Assessing methodological quality of randomized and quasi-experimental trials: a summary of stuttering treatment research.

The purpose of this study is to provide a detailed analysis of the methodological quality of experimental and quasi-experimental group designed studies in the area of stuttering intervention. A total of 23 randomized controlled trials (RCT) and quasi-experimental studies of treatment in the area of stuttering were identified and retrieved from an electronic search of nine databases and 13 individual journals. Using the Downs and Black Checklist each study was coded for reporting, external validity, internal validity, and internal validity confounding. Results of the coding indicated that while overall reporting was reasonably complete, the quality of the external and internal validity scores was found to be substantively incomplete. This lack of clarity and completeness of reporting issues related to the external and internal validity makes the interpretation of the findings of individual study results problematic and seriously effects the replicability of the individual study. Implications of these findings are suggested for both researchers and clinicians.