structure of the HCUP Nationwide databases as well as the HCUP Q&A section of this newsletter.

Once released, the 2015 NEDS will be available for purchase through the HCUP Central Distributor.

2015 HCUP Nationwide Databases: Revised File Structure

On October 1, 2015, the United States transitioned from using the International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) to ICD-10-CM/PCS code sets for reporting clinical diagnoses and inpatient procedures. The introduction of ICD-10-CM/PCS on October 1, 2015, means that the 2015 NIS, NRD, and NEDS include a combination of codes:

To alert users to this change in coding systems, the file structures of the 2015 NIS, NRD, and NEDS have changed. The first 3 quarters (Q1–Q3) of data (with ICD-9-CM codes) are stored separately from the fourth quarter (Q4) data (with ICD-10-CM/PCS codes). In addition, the names of diagnosis- and procedure-related data elements under ICD-10-CM/PCS have been changed to identify the coding scheme. Data elements based on the HCUP Tools that are derived from ICD-10-CM/PCS codes are not included in the Q4 data, but beta versions of the programs to assign the HCUP Tools are available for download on the HCUP Tools & Software section of the HCUP User Support (HCUP-US) website.

Now Available: Best Practices Checklist for Working With the NIS

To ensure researchers' appropriate use of the NIS, AHRQ released a Checklist for Working with the NIS. The checklist, posted on the HCUP-US website, helps researchers, peer manuscript reviewers, and journal editors understand the NIS database design, its strengths and limitations, and how it has changed over time. It provides a step-by-step guide detailing key elements to consider when evaluating NIS studies. Additionally, it refers to informational resources covering four key topics: NIS data use and acknowledgements, research design, data analysis, and the transition from ICD-9-CM to ICD-10-CM/PCS. The checklist was derived from the article by Khera and colleagues noted in the Publications section below.

HCUP Fast Stats Data Updates

HCUP Fast Stats provides easy access to the latest HCUP-based statistics for health information topics. Fast Stats uses visual statistical displays in stand-alone graphs, trend figures, or simple tables to convey complex information at a glance. Recently, this online tool was updated to add new information to three existing topics.

For additional information, please refer to the Fast Stats Frequently Asked Questions page or contact HCUP User Support.


Databases and Products

Recently Released: 2015 State Databases

Since October 2017, the following State Databases have been released:

In addition, the 2015 National Inpatient Sample (NIS) and Nationwide Readmissions Database (NRD) have been released. The 2015 Nationwide Emergency Department Sample (NEDS) will be released December 20.

Complete listings of available databases by year can be found in the Database Catalog on the HCUP-US website. Databases can be purchased online through the HCUP Central Distributor, and aggregated statistics for selected States can be accessed via HCUPnet.

For database purchasing questions, please contact the HCUP Central Distributor.


Publication Spotlights

New HCUP Statistical Briefs Posted on HCUP-US

Since October 2017, the following HCUP Statistical Briefs have been released:

To access these and other Statistical Briefs, please visit the Statistical Briefs page on the HCUP-US website.

New HCUP Method Series Report Now Available

Since October 2017, the following Methods Series Report has been released:

Method Series Report #2017-04: Population Denominator Data for Use With the HCUP Databases (Updated with 2016 population data) identifies relevant sources of population data through the 2016 data year that can be used with the HCUP databases to calculate rates of hospital care events per population.

This report and other HCUP reports can be found on the HCUP Reports page.

Publications Using HCUP Data

Khera R, Angraal S, Couch T, et al. Adherence to methodological standards in research using the National Inpatient Sample. JAMA. 2017;318(20):2011-8.

This study reviews a sample from over 1,000 studies published from January 2015 through December 2016 using the National Inpatient Sample (NIS) to determine adherence to appropriate research practices for use and reporting. This article abstract is available via PubMed.

Berry JG, Ash AS, Cohen E, et al. Contributions of children with multiple chronic conditions to pediatric hospitalizations in the United States: a retrospective cohort analysis. Hosp Pediatr. 2017;7(7):365-72.

This study uses the 2012 Kids' Inpatient Database (KID) along with the HCUP Chronic Condition Indicator (CCI) to assess the extent to which children with multiple chronic conditions use pediatric inpatient care in the United States and which chronic conditions are the key drivers of hospital resource use. This article abstract is available via PubMed.

To read additional recently published articles featuring HCUP data, please visit the Research Spotlights page on the HCUP-US website.


HCUP Q&A

Question: I am interested in purchasing the 2015 NIS and NRD. According to the documentation on the HCUP-US website, the file structures are different compared with earlier years, certain data elements have been renamed, and several data elements have been removed. Before I move forward with my purchase, I have a few questions—the answers to these questions will help me better understand the documented changes.

Answers:

Is there an option to purchase a version of the 2015 NIS and NRD that is structured similarly to prior years?

The HCUP Central Distributor does not have a version available of the 2015 NIS and NRD that is structured similarly to prior years. The 2015 Nationwide databases, including the NEDS, were structured differently to demarcate the transition to the ICD-10-CM/PCS coding system on October 1, 2015.

I am not finding certain diagnosis- and procedure-related data elements on the 2015 NIS and NRD Core Files that were present in the 2014 Core Files. Where did they go?

Data elements based on diagnoses and procedures have been moved out of the 2015 NIS and NRD Core Files and placed into their respective 2015 Diagnosis and Procedure Groups Files. The Core Files continue to be an annual file containing commonly used data elements not affected by the transition to ICD-10-CM/PCS, such as patient age, expected primary payer, and total charges. Additional information on the location of diagnosis- and procedure-related data elements in the 2015 NIS and NRD are available at https://www.hcup-us.ahrq.gov/db/nation/nis/nisdde.jsp and /db/nation/nrd/nrddde.jsp.

Several data elements now include the prefix "I10_" in the Q4 files. What does this mean?

As noted above in response to the previous question, diagnosis- and procedure-related data elements were moved out of the Core File and placed into the Diagnosis and Procedure Groups File. For both the 2015 NIS and NRD, the Diagnosis and Procedure Groups File has been split into two files by discharge quarter (Q1–Q3 indicating discharge quarters 1–3 with ICD-9-CM data and Q4 for discharge quarter 4 with ICD-10-CM/PCS data). The Q4 Diagnosis and Procedure Groups File includes the ICD-10-CM/PCS diagnosis and procedure codes in data elements with the prefix "I10_".

Several data elements present in the Q1–Q3 files are missing from the Q4 files. For instance, I am not finding the Clinical Classification Software (CCS), Chronic Condition Indicators (CCIs), or Procedure Classes, to name a few. Where can I find these data elements?

Data elements derived from AHRQ Software Tools (i.e., CCS, CCI, and Procedure Classes) are not available in the Q4 files because the ICD-10-CM/PCS versions of these tools still are under development. This is applicable to the Diagnosis and Procedure Groups File for Q4 as well as the Disease Severity Measures File for Q4. Beta versions of the ICD-10 Software Tools are available at https://www.hcup-us.ahrq.gov/tools_software.jsp. For users wishing to append the ICD-10-CM/PCS AHRQ Software Tools to the 2015 Nationwide databases, ASCII versions of the ICD-10 software tools are available for use with user analytic software such as SAS, Stata, and SPSS.

Is there any guidance available for users performing a longitudinal trend analysis including ICD-10-CM/PCS data?

Users are encouraged to review the ICD-10-CM/PCS Resources Page on HCUP-US for guidance on analyzing outcomes that may be affected by the transition to the ICD-10-CM/PCS coding system. Several reports are available that offer HCUP recommendations for reporting trends spanning the ICD-9-CM and ICD-10-CM/PCS coding systems. Also provided are other Federal or State Web-related resources with information on ICD-10-CM/PCS.


HCUP Events

For a complete list of HCUP presentations and events, visit the HCUP Events Calendar.


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