Employee costs before and after treatment initiation for bipolar disorder.

OBJECTIVE

To examine pretreatment and posttreatment total medical costs and overall mental healthcare costs for patients with bipolar disorder (BPD) treated with different medication regimens (alone and in combination) vs an untreated (UnTx) cohort.

STUDY DESIGN

Retrospective employer-based administrative database analysis of costs before and after the start of therapy for BPD from 2001 through 2004.

METHODS

Patients were grouped into 3 cohorts based on type of therapy vs the UnTx cohort. Total medical and mental health-specific healthcare costs were compared between the 6-month preindex period and the 6-month postindex period. A mean index date of the treated cohorts was assigned to the UnTx cohort. Regression models were used to calculate cost differences.

RESULTS

Reductions in direct medical costs among 1284 patients were largest for the cohort receiving atypical antipsychotics (ATYP) only (-$2886 [n = 55]), followed by the UnTx cohort (-$365 [n = 306]) and the cohort receiving ATYP plus other BPD medications (BOTH) (-$78 [n = 369]). In the cohort receiving other BPD medications (OTHR), costs increased by $168 (n = 554). Differences between the ATYP cohort and the OTHR cohort were significant (P = .04). For specific direct mental health-related costs, the cost changes were -$1523 for the ATYP cohort, -$441 for the OTHR cohort, -$38 for the BOTH cohort, and -$704 for the UnTx cohort. Differences between the ATYP cohort and the OTHR and BOTH cohorts were significant (P = .02 and P = .002, respectively).

CONCLUSIONS

Patients using ATYP for BPD seem to have the largest cost reductions. Additional investigation is needed to identify whether the UnTx cohort had the least severe BPD, had nonadherent prescription fill behavior, or both.