Medicaid prescription cost containment and schizophrenia: a retrospective examination.

Objectives: In 2002, the Mississippi Division of Medicaid enacted several policies to curb prescription spending including increasing prescription copayments from $1 to $3 per brand, a cap of 7 prescriptions per month, a 34-day supply limitation, and a 5% reduction in dispensing fees. The objectives of this study were to examine the influence of these policies on (1) compliance to antipsychotic medications and (2) mental health care utilization and payments among patients with schizophrenia.

Methods: This study used a 12-month pretest and 12-month posttest longitudinal design to compare the effect of these policies among patients with schizophrenia in Minnesota and Indiana, who had less restrictive cost-containment using administrative claims data. Generalized estimating equations were used to run difference in difference models to compare medication compliance (proportion of days covered) and health care utilization in Mississippi to the control states.

Results: After policy adoption, patients in Mississippi were 4.87% less compliant with antipsychotic treatments and experienced 20.5% more 90 day antipsychotic treatment gaps than patients in the control states. Although these policies did not affect inpatient or emergency department care among patients with schizophrenia, there was a 3.7% reduction in outpatient mental health visits and a 4.2% reduction in mental health care payments.

Conclusions: Despite the potential for savings, policy makers should consider carefully the potential adverse consequences that may arise from implementing aggressive cost-containment policies among patient with severe mental illness.