User Support

December 2016

Audrey J. Weiss, Ph.D., Marguerite L. Barrett, M.S., Kevin C. Heslin, Ph.D., and Carol Stocks, Ph.D., R.N.



Introduction

Mental illnesses are common in the United States. In 2014, there were an estimated 43.6 million adults aged 18 years or older in the United States with a mental, behavioral, or emotional disorder during the past year, representing 18.1 percent of all U.S. adults.¹ Approximately one in eight visits to emergency departments (EDs) in the United States involves mental and substance use disorders (M/SUDs).² Between 2007 and 2011, the rate of ED visits related to M/SUDs increased by over 15 percent.³ ED visits involving M/SUDs are considered potentially avoidable—if these conditions were adequately managed through appropriate outpatient care, then ED visits should be rare.^4,5 These potentially preventable M/SUD-related ED visits also affect hospitals, because M/SUD-related ED visits are more than twice as likely to result in hospital admission compared with ED visits that do not involve M/SUDs.⁶

This Healthcare Cost and Utilization Project (HCUP) Statistical Brief presents data on trends from 2006 to 2013 in the rate of ED visits involving the following categories of M/SUDs: substance use disorders (SUDs); depression, anxiety or stress reactions; and psychoses or bipolar disorders. These three categories are based on all-listed diagnoses. Analyses were limited to patients aged 15 years and older. Trends in ED visit rates per 100,000 population aged 15 years and older are presented for each type of M/SUD. Change in the rate of ED visits involving M/SUDs over the 7-year period 2006-2013 are presented by patient age, sex, community-level income, hospital region, and patient location of residence. Change in the distribution of ED visits involving M/SUDs between 2006 and 2013 by expected primary payer also is provided. Differences in estimates of 10 percent or greater are noted in the text.

Findings

Trends in M/SUD-related ED visits, 2006-2013
Figure 1 provides trends in the rate of ED visits involving SUDs; depression, anxiety or stress reactions; and psychoses or bipolar disorders per 100,000 population aged 15 years and older, from 2006 to 2013.

• Between 2006 and 2013, the population rate for ED visits involving mental disorders increased faster than the rate for ED visits involving SUDs.
  
  In 2013, the rate of ED visits involving M/SUDs was highest for depression, anxiety or stress reactions at 3,945 per 100,000 population aged 15 years and older, followed by SUDs (2,519 per 100,000 population) and psychoses or bipolar disorders (1,385 per 100,000 population). Between 2006 and 2013, the rate of ED visits increased across M/SUDs, but the increase was higher for mental disorders (55.5 percent for depression, anxiety or stress reactions and 52.0 percent for psychoses and bipolar disorders) than for SUDs (37.0 percent).

Trends in M/SUD-related ED visits by age and sex, 2006-2013
Table 1 provides the rate of ED visits involving SUDs; depression, anxiety or stress reactions; and psychoses or bipolar disorders per 100,000 population aged 15 years and older by patient sex and age group in 2006 and 2013. The cumulative percentage change over the 7-year period also is provided.

• In 2013, the population rate of ED visits involving SUDs was nearly twice as high for males as for females. The rate of ED visits involving mental disorders was either lower for males or similar for both sexes.
  
  The rate of ED visits involving SUDs was nearly twice as high among males (3,346 visits per 100,000 population) as among females (1,733 visits per 100,000 population) in 2013. In contrast, the rate of ED visits involving depression, anxiety or stress reactions was lower among males (2,854 visits per 100,000 population) than among females (4,981 visits per 100,000 population). The rate of ED visits involving psychoses or bipolar disorders was similar for males and females (approximately 1,400 visits per 100,000 population).



• Between 2006 and 2013, the population rate of ED visits involving SUDs increased among all adult age groups but did not increase among teenagers.
  
  For both male and female adults aged 18 years and older, the population rate of ED visits involving SUDs increased between 2006 and 2013 by at least 34.0 percent, depending on the specific age group. In contrast, the rate did not change substantially among either male or female teens aged 15-17 years (-4.7 and -4.1 percent, respectively).
  
  Among males, those aged 45-64 years had the highest rate of ED visits involving SUDs in 2013 (4,377 visits per 100,000 population—2.3 times the rate for females in this age group) and the largest increase in rate (42.2 percent) between 2006 and 2013. Among females, those aged 18-44 years had the highest rate of ED visits involving SUDs in 2013 (2,162 per 100,000 population), but those aged 45-64 years had the largest increase in rate (50.2 percent) between 2006 and 2013.



• Between 2006 and 2013, the population rate of ED visits involving depression, anxiety or stress reactions increased the most among males aged 45-64 years.
  
  For both male and female adults aged 18 years and older, the population rate of ED visits involving depression, anxiety or stress reactions increased between 2006 and 2013 by at least 49.7 percent, depending on the specific age group. The rate also increased among both male and female teens aged 15-17 years, but not as rapidly (25.9 and 33.3 percent, respectively).
  
  Among males, those aged 65 years and older had the highest rate of ED visits involving depression, anxiety or stress reactions in 2013 (3,916 per 100,000 population), but those aged 45-64 years had the largest increase in rate (64.5 percent) between 2006 and 2013. Similarly, among females, those aged 65 years and older had the highest rate of ED visits involving depression, anxiety or stress reactions in 2013 (7,077 per 100,000 population—1.8 times the rate of males in this age group), but those aged 18-44 years and 45-64 years had a larger increase in rate (54.9 and 57.2 percent, respectively) between 2006 and 2013.



• Between 2006 and 2013, the population rate of ED visits involving psychoses or bipolar disorders increased the most among males and females aged 18-44 years and among males aged 45-64 years.
  
  For both male and female adults aged 18-44 years and 45-64 years, the population rate of ED visits involving psychoses or bipolar disorders increased between 2006 and 2013 by at least 53.9 percent, depending on the specific age group. The rate also increased among both males and females aged 15-17 years and 65 years and older, but not as rapidly (maximum 32.8 percent increase).
  
  The rate of ED visits involving psychoses or bipolar disorders in 2013 and the percentage increase in the rate from 2006-2013 were relatively similar between males and females in all age groups. Among males, those aged 18-44 years and 45-64 years had the highest rate of ED visits involving psychoses or bipolar disorders in 2013 (1,419 and 1,527 per 100,000 population, respectively) and the largest increase in rates (56.7 and 59.2 percent, respectively) between 2006 and 2013. Similarly, among females, those aged 18-44 years and 45-64 years had the highest rate of ED visits involving psychoses or bipolar disorders in 2013 (1,522 and 1,552 per 100,000 population, respectively) and the largest increase in rates (61.6 and 53.9 percent, respectively).

Trends in M/SUD-related ED visits by community-level income, hospital region, and patient location, 2006-2013
Between 2006 and 2013, the rate of ED visits per 100,000 population related to SUDs; depression, anxiety or stress reactions; and psychoses or bipolar disorders increased across categories of community-level income, hospital region, and location of patient residence. For each characteristic, the percentage increase in the ED visit rate between 2006 and 2013 is presented for each M/SUD category in Figures 2-4. The ED visit population rates and percentage increases from 2006 to 2013 are presented in Tables 2-4.

• Patients in the lowest income quartiles had larger increases in population rates of M/SUD-related ED visits than did those in the highest income quartiles.
  
  Between 2006 and 2013, the increase in the population rate of ED visits involving SUDs was higher in the lowest income communities (Quartile 1: 40.8 percent) than in the three highest income communities (Quartiles 2-4: range, 32.3-36.0 percent). The increase in the rate of ED visits involving depression, anxiety or stress reactions was higher in the two lowest income communities (Quartile 1: 79.4 percent; Quartile 2: 55.3 percent) than in the two highest income communities (Quartiles 3-4: 39.8 percent). Similarly, the increase in the rate of ED visits involving psychoses or bipolar disorders was higher in the two lowest income communities (Quartile 1: 64.5 percent; Quartile 2: 47.4 percent) than in the two highest income communities (Quartiles 3-4: range, 40.3-41.8 percent).

• The Midwest had the largest increase in the population rate of ED visits involving SUDs, and psychoses or bipolar disorders.
  
  Between 2006 and 2013, the increase in the population rate of ED visits involving SUDs was highest in the Midwest (54.3 percent), followed by the West (42.4 percent), Northeast (35.9 percent), and South (26.4 percent). The increase in the rate of ED visits involving depression, anxiety or stress reactions was highest in the South (61.0 percent), West (58.9 percent), and Midwest (55.0 percent), and lowest in the Northeast (45.3 percent). The increase in the rate of ED visits involving psychoses or bipolar disorders was highest in the Midwest (63.7 percent), followed by the West (57.7 percent), and lowest in the Northeast (48.5 percent) and South (45.6 percent).

• Large metropolitan areas had the largest increase in the population rate of ED visits involving SUDs, but micropolitan areas had the largest increase in the rate of ED visits involving depression, anxiety or stress reactions.
  
  Between 2006 and 2013, the increase in the population rate of ED visits involving SUDs was higher in large metropolitan areas (43.7 percent) than in other locations (range, 27.3-29.8 percent). The increase in the rate of ED visits involving depression, anxiety or stress reactions was highest in micropolitan areas (73.6 percent), followed by noncore areas (65.8 percent), large metropolitan areas (55.9 percent), and then small metropolitan areas (46.0 percent). The increase in the rate of ED visits involving psychoses or bipolar disorders was higher in micropolitan (59.4 percent), large metropolitan (55.9 percent), and noncore (54.7 percent) areas, and lowest in small metropolitan areas (39.4 percent).

Trends in M/SUD-related ED visits by payer, 2006-2013
Figure 5 presents the distribution of ED visits involving SUDs; depression, anxiety or stress reactions; and psychoses or bipolar disorders, by expected primary payer in 2006 and 2013.

• Between 2006 and 2013, the proportion of M/SUD-related ED visits paid by private insurance decreased whereas the proportion paid by Medicaid increased.
  
  For all three types of M/SUDs, the percentage of ED visits with an expected primary payer of private insurance decreased between 2006 and 2013 (range: 14.2 to 18.2 percent decrease) whereas the percentage of ED visits covered by Medicaid increased (range: 14.8 to 20.7 percent increase).

Data Source

The estimates in this Statistical Brief are based upon data from the Healthcare Cost and Utilization Project (HCUP) 2006-2013 Nationwide Emergency Department Sample (NEDS). Supplemental sources included population denominators based on data obtained from the Nielsen Company.⁷

Definitions

Diagnoses, ICD-9-CM
The principal diagnosis is that condition established after study to be chiefly responsible for the patient's admission to the hospital. Secondary diagnoses are concomitant conditions that coexist at the time of admission or develop during the stay. All-listed diagnoses include the principal diagnosis plus these additional secondary conditions.

ICD-9-CM is the International Classification of Diseases, Ninth Revision, Clinical Modification, which assigns numeric codes to diagnoses. There are approximately 14,000 ICD-9-CM diagnosis codes.

Case definition
The mental and substance use disorders (M/SUDs) in this Statistical Brief were defined using all-listed ICD-9-CM diagnosis codes and external cause of injury codes (E codes). The specific ICD-9-CM and E codes used for the inclusion and exclusion criteria for each of the three types of M/SUDs are provided in the separate appendix associated with this Statistical Brief on the HCUP-US website at http://www.hcup-us.ahrq.gov/reports/statbriefs/sb216-appendix.pdf.

Categories for M/SUDs used in this Statistical Brief were conceptualized and reviewed in 2013 by a workgroup of 15 invited experts with expertise in medicine, behavioral health, community health, measurement, and data. The workgroup was tasked with reviewing, evaluating, and providing feedback on initial development work for Prevention Quality Indicators (PQIs) adapted for the emergency department (ED) setting. The two mental disorder categories used in this Statistical Brief are mutually exclusive, but an ED visit record containing diagnoses for both substances use and mental disorders can be counted in both the SUD category and one of the two mental disorder categories. Psychoses and bipolar disorders were categorized together because these diagnoses represent illnesses that are typically more severe and persistent, particularly among patients who present to EDs. These diagnoses may not be recorded first on a record and are usually noted only if they are an important component of the ED visit. Some physicians may code acute psychoses even when chronic disease is suspected, because of the difficulty of confirming chronic diagnoses in the ED setting.

Types of hospitals included in the HCUP Nationwide Emergency Department Sample
The Nationwide Emergency Department Sample (NEDS) is based on data from community hospitals, which are defined as short-term, non-Federal, general, and other hospitals, excluding hospital units of other institutions (e.g., prisons). The NEDS includes specialty, pediatric, public, and academic medical hospitals. Excluded are long-term care facilities such as rehabilitation, psychiatric, and alcoholism and chemical dependency hospitals. Hospitals included in the NEDS have hospital-owned emergency departments and no more than 90 percent of their ED visits resulting in admission.

Unit of analysis
The unit of analysis is the ED encounter, not a person or patient. This means that a person who is seen in the ED multiple times in 1 year will be counted each time as a separate encounter in the ED.

Location of patients' residence
For the purpose of this Statistical Brief we define the urban-rural designation using Urban Influence Codes (UICs). UICs emphasize the relationship of outlying counties to major metropolitan areas. UICs were developed at the U.S. Department of Agriculture's Economic Research Service as a refinement of the Office of Management and Budget Metropolitan Statistical Area definition.⁸ The four urban-rural designations are as follows:

• Large metropolitan areas with at least 1 million residents
• Small metropolitan areas with fewer than 1 million residents
• Micropolitan areas with cities of at least 10,000 residents
• Areas that are neither metropolitan nor micropolitan (cities with fewer than 10,000 residents)

Median community-level income
Median community-level income is the median household income of the patient's ZIP Code of residence. Income levels are separated into population-based quartiles with cut-offs determined using ZIP Code demographic data obtained from the Nielsen Company. The income quartile is missing for patients who are homeless or foreign.

Payer
Payer is the expected payer for the hospital stay. To make coding uniform across all HCUP data sources, payer combines detailed categories into general groups:

• Medicare: includes patients covered by fee-for-service and managed care Medicare
• Medicaid: includes patients covered by fee-for-service and managed care Medicaid
• Private Insurance: includes Blue Cross, commercial carriers, and private health maintenance organizations (HMOs) and preferred provider organizations (PPOs)
• Uninsured: includes an insurance status of self-pay and no charge
• Other: includes Workers' Compensation, TRICARE/CHAMPUS, CHAMPVA, Title V, and other government programs

Hospital stays billed to the State Children's Health Insurance Program (SCHIP) may be classified as Medicaid, Private Insurance, or Other, depending on the structure of the State program. Because most State data do not identify patients in SCHIP specifically, it is not possible to present this information separately.

For this Statistical Brief, when more than one payer is listed for an ED visit, the first-listed payer is used.

About HCUP

The Healthcare Cost and Utilization Project (HCUP, pronounced "H-Cup") is a family of healthcare 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 (HCUP Partners) and the Federal government to create a national information resource of encounter-level healthcare data. HCUP includes the largest collection of longitudinal hospital care data in the United States, with all-payer, encounter-level information beginning in 1988. These databases enable research on a broad range of health policy issues, including cost and quality of health services, medical practice patterns, access to healthcare programs, and outcomes of treatments at the national, State, and local market levels.

HCUP would not be possible without the contributions of the following data collection Partners from across the United States:

Alaska State Hospital and Nursing Home Association
Arizona Department of Health Services
Arkansas Department of Health
California Office of Statewide Health Planning and Development
Colorado Hospital Association
Connecticut Hospital Association
District of Columbia Hospital Association
Florida Agency for Health Care Administration
Georgia Hospital Association
Hawaii Health Information Corporation
Illinois Department of Public Health
Indiana Hospital Association
Iowa Hospital Association
Kansas Hospital Association
Kentucky Cabinet for Health and Family Services
Louisiana Department of Health and Hospitals
Maine Health Data Organization
Maryland Health Services Cost Review Commission
Massachusetts Center for Health Information and Analysis
Michigan Health & Hospital Association
Minnesota Hospital Association
Mississippi Department of Health
Missouri Hospital Industry Data Institute
Montana MHA - An Association of Montana Health Care Providers
Nebraska Hospital Association
Nevada Department of Health and Human Services
New Hampshire Department of Health & Human Services
New Jersey Department of Health
New Mexico Department of Health
New York State Department of Health
North Carolina Department of Health and Human Services
North Dakota (data provided by the Minnesota Hospital Association)
Ohio Hospital Association
Oklahoma State Department of Health
Oregon Association of Hospitals and Health Systems
Oregon Office of Health Analytics
Pennsylvania Health Care Cost Containment Council
Rhode Island Department of Health
South Carolina Revenue and Fiscal Affairs Office
South Dakota Association of Healthcare Organizations
Tennessee Hospital Association
Texas Department of State Health Services
Utah Department of Health
Vermont Association of Hospitals and Health Systems
Virginia Health Information
Washington State Department of Health
West Virginia Health Care Authority
Wisconsin Department of Health Services
Wyoming Hospital Association

About Statistical Briefs

HCUP Statistical Briefs are descriptive summary reports presenting statistics on hospital inpatient, ambulatory surgery, and emergency department use and costs, quality of care, access to care, medical conditions, procedures, patient populations, and other topics. The reports use HCUP administrative healthcare data.

About the NEDS

The HCUP Nationwide Emergency Department Database (NEDS) is a unique and powerful database that yields national estimates of emergency department (ED) visits. The NEDS was constructed using records from both the HCUP State Emergency Department Databases (SEDD) and the State Inpatient Databases (SID). The SEDD capture information on ED visits that do not result in an admission (i.e., treat-and-release visits and transfers to another hospital); the SID contain information on patients initially seen in the ED and then admitted to the same hospital. The NEDS was created to enable analyses of ED utilization patterns and support public health professionals, administrators, policymakers, and clinicians in their decision-making regarding this critical source of care. The NEDS is produced annually beginning in 2006. Over time, the sampling frame for the NEDS has changed; thus, the number of States contributing to the NEDS varies from year to year. The NEDS is intended for national estimates only; no State-level estimates can be produced.

For More Information

For other information on M/SUDs, refer to the HCUP Statistical Briefs located at http://www.hcup-us.ahrq.gov/reports/statbriefs/sb_mhsa.jsp.

For additional HCUP statistics, visit:

• HCUP Fast Stats at https://datatools.ahrq.gov/hcup-fast-stats for easy access to the latest HCUP-based statistics for health information topics
• HCUPnet, HCUP's interactive query system, at https://datatools.ahrq.gov/hcupnet

For more information about HCUP, visit http://www.hcup-us.ahrq.gov/.

For a detailed description of HCUP and more information on the design of the Nationwide Emergency Department Sample (NEDS), please refer to the following database documentation:

Agency for Healthcare Research and Quality. Overview of the Nationwide Emergency Department Sample (NEDS). Healthcare Cost and Utilization Project (HCUP). Rockville, MD: Agency for Healthcare Research and Quality. Updated January 2016. http://www.hcup-us.ahrq.gov/nedsoverview.jsp. Accessed February 17, 2016.

Suggested Citation

Weiss AJ (Truven Health Analytics), Barrett ML (M.L. Barrett, Inc.), Heslin KC (AHRQ), Stocks C (AHRQ). Trends in Emergency Department Visits Involving Mental and Substance Use Disorders, 2006-2013. HCUP Statistical Brief #216. December 2016. Agency for Healthcare Research and Quality, Rockville, MD. http://www.hcup-us.ahrq.gov/reports/statbriefs/sb216-Mental-Substance-Use-Disorder-ED-Visit-Trends.pdf.

Acknowledgments

The authors would like to acknowledge the contributions of Minya Sheng and Emma Mollenhauer of Truven Health Analytics.

***

AHRQ welcomes questions and comments from readers of this publication who are interested in obtaining more information about access, cost, use, financing, and quality of healthcare in the United States. We also invite you to tell us how you are using this Statistical Brief and other HCUP data and tools, and to share suggestions on how HCUP products might be enhanced to further meet your needs. Please e-mail us at hcup@ahrq.gov or send a letter to the address below:

David Knutson, Director
Center for Delivery, Organization, and Markets
Agency for Healthcare Research and Quality
5600 Fishers Lane
Rockville, MD 20857


This Statistical Brief was posted online on December 6, 2016.


¹ National Institute of Mental Health. Any Mental Illness (AMI) Among U.S. Adults. https://www.nimh.nih.gov/health/statistics/prevalence/any-mental-illness-ami-among-us-adults.shtml. Accessed October 21, 2016.
² Owens PL, Mutter R, Stocks C. Mental Health and Substance Abuse-Related Emergency Department Visits Among Adults, 2007. HCUP Statistical Brief #92. July 2010. U.S. Agency for Healthcare Research and Quality, Rockville, MD. http://www.hcup-us.ahrq.gov/reports/statbriefs/sb92.pdf. Accessed June 28, 2016.
³ Agency for Healthcare Research and Quality. Chartbook on Care Coordination. Measures of Care Coordination: Preventable Emergency Department Visits. May 2015. Rockville, MD: Agency for Healthcare Research and Quality. https://www.ahrq.gov/research/findings/nhqrdr/chartbooks/carecoordination/index.html. Accessed June 4, 2020.
⁴ Rockett IRH, Putnam SL, Jia H, Chang C, Smith GS. Unmet substance abuse treatment need, health services utilization, and cost: a population-based emergency department study. Annals of Emergency Medicine. 2005;45(2):118-27.
⁵ Yoon J, Yano EM, Altman L, Coradsco KM, Stockdale SE, Chow A, et al. Reducing costs of acute care for ambulatory care-sensitive medical conditions: the central roles of comorbid mental illness. Medical Care. 2012;50(8):705-13.
⁶ Owens et al., 2010. Op. cit.
⁷ The Nielsen Company. Nielsen Demographic Data. https://www.claritas.com. . Accessed November 8, 2017.
⁸ Additional information about the UIC classification scheme is available at U.S. Department of Agriculture, Economic Research Service. Urban Influence Codes. Updated October 12, 2016. http://www.ers.usda.gov/data-products/urban-influence-codes.aspx. Accessed November 4, 2016.