Healthcare costs associated with treatment of bipolar disorder using a mood stabilizer plus adjunctive aripiprazole, quetiapine, risperidone, olanzapine or ziprasidone.

OBJECTIVE: Bipolar disorder has an associated economic burden due to its treatment, including medication and hospitalization costs as well as costs associated with treatment of comorbid conditions. This study compared healthcare costs in patients treated with a mood stabilizer and adjunctive aripiprazole versus adjunctive olanzapine, quetiapine, risperidone or ziprasidone.

RESEARCH DESIGN AND METHODS: A retrospective propensity score-matched cohort study was conducted in the LabRx integrated claims database from January 2003 to December 2006. Patients (18-65 years) with bipolar disorder and 180 days of pre-index enrolment without atypical treatment and 90 days post-index enrolment were eligible. Mood stabilizer therapy was initiated prior to index atypical prescription. Generalized gamma regressions were used to compare the total healthcare costs of adjunctive aripiprazole treatment and treatment with adjunctive olanzapine, quetiapine, risperidone or ziprasidone.

RESULTS: After controlling for differences in baseline characteristics and pre-index cost, psychiatric costs and subtotal psychiatric and general medical costs were higher for all adjunctive atypicals than adjunctive aripiprazole (p<0.001). Based on gamma regressions cost ratios, there was no significant difference in general medical costs between aripiprazole and ziprasidone, olanzapine, or quetiapine; risperidone general medical costs were 18% higher versus aripiprazole (p=0.041). Aripiprazole pharmacy costs were higher than quetiapine and risperidone (p<0.001) but not olanzapine or ziprasidone. Total healthcare costs were higher for ziprasidone, olanzapine, or risperidone (p<0.001) but not quetiapine.

LIMITATIONS: Methodological restriction of patients to those newly initiated on an atypical antipsychotic and incomplete medication history limit the generalizability of the findings.

CONCLUSION: Adjunctive aripiprazole may have economic benefits over other atypicals in terms of lower psychiatric treatment costs than adjunctive olanzapine, quetiapine, risperidone or ziprasidone, and lower total healthcare costs than adjunctive olanzapine, risperidone or ziprasidone.