Use of medical homes by patients with comorbid physical and severe mental illness

Background: Patients with comorbid severe mental illness (SMI) may use primary care medical homes differently than other patients with multiple chronic conditions (MCC). Objective: To compare medical home use among patients with comorbid SMI to use among those with only chronic physical comorbidities. Research Design: We examined data on children and adults with MCC for fiscal years 2008-2010, using generalized estimating equations to assess associations between SMI (major depressive disorder or psychosis) and medical home use. Subjects: Medicaid and medical home enrolled children (age, 6-17 y) and adults (age, 18-64 y) in North Carolina with ≥2 of the following chronic health conditions: major depressive disorder, psychosis, hypertension, diabetes, hyperlipidemia, seizure disorder, asthma, and chronic obstructive pulmonary disease. Measures: We examined annual medical home participation (Z1 visit to the medical home) among enrollees and utilization (number of medical home visits) among participants. Results: Compared with patients without depression or psychosis, children and adults with psychosis had lower rates of medical home participation (-12.2 and -8.2 percentage points, respectively, P < 0.01) and lower utilization (-0.92 and -1.02 visits, respectively, P < 0.01). Children with depression had lower participation than children without depression or psychosis (-5.0 percentage points, P < 0.05). Participation and utilization among adults with depression was comparable with use among adults without depression or psychosis (P > 0.05). Conclusions: Overall, medical home use was relatively high for Medicaid enrollees with MCC, though it was somewhat lower among those with SMI. Targeted strategies may be required to increase medical home participation and utilization among SMI patients.