Abstract
OBJECTIVE: Although cognitive behavior therapy (CBT) is efficacious for major depression in patients with heart failure (HF), approximately half of patients do not remit after CBT. To identify treatment moderators that may help guide treatment allocation strategies and serve as new treatment targets, we performed a secondary analysis of a randomized clinical trial. Based on evidence of their prognostic relevance, we evaluated whether clinical and activity characteristics moderate the effects of CBT. METHODS: Participants were randomized to enhanced usual care (UC) alone or CBT plus enhanced UC. The single-blinded outcomes were 6-month changes in Beck Depression Inventory total scores and remission (defined as a Beck Depression Inventory ≤ 9). Actigraphy was used to assess daily physical activity patterns. We performed analyses to identify the specific activity and clinical moderators of the effects of CBT in 94 adults (mean age = 58, 49% female) with HF and major depressive disorder. RESULTS: Patients benefited more from CBT (versus UC) if they had the following: more medically severe HF (i.e., a higher New York Heart Association class or a lower left ventricular ejection fraction), more stable activity patterns, wider active periods, and later evening settling times. These individual moderator effects were small (|r| = 0.10-0.21), but combining the moderators yielded a medium moderator effect size (r = 0.38; 95% CI = 0.20-0.52). CONCLUSIONS: These findings suggest that increasing the cross-daily stability of activity patterns, and prolonging the daily active period, might help increase the efficacy of CBT. Given moderating effects of HF severity measures, research is also needed to clarify and address factors in patients with less severe HF that diminish the efficacy of CBT. CLINICAL TRIAL REGISTRATION: clinicaltrials.gov identifier: NCT01028625.