Depressive symptoms moderate the relationship between medication regimen complexity and objectively measured medication adherence in adults with heart failure.

Patients with heart failure (HF) take many medications to manage their HF and comorbidities, and 20-50% experience depression. Depressed individuals with more complex medication regimens may be at greater risk for poor adherence. The aim of this study was to assess depressive symptoms as a moderator of the relationship between medication regimen complexity and medication adherence in an observational study of patients with HF. In hierarchical linear regression with the final sample of 299, the interaction of medication regimen complexity and depressive symptoms predicted medication adherence, p < .05. For individuals with higher levels of depressive symptoms [1 standard deviation (SD) above the mean], more regimen complexity was associated with lower adherence. For individuals with low (1 SD below the mean) or average levels of depressive symptoms, regimen complexity was unrelated to medication adherence. Care management strategies, including pillboxes and caregiver involvement, may be valuable in HF patients with depression.