摘要：Objectives. We studied 6494 Boston Health Care for the Homeless Program (BHCHP) patients to understand the disease burden and health care utilization patterns for a group of insured homeless individuals. Methods. We studied merged BHCHP data and MassHealth eligibility, claims, and encounter data from 2010. MassHealth claims and encounter data provided a comprehensive history of health care utilization and expenditures, as well as associated diagnoses, in both general medical and behavioral health services sectors and across a broad range of health care settings. Results. The burden of disease was high, with the majority of patients experiencing mental illness, substance use disorders, and a number of medical diseases. Hospitalization and emergency room use were frequent and total expenditures were 3.8 times the rate of an average Medicaid recipient. Conclusions. The Affordable Care Act provides a framework for reforming the health care system to improve the coordination of care and outcomes for vulnerable populations. However, improved health care coverage alone may not be enough. Health care must be integrated with other resources to address the complex challenges presented by inadequate housing, hunger, and unsafe environments. Several million Americans experience being homeless every year, and the majority of them cannot afford health insurance. 1 These individuals live on the periphery of society, struggling in abject poverty. They must prioritize basic shelter, safety, and food, and therefore often forgo medical care until conditions become urgent or irreversible. Unmanaged and worsening medical conditions can further extend the duration of homelessness and associated economic problems (e.g., unemployment). Additionally, many homeless individuals are held in the grip of addiction and have mental illness. 2 Given this complex set of circumstances, often compounded by a lack of health insurance coverage, providing medical care for these individuals can be challenging. Care often remains fragmented, taking place in emergency departments (EDs) and multiple inpatient and outpatient settings. The Medicaid expansion through the Affordable Care Act (ACA) will be an unprecedented opportunity to improve access to health services for poor and homeless individuals around the country. Starting in 2014, individuals with incomes up to 138% of the federal poverty level will be eligible for Medicaid in states that choose to expand their Medicaid program. Given the high uninsured rate and low incomes among homeless people, they stand to benefit immensely from this expansion. Although expanded coverage will almost certainly increase access to health care for many, little information is available on what types of services homeless patients will use when insurance is available. Homeless individuals have high rates of mental illness (e.g., depression) and certain medical illnesses (e.g., HCV or diabetes mellitus). 3–5 Previous investigations have shown a high level of health care utilization. 6–8 For example, in a survey of 2578 homeless patients, Kushel et al. 9 found that 40% of respondents had 1 or more ED visit in the last year, and 7.9% had 3 or more visits in the last year. These previous studies mainly used survey data, relied on self-reported data, or examined medical records of a single clinic, and many of the study populations were uninsured. Although these studies provide important information on the homeless population, the disease profiles obtained this way are not always complete, and there is incomplete information on health care utilization. Furthermore, they do not show utilization patterns for an insured homeless population. With health insurance, homeless individuals may have greater access to medications and preventive care that could reduce use of EDs and inpatient care. In the context of high rates of addiction, mental illness, and cognitive impairment, these crisis-driven utilization patterns may also persist in insured patients while expanding access to a wider range of services. In Massachusetts, early Medicaid expansions since the 1990s have allowed a high percentage of homeless individuals to be insured under Medicaid, perhaps higher than most states in the country. Although Massachusetts is perhaps best known for its 2006 Medicaid expansion, unaccompanied homeless men and women were most beneficially affected by its 1115 waiver expansion in 1996. This expansion opened MassHealth (Massachusetts Medicaid) to chronically unemployed residents, and doubled the percentage of unaccompanied adults with Medicaid benefits from 30% to 60%. This expanded access to a variety of services for homeless men and women. The 2006 expansion built on this base and increased the percentage of insured homeless men and women; internal Boston Health Care for the Homeless Program (BHCHP) data demonstrated nearly 80% of patients have Medicaid or Medicare coverage. Therefore, Massachusetts served as a unique environment in which to identify patterns of medical care utilization in the Medicaid enrolled homeless population. We examined Massachusetts Medicaid claims data in 2010 for a large cohort of homeless individuals seen at BHCHP. The program provides care to approximately 40% of the homeless population in Massachusetts. 10 Augmenting previous studies, this study provided a unique perspective by analyzing claims data for a large sample of homeless people with health insurance coverage. In addition to providing a comprehensive understanding of the disease burden among homeless individuals, this data set included both behavioral health services for mental illness and substance use disorders (SUDs) and general medical care. This provided an opportunity to understand current service use across these sectors in preparation for the integrated care envisioned in future care models.
