title: Applying a novel statistical method to advance the personalized treatment of anxiety disorders: A composite moderator of comparative drop-out from CBT and ACT.
abstract: No prior studies have examined moderators of dropout between distinct treatments for anxiety disorders. This study applied a novel statistical approach for examining moderators of dropout from traditional cognitive behavioral therapy (CBT) and acceptance and commitment therapy (ACT).
  
  
  
  We combined data from two randomized controlled trials (N = 208) comparing CBT and ACT for patients with DSM-IV anxiety disorders. Adapting Kraemer's method for constructing and evaluating composite moderators (2013), 26 variables were examined for individual effect sizes. Forward-stepwise regression combined with k-fold cross validation was used to identify a model to predict treatment dropout.
  
  
  
  Four baseline variables comprised the final composite moderator: self-reported degree of control over internal anxiety, current psychiatric medication use, religiosity, and endurance in a voluntary hyperventilation stressor. This composite moderator predicted differential dropout from ACT vs. CBT with a medium effect size (r = 0.28), and had a significantly larger effect size than any individual moderator.
  
  
  
  Findings reveal that specific patient profiles predict differential dropout from ACT vs. CBT for anxiety disorders. In the first investigation of a composite moderator with a dichotomous outcome, findings also support the superiority of composite over individual moderators.
authors.affiliation: University of California, Los Angeles, Department of Psychology, 1285 Franz Hall, Box 951563, Los Angeles, CA 90095-1563, USA. Electronic address: aniles@ucla.edu.
authors.forename: Andrea N
authors.initials: AN
authors.lastname: Niles
authors.affiliation: University of California, Los Angeles, Department of Psychiatry and Biobehavioral Science, 760 Westwood Plaza, Los Angeles, CA 90095, USA.
authors.forename: Kate B
authors.initials: KB
authors.lastname: Wolitzky-Taylor
authors.affiliation: University of Colorado Boulder, Department of Psychology, Muenzinger D244, 345 UCB, Boulder, CO 80309-0345, USA.
authors.forename: Joanna J
authors.initials: JJ
authors.lastname: Arch
authors.affiliation: University of California, Los Angeles, Department of Psychology, 1285 Franz Hall, Box 951563, Los Angeles, CA 90095-1563, USA; University of California, Los Angeles, Department of Psychiatry and Biobehavioral Science, 760 Westwood Plaza, Los Angeles, CA 90095, USA.
authors.forename: Michelle G
authors.initials: MG
authors.lastname: Craske
mesh_terms: D064869:Acceptance and Commitment Therapy; D000328:Adult; D001008:Anxiety Disorders / Q000628:therapy*; D015928:Cognitive Behavioral Therapy; D005260:Female; D006801:Humans; D008297:Male; D008960:Models, Psychological; D010352:Patient Dropouts / Q000706:statistics & numerical data*; D016896:Treatment Outcome; D055815:Young Adult
keywords: Anxiety disorders; Attrition; Behavioral therapy; Moderators; Personalized medicine