Insurance parity and the use of outpatient mental health care following a psychiatric hospitalization.

CONTEXT: Mental health services are typically subject to higher cost sharing than other health services. In 2008, the US Congress enacted legislation requiring parity in insurance coverage for mental health services in group health plans and Medicare Part B.

OBJECTIVE: To determine the relationship between mental health insurance parity and the use of timely follow-up care after a psychiatric hospitalization.

DESIGN, SETTING, AND POPULATION: We reviewed cost-sharing requirements for outpatient mental health and general medical services for 302 Medicare health plans from 2001 to 2006. Among 43 892 enrollees in 173 health plans who were hospitalized for a mental illness, we determined the relation between parity in cost sharing and receipt of timely outpatient mental health care after discharge using cross-sectional analyses of all Medicare plans and longitudinal analyses of 10 plans that discontinued parity compared with 10 matched control plans that maintained parity.

MAIN OUTCOME MEASURES: Outpatient mental health visits within 7 and 30 days following a discharge for a psychiatric hospitalization.

RESULTS: More than three-quarters of Medicare plans, representing 79% of Medicare enrollees, required greater cost sharing for mental health care compared with primary or specialty care. The adjusted rate of follow-up within 30 days after a psychiatric hospitalization was 10.9 percentage points greater (95% confidence interval [CI], 4.6-17.3; P < .001) in plans with equivalent cost sharing for mental health and primary care compared with plans with mental health cost sharing greater than primary and specialty care cost sharing. The association of parity with follow-up care was increased for enrollees from areas of low income and less education. Rates of follow-up visits within 30 days decreased by 7.7 percentage points (95% CI, -12.9 to -2.4; P = .004) in plans that discontinued parity and increased by 7.5 percentage points (95% CI, 2.0-12.9; P = .008) among control plans that maintained parity (adjusted difference in difference, 14.2 percentage points; 95% CI, 4.5-23.9; P = .007).

CONCLUSION: Medicare enrollees in health plans with insurance parity for mental health and primary care have markedly higher use of clinically appropriate mental health services following a psychiatric hospitalization.