User Support

March 2013

Zeynal Karaca, Ph.D., Herbert S. Wong, Ph.D., and Ryan L. Mutter, Ph.D.



Introduction

Addressing the multidimensional health problems of homeless people is a challenge for public policymakers and healthcare providers. According to the National Coalition for the Homeless, approximately 3.5 million individuals in the United States are likely to experience homelessness in a given year.¹ Based on the 2009 Homeless Annual Assessment Report to Congress,² about 1.56 million people used an emergency shelter or a transitional housing program between October 1, 2008, and September 30, 2009.

Prior studies have shown that homeless people have poorer health status; higher rates of physical illness, mental illness, and substance abuse; and earlier mortality when compared to the general public.^3,4 The prevalence of these health problems among homeless people varies across age cohorts (i.e., infectious disease, substance use, and mental illness are observed more frequently among younger homeless people).⁵ The fact that homeless people have limited access to healthcare,^6-10 which leads to delayed clinical presentation,¹¹ increased reliance on emergency departments,¹² and higher rates of hospitalization¹³ —often for preventable conditions¹⁴—is well documented.

Prior research has also shown that homeless people have higher rates of emergency department visits than the general public and are among the most frequent repeat visitors.^15,16 Prevalence of both acute and chronic conditions is higher among homeless people^17-22 who are more likely to be admitted to hospitals¹³ and have longer stays.¹⁴ More frequent admissions to hospitals, coupled with longer stays, have resulted in substantial burden on the resources of hospitals and emergency departments.^23-25 Prior research has further shown that the insurance status of homeless people has an effect on their seeking non-urgent medical care, on having a regular site of care that is not the emergency department, and on receiving inpatient treatment for mental disorders.^26-28

This Statistical Brief compares patient characteristics, insurance coverage, and conditions treated during inpatient hospital stays and treat-and-release (T&R) emergency department (ED) visits by racial/ethnic groups for homeless and non-homeless patients. This analysis focuses on use of healthcare services by homeless patients regardless of where they receive care. We explored the ratio of visits admitted to inpatient facilities from EDs both in the aggregate and for specific racial/ethnic groups among homeless and non-homeless patients. This ratio may be an indicator of differences in severity of illness among patients seen in the ED.

Finally, for the highest frequency disease category—mental disorders—we compared frequencies of specific mental conditions for homeless and non-homeless patients in the aggregate and by racial/ethnic group.

Findings

There were 177,056 hospital inpatient stays by homeless patients during 2008 in the ten states used in this analysis that record homelessness on the discharge record: Arizona, California, Colorado, Florida, Georgia, Massachusetts, Missouri, New York, Pennsylvania, and Wisconsin. Similarly, there were 49,595 T&R ED visits by homeless patients during 2008 in seven of these states that collect ED data: Arizona, Florida, Georgia, Massachusetts, Missouri, New York, and Wisconsin.

Inpatient hospital use

Race/Ethnicity
Table 1 presents selected characteristics of hospitalized homeless patients and non-homeless patients. Among homeless patients admitted to the hospital, 19.5 percent were White, 33.2 percent were Black, and 15.1 percent were Hispanic. On the other hand, 63.6 percent of non-homeless hospitalized patients were White, 13.1 percent were Black, and 14.5 percent were Hispanic. These results suggest that 2.8 percent (= 58,805 ÷ (58,805+2,073,616)) of inpatient stays by Black patients were linked to homelessness, compared to only 0.3 percent of White and 1.2 percent of Hispanic patients.

Age
Table 1 shows that 16.1 percent of hospital stays by homeless patients were for children under 15 years old, compared to 15.2 percent of stays by non-homeless children. A larger discrepancy was found among the elderly—14.1 percent of hospital stays by homeless patients were for people over 64 years old, compared to 34.3 percent of stays by non-homeless elderly patients.

Homelessness was more prevalent among younger Black and Hispanic patients. The proportion of homeless children under 15 years old among Blacks (15.7 percent) and Hispanics (19.4 percent) was at least 5 times higher than the proportion of White homeless children (2.7 percent) of the same age cohort. Likewise, hospital stays among homeless patients under 25 years old who were Black or Hispanic were substantially higher (26.8 and 32.0 percent, respectively), compared to White homeless patients (8.2 percent). Similarly, the proportions of hospitalized homeless White, Black, and Hispanic patients between 25 and 64 years old were 75.5, 61.2, and 55.9 percent, respectively—higher than their non-homeless counterparts: 41.4, 51.8, and 42.3 percent. Only for patients older than 74 years was homelessness more prevalent among White patients (10.1 percent) compared to Blacks (6.0 percent) and Hispanics (5.8 percent).

Gender
Table 1 also shows that among homeless patients, females constituted only about a third of hospital stays among White patients, while females constituted over half of visits among other race/ethnicity groups (52 percent). For non-homeless patients at inpatient facilities, the proportion of stays by female patients was between 57 and 61 percent across all race/ethnicity groups.

Insurance coverage
Table 1 reveals a sizable discrepancy in expected primary payer between homeless and non-homeless patients. Over one in four (28.1 percent) hospitalized homeless patients were uninsured. The proportion of uninsured homeless patients was over 6 times higher (= 28.1% ÷ 4.6%) than the proportion among their non-homeless counterparts.

The ratios of uninsured homeless patients to uninsured non-homeless patients were 5.3 for Whites, 3.3 for Blacks, and 6.2 for Hispanics, revealing that lack of insurance coverage for homeless patients was highest among Hispanics admitted to the hospital and lowest among Black patients when compared to their non-homeless counterparts.

Most insurance coverage for homeless patients was provided by Medicaid (48.2 percent), and Medicare was the expected payer for 17.1 percent. Only a small portion of homeless individuals had private insurance (2 percent). Medicare was the leading source of coverage for non-homeless patients (37.0 percent), followed by private insurance (33.8 percent) and Medicaid (21.0 percent).

The ratio of Medicaid coverage for all homeless patients to all non-homeless patients was 2.3 (= 48.2% ÷ 21.0%), which implies that homeless patients are more than twice as likely to be covered by Medicaid than are non-homeless patients. However, the ratios of Medicaid coverage for homeless White, Black, and Hispanic groups when compared to their non-homeless counterparts were 3.1, 1.6, and 0.9, respectively. This indicates that, among those who were admitted to the hospital, non-homeless Blacks and Hispanics relative to homeless Blacks and Hispanics were more likely to be covered by Medicaid.

Admission from the ED and disease prevalence
Table 2 presents the selected clinical characteristics of hospitalized homeless patients and non-homeless patients. The table shows that 73.7 percent of hospital admissions for homeless originated in EDs, compared to 50.6 percent of admissions for non-homeless patients. The relative racial compositions of homeless and non-homeless patient populations admitted through the ED were relatively similar.

Table 2 shows that the prevalence of various diseases treated in the hospital was generally similar between homeless and non-homeless patients for the majority of disease categories, except for mental disorders and diseases of the circulatory system. The proportion of hospitalized homeless patients with mental disorders (22.4 percent of all homeless patients) was about 3.4 times higher than their non-homeless counterparts (6.6 percent).

There were also racial/ethnic differences among homeless and non-homeless patients hospitalized for mental disorders. Forty-three percent of White homeless patients had a mental illness principal diagnosis, compared to only 6.8 percent of white non-homeless patients—6.3 times higher among homeless patients. Among blacks, homeless patients had 2.8 times higher prevalence of mental disorder principal diagnoses than non-homeless patients. Among Hispanics, homeless patients had 3.9 times higher prevalence of mental disorders than non-homeless patients.

Mental disorders subcategories
Table 3 presents details on specific types of mental disorders and shows that 33.8 percent of hospital stays by homeless individuals with mental disorders were related to schizophrenia and other psychotic disorders, followed by mood disorders (24.7 percent), alcohol-related disorders

(20.6 percent), and substance-related disorders (13.5 percent). As shown in Figure 1, the prevalence of hospital stays due to mood disorders was highest among White homeless patients and the prevalence of stays due to schizophrenia and other psychotic disorders was substantially higher among Black patients than among Whites and Hispanics.

Use of hospital-affiliated EDs

Race/Ethnicity
Table 4 presents descriptive statistics of T&R ED visits by homeless and non-homeless patients at hospital-affiliated EDs. Overall, Whites constituted 60.2 percent of ED visits for homeless patients, Blacks constituted 22.5 percent, and Hispanics 10.6 percent. These proportions are similar for non-homeless patients: 57.1 percent White, 21.7 percent Black, and 12.3 percent Hispanic.

Age
Table 4 shows that only 2.9 percent of T&R ED visits by homeless patients were for those under 15 years old—substantially lower than for their non-homeless counterparts (25.9 percent). The majority of T&R ED visits by homeless patients were made by individuals 25–44 years old (39.0 percent) and 45–64 years old (45.9 percent), compared to 20.8 and 20.0 percent for non-homeless patients, respectively.

There was little age discrepancy across race/ethnicity groups between homeless and non-homeless patients; however, Hispanic children had relatively higher numbers of ED visits compared to White and Black children. Six percent of all ED visits by homeless Hispanic patients were for children under the age of 15—3 to 4 times higher than for White (1.9 percent) and Black (1.5 percent) homeless children. Among ED visits for non-homeless patients, 32.4 percent were for Hispanic children under age 15, 16.5 percent were for White children, and 22.9 percent were for Black children.

Gender
One out of four T&R ED visits by homeless patients was made by females compared with about 1 out of 2 visits by non-homeless patients. This was similar across race/ethnicity groups.

Insurance coverage
Table 4 shows a sizable discrepancy in payer status between homeless and non-homeless patients. Overall, the proportion of T&R ED visits by uninsured homeless patients (42.8 percent) was 2.2 times higher than for their non-homeless counterparts (19.9 percent). The lack of insurance coverage for homeless patients was lowest among Black patients when compared to their non-homeless counterparts.

Most coverage for homeless patients was provided by Medicaid (34.7 percent), followed by Medicare (12.4 percent) and private insurance (5.7 percent). Private insurance provided coverage for 38.3 percent of visits by non-homeless patients, followed by Medicaid (22.5 percent) and Medicare (13.8 percent).

Disease prevalence
Table 5 shows that nearly half of all T&R ED visits by homeless patients involved a mental illness diagnosis (49.0 percent). This was 3.5 times higher than their non-homeless counterparts (14.0 percent).

A similar pattern was evident by race/ethnicity. While there were some discrepancies between homeless and non-homeless patients in the prevalence of other conditions recorded during T&R ED visits, the magnitude of the differences was relatively small compared to mental disorders. The results presented in Table 3 show that alcohol-related disorders was the most common mental condition noted during ED visits for the homeless (52.8 percent), followed by screening and history of mental health and substance abuse (29.7 percent), mood disorders (21.1 percent), and substance-related disorders (17.6 percent).

As shown in Figure 2, the prevalence of alcohol-related disorders was higher among Hispanic homeless patients. Similarly, Black homeless patients had relatively higher ED encounters for schizophrenia and other psychotic disorders.

Data Source

The estimates in this Statistical Brief are based upon data from the Healthcare Cost and Utilization Project (HCUP) State Inpatient Databases (SID) and State Emergency Department Databases (SEDD) for 2008. The SID employed in this study include data on 15,811,363 inpatient stays—of which 177,056 are for homeless patients—from inpatient hospitals in 10 geographically dispersed states (Arizona, California, Colorado, Florida, Georgia, Massachusetts, Missouri, New York, Pennsylvania, and Wisconsin). The SEDD include data on 23,710,754 treat-and-release emergency department (T&R ED) visits—of which 49,595 are for homeless patients—from hospital-affiliated emergency departments in seven geographically dispersed states (Arizona, Florida, Georgia, Massachusetts, Missouri, New York, and Wisconsin).

Definitions

Diagnoses, ICD-9-CM, and Clinical Classifications Software (CCS)
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.

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.

CCS categorizes ICD-9-CM diagnoses into a manageable number of clinically meaningful categories.²⁹ This "clinical grouper" makes it easier to quickly understand patterns of diagnoses. CCS categories identified as "Other" typically are not reported; these categories include miscellaneous, otherwise unclassifiable diagnoses that may be difficult to interpret as a group.

Case definition
Homelessness is directly reported by the hospitals. There is an indicator for each discharge from inpatient hospitals or hospital-affiliated EDs regarding patient's homelessness status.

Types of hospitals included in HCUP
This analysis is based on the data that includes all discharges reported by all hospitals including mental health facilities in HCUP SID for Arizona, California, Colorado, Florida, Georgia, Massachusetts, Missouri, New York, Pennsylvania, and Wisconsin; and HCUP SEDD for Arizona, Florida, Georgia, Massachusetts, Missouri, New York, and Wisconsin during 2008.

Unit of analysis
HCUP SID and SEDD data are based on encounters as the unit of analysis, so a given patient may have many encounters. As a consequence, the summary information reported under patient characteristics might overestimate or underestimate demographics for individual patients.

In addition, it is difficult to differentiate between the principal diagnosis codes and other diagnosis codes in emergency department settings. Therefore, we used all diagnosis codes reported for each visit when developing our disease categories.

Payer
Payer is the expected primary 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. Patients covered by the State Children's Health Insurance Program (SCHIP) may be included here. Because most State data do not identify SCHIP patients specifically, it is not possible to present this information separately.
• Private Insurance: includes Blue Cross, commercial carriers, and private health maintenance organizations (HMOs) and preferred provider organizations (PPOs)
• Other: includes Worker's Compensation, TRICARE/CHAMPUS, CHAMPVA, Title V, and other government programs
• Uninsured: includes an insurance status of "self-pay" and "no charge."

When more than one payer is listed for a hospital discharge, the first-listed payer is used.

Admission source or point of origin
Admission source (now known as patient's point of origin) indicates where the patient was located prior to admission to the hospital. Emergency admission indicates that the patient was admitted to the hospital through the emergency department. Admission from another hospital indicates that the patient was admitted to this hospital from another short-term, acute-care hospital. This usually signifies that the patient required the transfer in order to obtain more specialized services that the originating hospital could not provide. Admission from a long-term care facility indicates that the patient was admitted from a long-term facility such as a nursing home.

Reporting of race and ethnicity
HCUP SID for Arizona, California, Colorado, Florida, Georgia, Massachusetts, Missouri, New York, Pennsylvania, and Wisconsin; and HCUP SEDD for Arizona, Florida, Georgia, Massachusetts, Missouri, New York, and Wisconsin report race and ethnicity. This Statistical Brief reports the HCUP uniform coding of race/ethnicity for the following categories: White, Black, and Hispanic.

About HCUP

HCUP is a family of powerful healthcare databases, software tools, and products for advancing research. Sponsored by the Agency for Healthcare Research and Quality (AHRQ), HCUP includes the largest all-payer encounter-level collection of longitudinal healthcare data (inpatient, ambulatory surgery, and emergency department) in the United States, beginning in 1988. HCUP is a Federal-State-Industry Partnership that brings together the data collection efforts of many organizations—such as State data organizations, hospital associations, private data organizations, and the Federal government—to create a national information resource.

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
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 Health Policy and Research
Pennsylvania Health Care Cost Containment Council
Rhode Island Department of Health
South Carolina Budget & Control Board
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 the SID

The HCUP State Inpatient Databases (SID) are hospital inpatient databases from data organizations participating in HCUP. The SID contain the universe of the inpatient discharge abstracts in the participating HCUP States, translated into a uniform format to facilitate multistate comparisons and analyses. Together, the SID encompass more than 95 percent of all U.S. community hospital discharges in 2008. The SID can be used to investigate questions unique to one State; to compare data from two or more States; to conduct market area variation analyses, and to identify State-specific trends in inpatient care utilization, access, charges, and outcomes.

About the SEDD

The HCUP State Emergency Department Databases (SEDD) are a powerful set of databases, from data organizations in participating States, that capture discharge information on all emergency department visits that do not result in an admission. The SEDD combined with SID discharges that originate in the emergency department are well suited for research that requires complete enumeration of hospital-affiliated emergency departments within market areas or States. Researchers and policymakers use the SEDD to conduct market area research or small area variation analyses, identify patterns of care for patients with various demographic and clinical characteristics, and examine State-specific trends in emergency department utilization, access, charges, and outcomes.

For More Information

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

For additional HCUP statistics, visit HCUPnet, our interactive query system, at https://datatools.ahrq.gov/hcupnet.

For information on other hospitalizations in the United States, download HCUP Facts and Figures: Statistics on Hospital-Based Care in the United States in 2009, located at http://www.hcup-us.ahrq.gov/reports.jsp.

Introduction to the HCUP State Inpatient Databases. Online. September 2011. U.S. Agency for Healthcare Research and Quality. Available at http://hcup-us.ahrq.gov/db/state/siddist/Introduction_to_SID.pdf. (Accessed January 29, 2013).

Introduction to the HCUP State Emergency Department Databases. September 2011. U.S. Agency for Healthcare Research and Quality. Available at http://hcup-us.ahrq.gov/db/state/sedddist/Introduction_to_SEDD.pdf. (Accessed January 29, 2013).

Suggested Citation

Karaca Z (AHRQ), Wong H (AHRQ), Mutter R (AHRQ). Characteristics of Homeless and Non-Homeless Individuals Using Inpatient and Emergency Department Services, 2008. HCUP Statistical Brief #152. March 2013. Agency for Healthcare Research and Quality, Rockville, MD.. Agency for Healthcare Research and Quality, Rockville, MD. Available at http://www.hcup-us.ahrq.gov/reports/statbriefs/sb152.pdf.

Acknowledgements

The authors would like to acknowledge the contributions of Janette Walters of Social & Scientific Systems, Inc.

***

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:

Irene Fraser, Ph.D., Director
Center for Delivery, Organization, and Markets
Agency for Healthcare Research and Quality
540 Gaither Road
Rockville, MD 20850



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