The use of public mental health services by older Californians and complementary service system effects.

Older adults with mental disorders are less likely to use specialty care than any other population group. In this study, we created a multisource secondary data file and examined the use of public mental health services by older adults across California's county-based community mental health systems. We specifically considered complementary service system effects relative to compositional effects representing individual service users and more general contextual effects. Service use was defined in terms of treated prevalence rates, repeat service use, and intensity of service use. Differences across 49 county-based systems were evaluated by regressing the 3 service use measures onto compositional characteristics including client age, diagnosis, and insurance status; variables reflecting complementary service systems including mental health, health, long-term care, and aging services; and other contextual effects such as the size of the county population and average education level. The analyses were adjusted statistically for regional, yearly, and seasonal differences, and for longitudinal clustering within the 49 counties over 12 quarters of observation. Results suggested that older adults' service use varied significantly from one county to the next, and differences were associated with both compositional and contextual effects. As the aging population continues to grow and place an increasing demand on public mental health service systems, this research may help policy makers and program administrators understand some of the critical elements that affect service use patterns among older adults.