Utilization & Costs of Medical Services by Homeless Persons:

Abstract

April 1999

by James J. O'Connell, M.D.

Boston Health Care for the Homeless Program
729 Massachusetts Avenue
Boston, MA 02118

Homeless persons live in abject poverty without the security of stable homes, and may constitute a population with higher health care costs. The lack of accessible primary care and the severity and co-morbidity of medical and psychiatric illness in this population is likely to result in increased utilization of emergency departments and more frequent acute care hospital admissions. However, a dearth of data has rendered their patterns of disease, health care utilization, and subsequent costs to the health care system largely unknown.

This paper reviews the current literature concerning the patterns of disease, utilization, and costs of medical care services by homeless individuals, with particular emphasis on the accepted markers of acute hospital admissions and the use of emergency departments.

I. Background

Western history and literature are replete with the ills and misfortunes that have plagued the homeless poor. The sanctuary of Medieval cathedrals and churches, the almshouses of the Middle Ages, the lodging houses of Orwellian England,¹ and the burgeoning shelters of the American urban landscape during the past two decades have given witness to the burden of illness carried by those wandering homeless on the fringes of society. Malnutrition, poor sanitation, overcrowding in poorly-ventilated dormitory-style buildings, repeated exposures to the extremes of weather and temperature, the habitual use of alcohol and drugs, the relentless torment of intrusive voices and hallucinations, and inadequate access to primary and preventive health care only begin the litany of risks faced by those struggling to survive on the streets and in the shelters.

Despite an emerging and impressive body of literature on homelessness, a striking paucity of data exists on the utilization of medical care services by homeless persons and the subsequent costs of this population to the health care system. Several reasons can be surmised, including the exasperating difficulty in defining "the homeless." Indeed, homelessness is a complex social phenomenon that thwarts simple definition, a murky chasm beneath the safety net known to a heterogeneous cross-section of society's most vulnerable persons: families with children, runaway and throwaway adolescents, and adult men and women from youth to very old age. Opportunity and choice are limited not only by abject and persistent poverty, but also the challenges of chronic mental illness, substance abuse, physical and sexual violence, illiteracy, complex acute and chronic medical problems, the nightmares of recent and remote wars, or advancing years with meager financial reserves and atrophied gray matter. Extreme poverty and a lack of housing are perhaps the only shared characteristics of this eclectic population, and the complexity of need and rich diversity of the homeless have confounded and bewildered researchers.

The corollary to an imprecise definition has been an elusive denominator. No research methodology has been able to accurately enumerate the homeless. Estimating the size of this population in the United States and in any particular city has been contentious and problematic, hampered by the geographic and temporal transience of homeless persons and the logistical difficulties with sampling techniques. Numbers have ranged from 250,000 to 3 million^2,3 on any specific night; some estimate that 13.5 million Americans have experienced "literal" homelessness at some period in their lifetimes.⁴

II. Medical Problems of Homeless Persons

Much has been written about the problems of substance abuse and mental illness among homeless individuals and families. In contrast, studies of the medical problems and patterns of disease among homeless persons have been largely descriptive. Nonetheless a composite emerges of a population suffering disproportionately from a plethora of physical and public health problems.

Common primary care problems are seen frequently by homeless providers, including hypertension, diabetes, peripheral vascular disease, respiratory problems, and chronic liver and renal disease.^5-10

Tuberculosis ¹¹ and HIV/AIDS ^12-14 are endemic in this population and have been well-documented in the literature. Other infectious and communicable diseases have been described, many of which harken to earlier times and are seldom seen by today's clinicians, such as diphtheria,¹⁵ infestations that result in endocarditis and bacteremia from Bartonella quintana (the organism carried by lice that is the cause of trench fever),^16,17 and Haemophilus influenza bacteremia and septic arthritis among adults.¹⁸

Skin diseases are extraordinarily common, and can lead to costly hospital admissions for cellulitis.¹⁹ Foot care is a critical component of the health care of homeless persons; timely podiatry services can avoid limb-threatening and life-threatening infections.²⁰ Hypothermia and frostbite are dreaded hazards of life on the streets and have been shown to be risk factors for early death.²¹ Trauma and violence are more common among homeless poor than the housed poor.²² Poor nutrition among homeless populations causes anemia as well as growth and development problems in children, and exacerbates medical problems in adults.²³

Homeless persons have been shown to have high mortality rates in studies from Atlanta ²⁴ and San Francisco.²⁵ In Philadelphia, the mortality rate in a cohort of homeless adults was 3.5 times that of the general population.²⁶ Hwang and colleagues in Boston found that homeless men aged 18 to 24 years were 5.9 times more likely to die than housed counterparts, and men aged 25 to 44 years three times more likely to die.²⁷

These studies have revealed much about the specific medical and public health problems associated with homelessness. In the following section, we will review what is known about the utilization and costs of health care services by this population.

III. Hospital Admissions

A. Frequency and rates of hospitalization

1. Children

A Glasgow study showed that children from impoverished areas were 9 times as likely to be admitted to hospital as other children in that city.²⁸ Children from homeless families have also been shown to be disproportionately represented among all children admitted to hospital with burns and scalds.²⁹ At St. Mary's Hospital in London, Victor found that the overall admission rate for homeless persons was 4-5 times greater than for housed residents of an inner city health district; the admission rate for homeless children was twice that of housed children.³⁰

Several studies from Great Britain have shown that homelessness is a significant factor in the decision to admit children to acute care hospitalization. A prospective case-controlled study by Lissauer and colleagues in London examined the influence of homelessness on acute pediatric hospital admissions.³¹ All homeless children under the age of 5 who were admitted to the hospital via the emergency department during 1989-1990 were compared with age-matched domiciled children to assess whether homelessness influenced the admitting physician's decision. The physicians were surveyed during the admission regarding mitigating social factors and severity of illness. Lengths of stay were recorded, and subsequent home visits were made to assess social risk factors and to observe the accommodations. During the study period, 70 homeless children were admitted. Social issues influenced the decision to admit in 77% of the homeless and 43% of the controls. The homeless children had a mean length of stay of 3.6 days compared to 4.5 days for the housed children. More homeless children suffered only mild illness (33/70) than housed children (21/70). Thus the authors conclude that social factors were an important influence in the admission of more than three-quarters of the homeless children, and resulted in admissions for milder illnesses than for other poor but housed children.

Three of the homeless children died during hospitalization and none of the controls. The deaths were due to fulminant infections, and question whether the high mortality rate in this small cohort of homeless children reflects increased severity of illness or a lack of primary care. The authors assert that both factors are applicable. More severe illness is seen in impoverished families with considerable social deprivation. Primary care appeared to be less accessible and/or less utilized by the homeless cohort: only 10% of the homeless children had been referred to the hospital by a general practitioner compared with 36% of the controls.

2. Adults

Homeless individuals in Hawaii had higher rates of admissions to acute care medical and psychiatric hospitals than the general population. Martell performed a retrospective chart review to determine hospitalization rates among a subgroup of homeless persons from 1988 to 1990.³² Of a total of 1751 persons, 564 hospitalizations were identified (92 psychiatric admissions to Hawaii State Hospital, and 472 to seven acute care hospitals in Honolulu). The age- and sex-adjusted hospitalization rate for the psychiatric hospital was 106/1000 person-years, over 100 times the state rate of 0.8/1000 person-years. Homeless persons accounted for 3837 days in the psychiatric hospital, compared with a predicted 139 days. The primary diagnoses were: schizophrenia (39%), bipolar disorder (22%), and schizo-affective disorder (12%). The average length of stay for the homeless was significantly shorter than for the non-homeless: 41.7 days compared to 103 days.

The hospitalization rate to acute care hospitals was 542/1000 person-years, over 5 times the state rate of 96/1000 person-years. These admissions accounted for 4766 hospital days compared with a predicted 640 days. The primary causes of admission were: psychiatric illness (23%), trauma (11%), cellulitis (9%), and illness related to substance abuse (8%). The average length of stay for acute care hospitalization was 10.1 days compared to the statewide average of 7.9 days at that time. The costs associated with these hospital admissions are discussed below.

Victor found that homeless families in one health authority in London accounted for 9% of the inpatient beds in the local hospital.³⁰ This inner city district had a large concentration of homeless families because 200 of London's approximately 600 bed-and-breakfast hotels that accommodated homeless families were situated within this district.. The population of the district totaled 124,000 persons; authorities identified 1569 homeless families: 5595 individuals of whom 2787 were children 0-14 years old. St. Mary's Hospital had 1105 total admissions during May 1988, of which 71 were from homeless families living in the hotels. This admission rate was 4 times that of the resident population: 12.8 admissions/1000 person-months compared with 2.8/1000. Homeless children were more than twice as likely to be admitted to the hospital (6.4/1000 compared to 2.9/1000). Victor also examined use of the emergency services, and found that homeless persons were 2.6 times more likely to use the emergency department than the local residents.

Victor's study raises important questions that presage health care for homeless persons under capitated managed care in the USA. Homeless persons do not receive a cost-adjustment from the National Health Service (NHS); in addition, these authors note that many homeless are not registered with the NHS and are thus uninsured. Hospitals such as St. Mary's Hospital in London are located in poor areas with high geographic concentrations of shelters and hotels for homeless persons, and hence will serve disproportionately more homeless persons than other hospitals. Yet the local health authority receives no additional allocation of funds to compensate for the care of homeless persons.

Hospitalization rates and emergency department utilization were higher among homeless persons than housed persons at San Francisco General Hospital. A cross-sectional analysis by Braun and colleagues found 400 adults who used San Francisco General Hospital's Emergency Department during a one-year period (12/92 through 11/93) and who also slept in shelters or ate in free-lunch lines. All patients were interviewed and the medical charts were reviewed. The hospitalization rate for homeless persons was 2.7 times greater than the general population: 368 days per 1000 person-years compared to 136 days per 1000 person-years.³³

The Boston Health Care for the Homeless Program (BHCHP) prospectively followed homeless individuals who utilized the BHCHP Primary Care Clinic at Boston Medical Center during two successive years, July 1995 through June 1996 and July 1996 through June 1997. All admissions to this former municipal hospital were tracked. The hospitalization rates were strikingly similar for each year of the two-year study period: 2815 hospital days per 1000 person years. These utilization rates are from a single inner city hospital and are likely to underestimate the true use of acute care hospitals because admissions by this homeless cohort to other hospitals in Boston and the Commonwealth were not captured in this study.³⁴

Weinreb and colleagues found that the rate of hospitalization for homeless mothers was four times that of low-income housed women in Worcester, Massachusetts. The health characteristics and service utilization patterns were compared in a case-control study of 220 homeless and 216 low-income housed mothers. In addition to more frequent hospitalizations, the homeless mothers had more emergency department visits and engaged in more high-risk behaviors than their housed counterparts. This study was performed in a medium-sized city, and involved more Hispanic and fewer African-American women than is characteristic of larger urban cities.³⁵

A 1995 national survey of Veterans Affairs medical centers and domiciliary programs found that homeless veterans were 7 times more likely to be hospitalized as other low-income veterans.³⁶

Winkleby and colleagues in San Jose, California, performed a cross-sectional survey of 1437 homeless adults and 3122 non-homeless adults in that area. While the study concentrated on the pre-homeless prevalences of alcohol abuse, illegal drug use, and psychiatric hospitalization, the authors found that homeless men were 4.6 times more likely to have been hospitalized for psychiatric care than housed residents of San Jose, while homeless women were 5.9 times more likely to have been admitted to the hospital for psychiatric care.³⁷

The Boston Health Care for the Homeless Program collaborated with the Massachusetts Rate Setting Commission in an effort to understand the population-based statewide hospitalization rate for a large cohort of homeless individuals who received primary and episodic care within BHCHP's citywide network. Beginning in 1994, the Rate Setting Commission maintained a database of all Massachusetts hospitalizations, including both the insured and uninsured. During calendar year 1994, BHCHP provided medical services for 5926 homeless adults aged 18 and over in the program's two hospital-based primary care clinics and the 45 shelter and outreach clinics in the greater Boston area. From those records, 3962 unique social security numbers were available. Of the 3962 identifiable homeless persons seen by BHCHP, 1498 individuals had been admitted to acute care medical or psychiatric hospitals for a total of 4055 admissions from January 30, 1994 through September 30, 1995.³⁸ Further analysis of this data is currently underway, but the rather sobering result is that BHCHP must be prepared for an average of one acute care hospitalization per enrolled adult patient per year. Such preliminary data has potentially profound implications for the ability of managed care plans to provide care for homeless persons without data and strategies for identification of enrolled homeless persons as a high-risk group that requires accurate risk-adjustment.

B. Prevalence of Homelessness Among Hospitalized Persons

Several studies have examined cohorts of hospitalized patients to determine the prevalence of homelessness. In these selected populations, from 5% to 46% of the inpatients have been homeless.

Bindman retrospectively reviewed the hospital records of 4,263 indigent patients admitted in 1985 and 1986 in San Diego County and found 226 (5.3%) to be homeless. Skin diseases as a discharge category was more common among the homeless (21.2%) than the housed cohort (8.7%), and cellulitis was the most frequent diagnosis-related group (DRG) within this category. "Substance use and substance-induced organic mental disorders" were also more common among the homeless.³⁹

Homeless persons accounted for 8% of acute admissions in two district health authorities in inner city London in 1990. In March 1990, London had an estimated 60,000 homeless people, including over 55,000 in temporary accommodations, 3,295 hostel dwellers, and 651 living on the streets. Homeless persons accounted for 105 of the 1256 acute admissions to two health authorities in November 1990. Black and his colleagues estimated that homeless persons would account for 7,598 admissions to acute care hospitals in London each year.⁴⁰

In the study noted above, Victor and colleagues found that homeless families living in hostels in London were responsible for 9% of admissions to the local district hospital.³⁰

Fifteen percent of persons admitted and diagnosed with deliberate self-harm in an inner city London hospital were homeless and "of no fixed abode". Cullum studied the demographics of all patients who presented with suicide attempts over a three-year period, and concluded that deliberate self harm is common among homeless persons in inner city hospitals and that homeless persons are at greater risk of suicide.⁴¹

In unpublished data, O'Connell and Lebow prospectively reviewed admissions to one of the four medical teams at Boston City Hospital during September and November of 1993. Homeless persons living on the streets, in shelters, or in transitional programs comprised 24% of the admissions in September, and 28% of the admissions in November. A comparison month at Massachusetts General Hospital during December 1993 found that homeless persons accounted for 12% of the admissions to the ward medical service.

Herman found that 46% of patients with dual diagnosis admitted to a large New York psychiatric hospital were homeless at the time of admission. No significant differences in diagnoses were noted between the domiciled and homeless patients.⁴²

Marcos evaluated a New York City program to serve homeless persons with severe mental illness, and found that almost all participants had been previously hospitalized for psychiatric care.⁴³ This program provided outreach services to severely disturbed individuals living in parks and on the streets, and offered admission to a public hospital. During the first year of this program, 298 individuals were hospitalized. Two-thirds were men, two-thirds had been homeless for over a year, most were single, and 79% came from outside New York City. 92% had a previous psychiatric hospitalization. Schizophrenia, generally seen in 2% to 17% of homeless populations,⁴⁴ was diagnosed in 80% of this cohort. Interestingly, 73% of these individuals also had significant medical problems. Two years after the initiation of this program, 55% of these people were either in an institution or living in a community setting.

Racial differences in the utilization of mental health services by 145 African-American and 236 white homeless veterans in nine cities were analyzed by Rosenheck and colleagues. Few differences were noted in service use and treatment outcomes. However, the researchers found noteworthy characteristics of both cohorts, including previous psychiatric hospitalizations for 38% of the African-American and 43% of the white veterans. Alcohol abuse was also common in both groups (44%/53%).⁴⁵

C. Lengths of Stay and Costs of Hospitalization

In Martel's study of homeless persons in Hawaii noted above, the total costs for the admissions for homeless persons were almost $4 million: acute care hospitalizations cost $3.3 million, while the Hawaii State Hospital admissions cost $690,000. These figures are based on average daily costs of $695 and $179, respectively. The authors estimate that the expenditure for "excess" hospitalization of this homeless cohort was $3.5 million. The average length of stay in the psychiatric hospital was considerably shorter for the homeless, 41.7 days compared to 103 days for housed residents. The average length of stay for acute care hospitalization was 10.1 days compared to the statewide average of 7.9 days at that time.³²

Salit and colleagues attempted to untangle the hospital costs associated with homelessness that are not explained by the severity and complexity of illnesses alone.⁴⁶ In this retrospective study, discharge data from New York Health and Hospitals was used to compare 18,864 homeless adults with 383,986 other low-income adults admitted to all general hospitals in New York City during 1992 and 1993. Maternity admissions were excluded from this study.

Mental illness and substance abuse accounted for more than half (51.5%) of the homeless admissions, and less than a quarter (22.8%) of the admissions for low-income housed individuals. Mental health and substance abuse, when included as either a primary or secondary diagnosis, was involved in 80% of the homeless admissions, about twice the rate for the non-homeless admissions. The primary diagnoses of another 20% of the homeless admissions were for potentially preventable conditions: trauma, infectious diseases (excluding HIV/AIDS), respiratory and skin disorders.

After adjustments were made for the differences in mental illness and substance abuse, as well as demographic characteristics and other clinical issues, the authors determined that the lengths of stay for homeless individuals averaged an additional 4.1 days (36%) per admission. These days are thus attributable to homelessness, and the costs of the additional days per discharge averaged $4,094 for psychiatric patients, $3,370 for patients with AIDS, and $2,414 for all patients. The authors conclude that homelessness is associated with distinct and considerable excess cost per hospitalization in New York City, and argue for the funding of housing and supportive services as a means of reducing the high costs of hospitalization in this population.

Starr notes in an accompanying editorial in the New England Journal of Medicine that the costs of failures in other public sectors, such as housing and education, have been shifted into health care.⁴⁷ HMOs and safety net providers that must operate in the health care marketplace are unlikely to be able to absorb these excess costs without public subsidies or risk-adjusted capitation rates.

Homeless persons are associated with excess costs in mental health hospitalizations and accounted for 26% of all Veterans Affairs inpatient costs in 1995.⁴⁸ Shalit and Hartz found that homeless persons accounted for 26% of public hospital expenditures for inpatient mental health and substance abuse treatment, even though this group represented only 10% of discharges.⁴⁹

Other studies mention lengths of stay for hospitalized homeless persons, but do not report on the costs of hospitalizations.

A study from Montreal failed to show a difference in lengths of stay for homeless persons. Raynault and his colleagues from the University of Montreal compared the hospitalizations of 245 homeless persons with 3,553 housed persons admitted to the same hospital from a low-income area. More young men composed the homeless group, mental health diagnoses were more frequent, and cardiovascular and obstetrical diagnoses were rarely seen. The lengths of stay of both groups were similar, although the study design was unable to compare rates of hospitalizations. No cost comparisons were undertaken in this study.⁵⁰

In the London study mentioned above by Lissauer, the mean length of stay for homeless children was shorter than for housed children, 3.6 days compared to 4.5 days. This finding is consistent with the fact that more of the homeless children suffered only mild illness.³¹

Stovall found that homeless veterans admitted for psychiatric hospitalization in Worcester, Massachusetts, had slightly shorter lengths of stay that housed veterans.⁵¹ Homeless veterans with mental disorders had more emergency room visits and more psychiatric hospitalizations during the previous year when compared to housed veterans with chronic mental illness.

IV. Emergency Department Utilization

While several studies below examine the frequency and patterns of emergency department utilization by homeless persons, no study was found that addressed the associated costs.

A. Frequency of Emergency Room Visits

Padgett analyzed a survey of 1260 homeless adults in New York City in 1987 and found that one third of the women and one quarter of the men had visited an emergency department in the previous six months.⁵² Trauma and victimization, with resulting limb fractures, concussions, burns, and skull fractures, occurred 30 times more frequently in this group than in the general population. This study tested a multivariate conceptual model for predicting emergency department use. The high risk profile for men is characterized by higher education, African-American or Hispanic, poorer health, injuries or victimization as risk factors, and less alcohol dependence; men in this group were 58 times more likely to use the emergency department than homeless men in the low risk profile. The high risk women were 146 times more likely to use the emergency department, and were characterized by: currently or previously married, higher levels of alienation, physical disability, poor physical health and injuries, and less alcohol dependence. The rather startling finding was the failure of mental health and substance abuse to predict high use of the emergency department.

This study has interesting implications. Mental illness and substance abuse are common problems faced by homeless persons, yet in this study appear to play only a minor role in utilization of the emergency department. Rather, the treatment of physical health problems and reducing vulnerability to injuries and victimization are paramount. The authors argue that more aggressive enrollment in medical entitlement programs such as Medicaid should be vigorously pursued if we are to reduce utilization of costly emergency department services.

In the San Francisco study performed by Braun and cited above, homeless persons averaged 2.5 visits to the emergency department each year, compared to 1.6 visits for the general SFGHED population.³³ The most frequent reasons for visits to the ED and for admissions to the hospital were: trauma (18%), skin disorders (cellulitis, abscess) 16%, cardio-pulmonary 16%, and psychiatric/substance abuse 13%. Only 7% had a diagnosis of HIV. High rates of self-reported current or past substance abuse were found, including 43% injection drug use, 71% cocaine use, and 64% alcohol use. The authors conclude that the homeless represent a vulnerable population that relies on the emergency room for urgent/emergent and primary health care.

In the two-year Boston study by Taube ³⁴ cited above, 1084 persons followed in the Boston Health Care for the Homeless Program's primary care clinic also visited the public hospital's emergency department an average of 1.6 times each year. This cohort also visited the hospital's urgent care center an average of 1.1 times per year. The total rate of 2.7 emergency or urgent care visits per patient per year is similar to the data reported by Braun above in San Francisco.

To test whether compassionate care for frequent emergency department users would improve patient satisfaction and decrease subsequent utilization, Redelmeier from the University of Toronto in Ontario enrolled 133 consecutive homeless adults presenting to the emergency department who were not acutely psychotic, heavily intoxicated, or medically unstable. This group had high utilization rates, with an average of 7 visits per year, or 0.60 visits per month. More than one third had made two or more visits within two days of each other. The group was randomized to usual care or compassionate care provided by trained volunteers. After one month the intervention lowered ED utilization by one third, from 0.65 visits/month in the usual care group to 0.43 visits/month in the compassionate care group (p = 0.018). The authors conclude that repeat visits to the ED can be avoided in selected homeless individuals through efforts to provide better patient satisfaction.

B. Utilization of Emergency Departments for Primary Care

Several studies have examined the use of emergency departments for primary care by poor and indigent populations. Little and colleagues at Guy's Hospital in London investigated the use of the emergency department by homeless persons as a substitute for primary care. During a six month period, the records were reviewed of all patients who registered in the emergency department with an address of "no fixed abode." 233 visits by 135 homeless patients were made during the study period. 46% of these visits were during normal office hours, and over 80% were for minor problems. About one quarter of the homeless individuals knew the name of the general practitioner with whom they were registered, while the remainder either were not registered with the health district or did not know their registration status. Even though the majority was aware of medical alternatives to the emergency department (e.g., community homeless clinics, general practitioner's office), over half (52.6%) preferred to use the emergency department. The authors suggest that more local services are necessary and community facilities and local general practitioners needed to be more sensitive to the particular needs of homeless persons if costly emergency department utilization is to be reduced.⁵⁴

A study from Liverpool involved a retrospective review of 421,237 emergency department visits during an 8-year period. Homeless persons accounted for only 566 visits, or 0.13% of the ED visits. The authors found no significant differences between the homeless and housed cohorts in demographics or in utilization of psychiatric services. No changes in the rate of emergency room utilization by homeless persons were noted during the 8-year study period.⁵⁵

Homeless families often use the emergency department as a point of entry into the health care system. Orenstein performed a case-control study of 54 homeless families and 108 housed families who presented to the ED during a 9-month period. Each family completed a self-administered questionnaire. The mean age of the children was 3.4 years and the mean maternal age was 27 years. The homeless children had spent an average of 7.8 months in shelters. The sheltered families had more children, more single mothers, less insurance, and higher unemployment than the housed families. The study showed that homeless children were less likely to have had TB testing, had more immunization delays, lacked a regular primary care site, and had higher rates of medical admissions from the ED.⁵⁶

Wood found that homeless families in Los Angeles utilized the emergency department more than housed poor families.⁵⁷ A sample of 194 homeless families from 10 Los Angeles shelters was compared to 196 families selected from the welfare offices of the same area. Medicaid was the primary insurance for both groups (61% for the homeless and 96% from the housed). Homeless families were less likely to identify a provider for primary or preventive care (81% compared to 94%), or for episodic or sick care (72% compared to 95%). Interestingly, over a third of the homeless families who identified a primary provider still used the emergency department for both preventive and episodic sick care compared to 15% and 26%, respectively, of the housed poor families. The findings suggest that homeless families face many barriers in accessing health care.

V. Summary

Poor socioeconomic status is associated with increased morbidity and mortality.^58,59 Homeless persons constitute an eclectic population living in persistent poverty without stable housing with increased severity and complexity of illness as well as decreased access to primary care. We have reviewed the small but growing body of literature that has tested the hypothesis that, in comparison to poor domiciled populations, the utilization patterns of health care services by homeless persons involve more frequent visits to emergency departments as well as more acute care hospital admissions. While each study is limited in design and most are without adequate controls, the preponderance of the literature supports the hypothesis for selected homeless groups.

Studies from large cities in Great Britain have shown that homeless children are hospitalized at rates from 2-9 times that of other poor children. In addition, the social deprivation of homelessness affects the decision of physicians regarding the need for hospital admission, and homeless children are admitted for milder illnesses than children with stable housing and family supports. Homeless children also appear to have a greater severity and frequency of illness and less access to primary care than their housed counterparts. Homeless adults were hospitalized from 2-6 times more frequently than the general population in studies of selected groups in Hawaii, San Francisco, San Jose, Boston, and Worcester, MA.

Several authors have looked at groups of hospitalized patients and found an over-representation of homeless persons: 5.3% of indigent patients in San Diego; 8% of all admissions to two inner city London hospitals; 15% of all persons admitted for suicide attempts in London; 24-28% of medical admissions to Boston's public hospital and 12% of admissions to the ward medical service of a private university teaching hospital in that city; and 46% of all admissions to a New York psychiatric hospital.

In addition to more frequent hospitalizations, homeless persons in selected studies in Hawaii, New York, and Boston have accounted for excess costs per hospitalization when compared to housed cohorts. Such costs are generally attributed to increased lengths of stay: 10.1 days for homeless persons compared to 7.9 days for the statewide population in Hawaii; an additional 4.1 days per admission in New York City were attributable to homelessness when the cohorts were controlled for differences in complexity and co-morbidity of illness, accounting for an average excess cost of $2,414 per admission. In contrast, no differences in lengths of stay between homeless individuals and other low-income patients were noted in Montreal, although the study did not address the comparable costs or rates of hospitalizations. Psychiatric hospitalizations also appear to be more frequent among homeless persons, but lengths of stay are often shorter for homeless than housed persons as noted among veterans in Worcester as well as the homeless in Hawaii. Homeless children also appear to differ from adults, with increased frequency of hospitalizations but decreased lengths of stay, usually because of socioeconomic factors that led to admissions for milder illnesses among homeless children.

Homeless individuals utilize emergency rooms more frequently than housed populations, not only for acute care but also for primary care. Padgett found that one-third of homeless women and one-quarter of homeless men had used an emergency room in the previous six months in New York City. Homeless persons in Toronto who presented to the emergency room had an average of 7 visits per year. Homeless cohorts in San Francisco (enrolled through the emergency department) and Boston (enrolled through a hospital-based primary care clinic for the homeless) used the emergency rooms an average of more than 2.5 times per year. Homeless families and children face additional barriers in accessing primary health care, and have been shown to use the emergency departments as a source of primary care in London, Los Angeles, and Washington, D.C.

VI. Conclusions

Despite methodological difficulties, an emerging body of literature suggests that the patterns of health care utilization by selected homeless sub-groups involve more frequent emergency department visits and acute care hospitalizations, as well as considerable excess costs per hospitalization, when compared to poor but housed populations. Epstein has shown that individuals in the lowest socioeconomic situations have lengths of stays that exceed persons of higher status by 3%-30% and incur hospital charges from 1%-18% higher.⁶⁰ Homeless populations, while diverse and eclectic, are generally accepted to be in the very lowest socioeconomic status and among the poorest of our citizens, and the findings above should hardly be surprising.

The American health care system has turned increasingly to managed care during the past two decades. However, the ability of managed care to improve access and control the costs of health care for vulnerable populations such as the homeless poor is unproven. Enrollment in managed care has grown from 9.5% of the total Medicaid enrollment in 1991 to 40.1% in 1996. While many states initially developed fee-for-service primary care case management programs, several have begun to enroll larger numbers in fully capitated health maintenance organizations (HMOs). To date few states have attempted to enroll the disabled into HMOs, and the fate of vulnerable and high-risk populations such as homeless persons in such systems is still unknown. Medicaid has traditionally provided a broad range of "wrap-around" benefits for special and disabled populations that include case management, transportation, outreach, and public health services. The benefits provided by HMOs are more limited, and may well effect the ability of these plans to provide quality health care to the homeless and other disabled populations.⁶¹

The implications of these studies are profound, particularly as the number of uninsured Americans rises and as more states move to enroll homeless persons in Medicaid managed care programs. The ability of HMOs, hospitals, and safety net programs to provide quality health care for this high-risk "special-needs" population will depend upon appropriate risk adjustment for homeless individuals and families. Payment methods, whether capitation or traditional fee-for-service, must be based upon an understanding of this group's patterns of health care utilization and costs to the system.⁶² In two reports supported jointly by the Division of Programs for Special Populations of the Bureau of Primary Health Care and the National Health Care for the Homeless Council, Wunsch and colleagues at Care for the Homeless in New York City explore several challenges faced by health plans in providing care to homeless persons. The enrollment process is a critical factor, not only because of the difficulty of finding this itinerant population without mailing addresses or phones, but especially because the identification of enrollees with unstable housing within each plan's information management system is absolutely necessary to study costs and utilization patterns and devise effective interventions and service delivery strategies.^63,64

While the studies noted in this paper have begun to examine the utilization of high-cost health care services of emergency rooms and acute care hospitals by homeless persons, little is known of the total medical costs of homeless individuals, including primary and specialty care, pharmacy, laboratory, transportation, intensive case management, outreach services, and chronic and long term care. These costs must be added to the costs of substance abuse and mental health care, which are often difficult to obtain because of mental health carve-outs and disparate federal, state, and local funding sources.

Further research in the patterns of health care utilization among homeless populations will be necessary to evaluate programs and strategies for improving quality of care and health outcomes while reducing costs. Many provocative challenges are presented by the papers cited above, including: the reduction of emergency department visits through accessible and available primary and preventive care that utilizes outreach and intensive case management services; the diversion of hospital admissions and the reduction of lengths of stay and costs through specialized sub-acute and recuperative care facilities; the coordination of primary care with mental health and substance abuse treatment in a population with an extraordinary incidence of dual- and multiple-diagnoses.

Creative health care delivery models, such as those developed by the 128 health care for the homeless programs funded by the Bureau of Primary Health Care of the U. S. Public Health Service, will be required to assure access to coordinated and comprehensive health care to this population.⁶⁵ Such models must bridge the gaps between hospitals and community-based services, between medicine and public health, and among health care, housing and other public sectors (education, welfare, labor, corrections) that are necessary for long term solutions to the vexing and shameful problem of homelessness in the United States.

VII. Endnotes

1. Orwell G. Down and Out in Paris and London. San Diego: Harcourt Brace Jovanovich, Publishers, 1933:213.

2. Burt M, Cohen B. America's Homeless: Numbers, Characteristics, and Programs that Serve Them. Washington D.C.: The Urban Institute Press, 1989.

3. Hoombs ME, Synder M. Homelessness in America: A Forced March to Nowhere. Washington, D.C.: Community for Creative Non-Violence, 1982.

4. Link BG, Susser E, Stueve A, Phelan J, Moore RE, Struening E. "Lifetime and Five-year Prevalence of Homelessness in the United States,"American Journal of Public Health 1994; 84:1907-1912.

5. Medicine Io. Homelessness, Health, and Human Needs. Washington, D.C.: National Academy Press, 1988:242.

6. Brickner PW, Scharer LK, Conanan BA, Savarese M, Scanlon BC. Under the Safety Net: The Health and Social Welfare of the Homeless in the United States. New York: W.W. Norton and Company, 1990:439.

7. O'Connell JJ. "Nontuberculous Respiratory Infections Among the Homeless,"Seminars in Respiratory Infections 1991; 6:247-253.

8. Wlodarczyk D, Prentice R. "Health Issues of Homeless Persons" Western Joiurnal of Medicine 1988; 14:717-719.

9. Breakey WR, Fischer PJ, Kramer M. "Health and Mental Health Problems of Homeless Men and Women in Baltimore," Journal of the American Medical Association 1989; 262:1352-1357.

10. Ferenchick GS. "Medical Problems of Homeless and Non-homeless Persons Attending an Inner City Health Clinic: A Comparative Study," American Journal of Medical Science 1991; 301:379-382.

11. Brudney K, Dobkin J. "Resurgent Tuberculosis in New York City: Human Immunodeficiency Virus, Homelessness, and the Decline of Tuberculosis Control Programs," American Review of Respiratory Diseases 1991; 144:745-749.

12. Allen DM, Lehman JS, Green TA. "HIV Infection Among Homeless Adults and Runaway Youth, United States, 1989-1992," AIDS 1994; 8:1593-1598.

13. Torres RA, Mani S, Altholz J, Brickner PW. "Human Immunodeficiency Virus Infection among Homeless Men in a New York City Shelter," Archives of Internal Medicine 1990; 150:2030-2035.

14. Lebow RM, O'Connell JJ, Oddleifson S, Gallagher KM, Seage GR, Freedberg KA. "AIDS among the Homeless of Boston: A Cohort Study," Journal of Acquired Immune Deficiency Syndromes and Human Retrovirology 1995; 8:292-296.

15. Harnisch JP, Tronca E, Nolan CM, Turck M, Holmes KK. "Diphtheria among Alcoholic Urban Adults: A Decade of Experience in Seattle," Annals of Internal Medicine 1989; 111:71-82.

16. Spach DH, Kanter AS, Dougherty MJ, et al. "Bartonella (Rochalimaea) Quintana Bacteremia in Inner-city Patients with Chronic Alcoholism," New England Journal of Medicine 1995; 332:424-428.

17. Drancourt M, Mainardi JL, Brouqui P, et al. "Bartonella (Rochalimaea) Quintana Endocarditis in Three Homeless Men," New England Journal of Medicine 1995; 332:419-423.

18. Alliegro GM, Barry MA, O'Connell JJ, Crow HM, McCabe WR. "An Outbreak of Invasive Haemophilus Influenzae Type B (Hib) Disease in Homeless Adults," 28th ICAAC Conference, Los Angeles, CA, October, 1989.

19. Stratigos AJ, Stern R, Gonzalez E, Johnson RA, O'Connell JJ, Dover JS. "Prevalence of Skin Disease in a Cohort of Shelter-based Homeless Males," 1998.

20. Robbins JM, Roth LS, Villanueva MC. "Stand Down for the Homeless": Podiatric Screening of a Homeless Popultion in Cleveland," Journal of the Americn Podiatric Medical Association 1996; 86:275-279.

21. Hwang SW, Lebow JM, Bierer MF, O'Connell JJ, Orav EJ, Brennan TA. "Risk Factors for Death in Homeless Adults in Boston," Archives of Internal Medicine 1998; 158:1454-1460.

22. Browne A, Bassuk SS. "Intimate Violence in the Lives of Homeless and Poor Housed Women: Prevalence and Patterns in an Ethnically Diverse Sample," American Journal of Orthopsychiatry 1997; 67:261-278.

23. Wiecha JW, Dwyer JT, Dunn-Strohecker M. "Nutrition and Health Services Needs among the Homeless," Public Health Reports 1991; 106:364-374.

24. "Deaths among the Homeless: Atlanta, Georgia," Morbidity and Mortality Weekly Report 1987; 36:297-299.

25. "Deaths among Homeless Persons: San Francisco, 1985-1990," Morbidity and Mortality Weekly Report 1991; 40:877-880.

26. Hibbs JR, Benner L, Klugman L. "Mortality in a Cohort of Homeless Adults in Philadelphia," New England Journal of Medicine 1994; 331:304-309.

27. Hwang SW, Orav EJ, O'Connell JJ, Lebow JM, Brennan TA. "Causes of Death in Homeless Adults in Boston," Annals of Internal Medicine 1997; 126:625-628.

28. Maclure A, Stewart GT. "Admission of Children to Hospital in Glasgow: Relation to Unemployment and Other Deprivation Variables," Lancet 1984; ii:684-685.

29. Heaton PA, Charton TL. "Burns Affecting Children from Homeless Families," Journal of Maternal and Child Health 1993;18:16-21.

30. Victor CR, Connelly J, Roderick P, Cohen C. "Use of Hospital Services by Homeless Families in an Inner London Health District," British Medical Journal 1989; 299:725-727.

31. Lissauer T, Richman S, Tempia M, Jenkins S, Taylor B. "Influence of Homelessness on Acute Admissions to Hospital," Archives of Disease in Childhood 1993; 69:423-429.

32. Martell JV, Seitz RS, Harada JK, Kobayashi J, Sasaki VK, Wong C. "Hospitalization in an Urban Homeless Population: the Honolulu Urban Homeless Project," Annals of Internal Medicine 1992; 116:299-303.

33. Braun R, Hahn JA, Gottlieb SL, Moss AR, Zolopa AR. "Utilization of Emergency Medical Services by Homeless Adults in San Francisco: Effects of Social Demographic Factors," AHSR & FHRS Annual Meeting Abstract Book; 12:114.

34. Taube RL. "Health Care Service Utilization Patterns of Homeless Adults in an Urban Public Hospital." To be submitted for publication 1998.

35. Weinreb L, Goldberg R, Perloff J. "Health Characteristics and Medical Service Use Patterns of Sheltered Homeless and Low-income Housed Mothers," Journal of General Internal Medicine 1998; 13:389-397.

36. Rosenheck RA, Leda C, Sieffert D, Burnette C. "Fiscal Year 1995 End of Year Survey of Homeless Veterans in VA Inpatient and Domiciliary Care Programs," West Haven, CT: Northeast Program Evaluation Center, 1996.

37. Winkleby MA, Rockhill B, Jatulis D, Fortmann SP. "The Medical Origins of Homelessness," American Journal of Public Health 1992; 82:1395-1398.

38. O'Connell JJ, Chin B, Taube R. "Statewide Hospitalization Rates for Boston's Adult Homeless Individuals." Submitted for publication 1998.

39. Bindman AB, Grumbach K, Keane D, Lurie N. "Collecting Data to Evaluate the Effect of Health Policies on Vulnerable Populations," Family Medicine 1993; 25:114-119.

40. Black ME, Scheuer MA, Victor C, Benzeval M, Gill M, Judge K. "Utilization by Homeless People of Acute Hospital Services in London," British Medical Journal 1991; 303:958-961.

41. Cullum S, O'Brien S, Burgess A, Booth J, Lant A, Ctalan J. "Deliberate Self Harm: The Hidden Population," Health Trends 1995-96; 27:130-132.

42. Herman M, Galanter M, Lifshutz H. "Combined Substance Abuse and Psychiatric Disorders in Homeless and Domiciled Patients," American Journal of Drug and Alcohol Abuse 1991; 17:415-422.

43. Marcos LR, Cohen NL, Nardacci D, Brittain J. "Psychiatry Takes to the Streets: The New York City Initiative for the Homeless Mentally Ill," American Journal of Psychiatry 1990; 147:1557-1561.

44. Smith EM, North CS, Spitznagel EL. "A Systematic Study of Mental Illness and Treatment in 600 Homeless Men," Annals of Clinical Psychiatry 1992; 4:111-120.

45. Rosenheck R, Leda C, Frisman L, Gallup P. "Homeless Mentally Ill Veterans: Race, Service Use, and Treatment Outcomes," American Journal of Orthopsychiatry 1997; 67:632-638.

46. Salit SA, Kuhn EM, Harz AJ, Vu JM, Mosso AL. "Hospitalization Costs Associated with Homelessness in New York City," New England Journal of Medicine 1998; 338:1734-1740.

47. Starr P. "The Homeless and the Public Household (editorial)," New England Journal of Medicine 1998; 338:1761-1763.

48. Rosenheck R, Kizer KW. "Hospitalizations and the Homeless," New England Journal of Medicine 1998; 339:1166.

49. Salit SA, Hartz AJ. "Hospitalizations and the Homeless": Letter to the Editor, New England Journal of Medicine 1998; 339:1167.

50. Raynault MF, Battista RN, Joseph L, Fournier L. "Reasons for Hospitalization and Length of Stay of a Homeless Population in Montreal," Canadian Journal of Public Health 1994; 85:274-277.

51. Stovall J, Flaherty JA, Bowden B, Schoeny M. "Use of Psychiatric Services by Homeless Veterans," Journal of Mental Health Administration 1997; 24:98-102.

52. Padgett DK, Struening EL, Andrews H, Pittman J. "Predictors of Emergency Room Use by Homeless Adults in New York City: The Influence of Predisposing, Enabling, and Need Factors," Social Science Medicine 1995; 41:547-556.

53. Redelmeier DA, Molin JP, Tibshirani RJ. "A Randomized Trial of Compassionate Care for the Homeless in an Emergency Department," Lancet 1995; 345:1131-1134.

54. Little GF, Watson DP. "The Homeless in an Emergency Department: A Patient Profile," Journal of Accident and Emergency Medicine 1996; 13:415-417.

55. Earnshaw SM, Barnes RC, Brown R. "Trends in the Use of Accident and Emergency Services by the Homeless on the Wirral," Journal of Accident and Emergency Medicine 1996; 13:334-336.

56. Orenstein JB, Boenning DA, Engh EP, Zimmerman SJ. "Emergency Care of Children in Shelters," Pediatric Emergency Care 1992; 8:313-317.

57. Wood D, Valdez RB. "Barriers to Medical Care for Homeless Families Compared with Housed Poor Families," American Journal of Diseases of Children 1991; 145:1109-1115.

58. Lantz PM, House JS, Lepkowski JM, Williams DR, Mero RP, Chen J. "Socioeconomic Factors, Health Behaviors, and Mortality: Results from a Nationally Representative Prospective Study of US Adults," Journal of the American Medical Association 1998; 279:1703-1708.

59. Andrulis DP. "The Urban Health Penalty: New Dimensions and New Directions in Inner City Health Care." Public Policy Papers. Vol. 1. Philadelphia, PA: American College of Physicians, 1997:48.

60. Epstein AM, Stern RS, Weissman JS. "Do the Poor Cost More? A Multihospital Study of Patients' Socioeconomic Status and Use of Hospital Resources," New England Journal of Medicine 1990; 322:1122-1128.

61. Holahan J, Zuckerman S, Evans A, Rangarajan S. "Medicaid Managed Care in Thirteen States," Health Affairs 1998; 17:43-63.

62. Fowles JB, Weiner JP, Knutson D, Fowler E, Tucker AM, Ireland M. "Taking Health Status into Account When Setting Capitation Rates: A Comparison of Risk-adustment Methods," Journal of the American Medical Association 1996; 276:1316-1321.

63. Wunsch D. Searching for the Right Fit: Homelessness and Medicaid Managed Care. New York City: Care for the Homeless, 1998:27.

64. Wunsch D. Can Managed Care Work for Homeless People? Guidance for State Medicaid Programs. New York City: Care for the Homeless, 1998:36.

65. McMurray-Avila M. Organizing Health Services for Homeless People: A Practical Guide. Nashville: National Health Care for the Homeless Council, 1998.

This project was funded by the Health Care for the Homeless Branch, Division of Programs for Special Populations, of the Bureau of Primary Health Care, with the generous support of the
National Health Care for the Homeless Council.