Longitudinal racial/ethnic disparities in antimanic medication use in bipolar-I disorder.

OBJECTIVE

To examine racial/ethnic longitudinal disparities in antimanic medication use among adults with bipolar-I disorder.

METHODS

Observational study using administrative data from Florida's Medicaid program, July 1997 to June 2005, for enrollees diagnosed with bipolar-I disorder (N = 13,497 persons; 126,413 person-quarters). We examined the likelihood of receiving one of the following during a given quarter: (1) any antimanic agent (antipsychotic or mood stabilizer) or none, and (2) mood stabilizers, antipsychotic monotherapy, or neither. Binary and multinomial logistic regression models predicted the association between race/ethnicity and prescription fills, adjusting for clinical and demographic characteristics. Cohort indicators for year that the enrollee met study criteria were included to account for cohort effects.

RESULTS

Averaging over all cohorts and quarters, compared with whites, blacks had lower odds of filling any antimanic and mood stabilizer prescriptions specifically (40%-49% and 47%-63%, respectively), but similar odds of filling prescriptions for antipsychotic monotherapy. After Bonferroni adjustment, compared with whites, there were no statistically significant disparities for Hispanics in filling prescriptions for any, or specific antimanic medications.

CONCLUSIONS

Rates of antimanic medication use were low regardless of race/ethnicity. However, we found disparities in antimanic medication use for blacks compared with whites and these disparities persisted over time. We found no Hispanic-white disparities. Quality improvement efforts should focus on all individuals with bipolar disorder, but particular attention should be paid to understanding disparities in medication use for blacks.