Analysis of healthcare utilization patterns and adherence in patients receiving typical and atypical antipsychotic medications

SUMMARY Objective: To examine the effects of typical and atypical antipsychotics on medication adherence and healthcare resource utilization. Research design and methods: This was a retrospective observational cohort analysis of pharmacy and medical health insurance reimbursement data of patients from a southeastern United States health plan. Pharmacy data of subjects between 6 and 65 years of age were identified. Inclusion criteria included initiation of a single antipsychotic agent between July 1, 1999 and September 30, 2000; no antipsychotic medication usage 6 months prior to the index prescription date; and continuous health plan enrollment for the 18-month study period. Multivariable methods were utilized to analyze healthcare resource utilizations between groups. Outcome measures: Primary outcome measures included: (1) adherence and persistence with antipsychotic therapy; (2) healthcare utilization for outpatient office and hospital visits, inpatient hospital visits, and emergency room visits; and (3) therapy modifications and concomitant medications. Results: A total of 469 patients met initial study criteria. Atypical and typical antipsychotics were prescribed to 384 and 85 patients, respectively. Length of therapy (days) for the atypical cohort was significantly longer (136 vs 80; p