title: Are Trials of Computerized Therapy Generalizable? A Multidimensional Meta-analysis.
abstract: Previous meta-analyses have established that computerized cognitive behavioral therapy (cCBT) is an effective, acceptable, and efficient method of delivering treatment for anxiety and depression. However, the potential generalizability of these conclusions to nonresearch settings has not yet been investigated.
  
  
  
  We conducted a multidimensional meta-analysis of randomized controlled trials of cCBT for anxiety and/or depressive disorders quantifying generalizability by examining the relationship between participant exclusion and treatment outcome. Thirty-six trials of cCBT were identified through systematic searches in six databases. The number of exclusion criteria and exclusion rate served as indices of participant exclusion. Outcome variables included between- and within-group effect sizes in addition to rates of clinically significant improvement.
  
  
  
  Analyses were performed for all studies, depression studies (n = 11), and anxiety studies (n = 23). Pooling across all studies, we found a between-group effect size of 0.85 (95% confidence interval, 0.77-0.94). The mean number of exclusionary criteria was 12 (range, 2-24), and the mean exclusion rate was 0.49 (range, 0.08-0.92). Risk for suicide was the most common criterion for exclusion. Correlation analyses revealed a large relationship between number of exclusion criteria and proportion clinically changed in the treatment group for anxiety studies (r = 0.70). Results provide evidence for the limited effectiveness of cCBT for anxiety disorders in nonresearch samples.
  
  
  
  As computerized therapy is developed to address barriers to dissemination, future trials should examine the effectiveness of cCBT for anxiety for patients with more complex clinical presentations.
authors.affiliation: Behavioral Research and Therapy Clinics, Department of Clinical Psychology, University of Washington , Seattle, Washington.
authors.forename: Chelsey R
authors.initials: CR
authors.lastname: Wilks
authors.affiliation: Behavioral Research and Therapy Clinics, Department of Clinical Psychology, University of Washington , Seattle, Washington.
authors.forename: Garret G
authors.initials: GG
authors.lastname: Zieve
authors.affiliation: Behavioral Research and Therapy Clinics, Department of Clinical Psychology, University of Washington , Seattle, Washington.
authors.forename: Hannah K
authors.initials: HK
authors.lastname: Lessing
mesh_terms: D001008:Anxiety Disorders / Q000628:therapy*; D015928:Cognitive Behavioral Therapy / Q000379:methods*; D003866:Depressive Disorder / Q000628:therapy*; D020407:Internet; D016032:Randomized Controlled Trials as Topic; D017216:Telemedicine / Q000379:methods*
keywords: cognitive behavioral therapy; computerized psychotherapy; e-health; exclusionary criteria; mental health; meta-analysis