A Propensity Score Analysis of Homework Adherence-Outcome Relations in Cognitive Behavioral Therapy for Depression

Abstract

Little is known about whether or not a consistently high level of homework adherence over the course of therapy benefits patients. This question was examined in two samples of patients who were receiving individual Cognitive Behavioral Therapy (CBT) for depression (Ns = 128 [Sequenced Treatment Alternatives to Relieve Depression: STAR-D] and 183 [Continuation Phase Cognitive Therapy Relapse Prevention: C-CT-RP]). Logistic and linear regression and propensity score models were used to identify whether or not clinician assessments of homework adherence differentiated symptom reduction and remission, as assessed by the Hamilton Depression Rating Scale-17 (HDRS-17), the Quick Inventory of Depressive Symptomatology-Self-Reported Scale (QIDS-SR), and the QIDS-Clinician Scale (QIDS-C). CBT-related response and remission were equally likely between both high and low homework adherers in both studies and in all models. But in propensity adjusted models that adjusted for session attendance, for both the STAR-D and C-CT-RP samples, greater homework adherence was significantly associated with greater response and remission from depression in the first and last 8 sessions of CBT. Our results suggest that homework adherence can account for response and remission early and late in treatment, with adequate session attendence.

Trial registration: ClinicalTrials.gov NCT00021528 NCT00118404 NCT00183664 NCT00218764.

Keywords: cognitive behavioral therapy; depression; homework adherence; outcome; propensity score analysis.

Copyright © 2018. Published by Elsevier Ltd.

Figures

Figure 1.

Histograms of propensity scores for the Sequenced Treatment Alternative to Relieve Depression (STAR-D) study and the Continuation Phase Cognitive Therapy Relapse Prevention (C-CT-RP) trial.