Impact of a medical home model on costs and utilization among comorbid HIV-positive Medicaid patients.

OBJECTIVES: The Pennsylvania Chronic Care Initiative (CCI) was a statewide patient-centered medical home (PCMH) initiative implemented from 2008 to 2011. This study examined whether the CCI affected utilization and costs for HIV-positive Medicaid patients with both medical and behavioral health comorbidities. STUDY DESIGN: Nonrandomized comparison of 302 HIV-positive Medicaid patients treated in 137 CCI practices and 2577 HIV-positive Medicaid patients treated elsewhere. METHODS: All patients had chronic medical conditions (diabetes, chronic obstructive pulmonary disease, asthma, or congestive heart failure) and a psychiatric and/or substance use disorder. Analyses used Medicaid claims data to examine changes in total per patient costs per month from 1 year prior to 1 year following an index episode. Propensity score weighting was used to adjust for potential sample differences. Secondary outcomes included costs and utilization of emergency department, inpatient, and outpatient/pharmacy services. RESULTS: We identified an average total cost savings of $214.10 per patient per month (P = .002) for the CCI group relative to the non-CCI group. This was a function of decreased inpatient medical (-$415.69; P = .007) and outpatient substance abuse treatment (-$4.86; P = .001) costs, but increased non-HIV pharmacy costs ($158.43; P = .001). Utilization for the CCI group, relative to the non-CCI group, was correspondingly decreased for inpatient medical services (odds ratio [OR], 0.619; P = .002) and inpatient services overall (OR, 0.404; P = .001), but that group had greater numbers of outpatient medical service claims when they occurred (11.7%; P = .003) and increased non-HIV pharmacy claims (9.7%; P = .001). CONCLUSIONS: There was increased outpatient service utilization, yet relative cost savings, for HIV-positive Medicaid patients with medical and behavioral health comorbidities who were treated in PCMHs.