Use patterns for antipsychotic medications in Medicaid patients with schizophrenia

Objective: We investigated the use patterns for antipsychotic medications g enerated by Medicaid patients with schizophrenia. Method: Paid claims data from the California Medicaid program (MediCal) were used to identify 2655 p atients with schizophrenia. Data from 1987-1996 were used, during which tim e Medi-Cal maintained prior authorization restrictions on second generation antipsychotic drugs. Prescription records were used to identify 3 patterns of antipsychotic drug use: no drug therapy for over 1 year; delayed onset of antipsychotic drug therapy; and switches in antipsychotic drugs within 1 year. Multiple logistic regression models were used to identify factors af fecting these antipsychotic drug use patterns. Results: Conventional antips ychotic medications account for over 98% of all patient treatment episodes. Over 24% of patients with schizophrenia do not use any antipsychotic medic ation for periods lasting up to 1 year. Over 24% of treated patients delaye d the use of antipsychotic medications at least 30 days. For those patients who did not delay their use of antipsychotic medications, over 47% switche d or augmented their initial antipsychotic medication during the first trea tment year. Only 11.6% of treated patients achieved 1 year of uninterrupted antipsychotic drug therapy. The mean duration of uninterrupted therapy was 142 days. Discussion: Antipsychotic drug use patterns suggest that convent ional antipsychotic medications do not meet the therapeutic needs of patien ts with schizophrenia.