To the Editor Barlow and colleagues1 compared a unified cognitive behavior therapy protocol with single-disorder cognitive behavior therapy protocols in anxiety disorders. Unified protocols for broader classes of disorders represent a promising approach. However, several issues need to be clarified.
First, in the study protocol, the authors1 listed 4 measures as primary outcomes without defining 1 of them as primary. Numerous primary outcomes imply several problems, including ambiguity of results, problems for power analysis, and type I error inflation.2 In the article, however, the authors specify only Anxiety Disorders Interview Schedule clinical severity ratings as the primary outcome.1