Clinical features associated with poor pharmacologic adherence in bipolar disorder: results from the STEP-BD study

Poor medication adherence is common among bipolar patients.

We examined prospective data from 2 cohorts of individuals from the Systematic Treatment Enhancement Program for Bipolar Disorder (STEP-BD) study (1999-2005) with bipolar disorder. Clinical and sociodemographic features associated with missing at least 25% of doses of at least 1 medication were assessed using logistic regression, and a risk stratification model was developed and validated.

Of 3,640 subjects with 48,287 follow-up visits, 871 (24%) reported nonadherence on 20% or more study visits. Clinical features significantly associated (P < .05) with poor adherence included rapid cycling, suicide attempts, earlier onset of illness, and current anxiety or alcohol use disorder. Nonadherence during the first 3 months of follow-up was associated with less improvement in functioning at 12-month follow-up (P < .03). A risk stratification model using clinical predictors accurately classified 80.6% of visits in an independent validation cohort.

Risk for poor medication adherence can be estimated and may be useful in targeting interventions.