OBJECTIVES

: To examine predictors of presumptive antipsychotic polypharmacy (APP), health care resource utilization (HCRU) and costs among US insured patients initiating antipsychotic medication, stratified by age.

METHODS

: Commercial and Medicare Advantage with Part D enrollees with antipsychotic medication claims for ≥5 weeks between 01JAN2016 - 31DEC2016 were identified from an administrative claims database. The first antipsychotic claim was the index date. Continuous health plan enrollment was required 6 months before index (baseline) and 12 months after (follow-up). An APP episode was defined as ≥37 days of overlapping supply of >1 antipsychotic. Behavioral health-(BH) related HCRU and costs were measured in baseline and follow-up. Logistic regression examined predictors of APP within age groups: children (<18 years), adults (18-64), and seniors (65+).

RESULTS

: 29,951 patients were included; 1,303 (4%) experienced ≥1 episode of APP during follow-up. Adult and senior patients with a baseline BH-related hospitalization (adult odds ratio [OR] 1.5; p<0.001; senior OR 1.4; p=0.010) or schizophrenia diagnosis (adult OR 2.5; p<0.001; senior OR 1.9; p=0.001) had higher odds of APP. A baseline anxiolytic claim increased odds of APP among children (OR 1.9, p=0.032). Adults with APP were higher baseline utilizers of nearly all BH-related outpatient and inpatient services while children’s baseline BH-related HCRU did not differ by APP. Seniors with APP were higher utilizers of acute BH-related services during baseline versus seniors without APP. Follow-up HCRU was significantly higher among patients with APP within each age group. Total mean BH-related follow-up costs were double among adults ($20,989 vs $9,631; p<0.001) and seniors with APP ($13,368 vs $6,558; p<0.001), and nearly triple among children with APP ($28,990 vs $10,799; p<0.001).

CONCLUSIONS

: Predictors of APP differed by age. HCRU and costs were higher among patients with APP. More research is needed to enhance understanding of APP and the impact on HCRU and costs.