Scales to Assess the Quality of Randomized Controlled Trials: A Systematic Review

Background and Purpose: The methodological quality of randomized controlled trials (RCTs) is commonly evaluated in order to assess the risk of biased estimates of treatment effects. The purpose of this systematic review was to identify scales used to evaluate the methodological quality of RCTs in health care research and summarize the content, construction, development, and psychometric properties of these scales. Methods: Extensive electronic database searches, along with a manual search, were performed. Results: One hundred five relevant studies were identified. They accounted for 21 scales and their modifications. The majority of scales had not been rigorously developed or tested for validity and reliability. The Jadad Scale presented the best validity and reliability evidence; however, its validity for physical therapy trials has not been supported. Discussion and Conclusion: Many scales are used to evaluate the methodological quality of RCTs, but most of these scales have not been adequately developed and have not been adequately tested for validity and reliability. A valid and reliable scale for the assessment of the methodological quality of physical therapy trials needs to be developed.