Through the Looking Glass: Estimating Effects of Medical Homes for People with Severe Mental Illness
利用多种统计方法分析北卡罗来纳州医疗补助数据，发现医疗之家对严重精神疾病患者（精神分裂症、双相障碍、重度抑郁）总体上增加了初级和专科护理使用、药物依从性和支出，但未节省保险费用。
OBJECTIVE: To examine whether medical homes have heterogeneous effects in different subpopulations, leveraging the interpretations from a variety of statistical techniques. DATA SOURCES/STUDY SETTING: Secondary claims data from the NC Medicaid program for 2004-2007. The sample included all adults with diagnoses of schizophrenia, bipolar disorder, or major depression who were not dually enrolled in Medicare or in a nursing facility. STUDY DESIGN: We modeled a number of monthly service use, adherence, and expenditure outcomes using fixed effects, generalized estimating equation with and without inverse probability of treatment weights, and instrumental variables analyses. DATA COLLECTION: Data were received from the Carolina Cost and Quality Initiative. PRINCIPAL FINDINGS: The four estimation techniques consistently revealed generally positive associations between medical homes and access to primary care, specialty mental health care, greater medication adherence, slightly lower emergency room use, and greater expenditures. These findings were consistent across all three major severe mental illness diagnostic groups. Some heterogeneity in effects were noted, especially in preventive screening. CONCLUSIONS: Expanding access to primary care-based medical homes for people with severe mental illness may not save money for insurance providers, due to greater access for important outpatient services with little cost offset. Health services research examining more of the treatment heterogeneity may contribute to more realistic projections about medical homes outcomes.