Quantity and Quality of Homework Compliance: A Meta-Analysis of Relations With Outcome in Cognitive Behavior Therapy

- We present a meta-analysis of homework adherence, quantity and quality
- Quantity and quality produced similar effect sizes in adherence-outcome relations
- Heterogeneity and overlapping confidence intervals underscore the need for further research to clarify these effects

Homework assignments have been shown to produce both causal and correlational effects in prior meta-analytic reviews of cognitive behavior therapy (CBT), but this research area has been characterized by a focus on the amount of compliance (i.e., quantity), and little is known about the role of skill acquisition (i.e., quality). A landmark study by Neimeyer and Feixas (1990) showed stronger homework-outcome relations when quality was assessed, but previous reviews have not considered whether the same pattern is evident across studies. Seventeen studies of CBT (N = 2,312 clients) published following calls for research on homework quality were included in the current meta-analysis. In the present review, homework compliance relations were demonstrated when outcome was assessed at posttreatment (quality Hedges' g = 0.78, 95% Confidence Interval [CI] = 0.03 to 1.53, k = 3, n = 417; quantity g = 0.79, 95% CI = 0.57 to 1.02, k = 15, n = 1537) and at follow-up (quality g = 1.07, 95% CI = 0.06 to 2.08, k = 3, n = 417; quantity g = 0.51, 95% CI = 0.28 to 0.74, k = 7, n = 1291). All effect sizes were different from 0, ps < .05. Differences that were obtained in homework-outcome relations among sources of compliance data (client, therapist, objective) were tentative due to overlapping CIs, but suggest a potential moderating effect. If confirmed by further research, the present findings would suggest that trial methods capable of assessing both quantity and quality have been an important omission in research on homework-outcome relations in CBT.