Evaluation of Psychotherapies from the Perspective of Quality Assurance and Quality Management

This article discusses methodological questions that may arise when routine psychotherapies are evaluated according to the principles of quality management. Examples from the Psychotherapeutic Outpatient Clinic of the University of Mainz are given to demonstrate how data should be assessed and how criteria can be defined to rate treatment outcomes. Criteria for data quality and treatment parameters are proposed. Mean differences (together with effect sizes) as well as response and remission rates should be analyzed. It is also suggested to systematically differentiate between intention-to-treat- and completer analyses, which requires that clear criteria have to be set up to classify end of treatment as either regular or dropout. Data of 493 completed treatments are used to demonstrate that completer analysis tends to overestimate treatment success. Evaluations within the frame of quality management enable an institution to develop a realistic picture of treatment quality by keeping track of quality indices over longer periods of time. This again may serve as a source for continuous improvements.