Earlier quantitative and qualitative reviews that were most closely related to our study include the studies by Baer (2003) and Toneatto and Nguyen (2007). Baer (2003) reported an average pre-post effect size of d = 0.59 based on 15 studies that were weighed by sample size. However, the dependent variables were not restricted to anxiety and depression measures but were based on a range of symptom measures, including measures of stress, pain, memory, and binge eating. Therefore, it is difficult to directly compare the effect size estimates found in our study with those reported by Baer.
