Rating the quality of trials in systematic reviews of physical therapy interventions

Physical therapists seeking to use evidence to guide their practice may have limited time to read research reports. One way to reduce the time required to identify and read about the research that is relevant to a particular clinical question is to read a systematic review that summarizes multiple studies. This paper explains the process that is used to conduct systematic reviews, which includes the establishment of a protocol, comprehensive searching, appraisal of the quality of the included studies, data extraction and metaanalysis, and consideration of the clinical and research implications of the findings. We also consider how the reader of a systematic review can determine whether the review is likely to provide an unbiased (believable) estimate of the treatment effect. A systematic review of randomized trials of a cardiopulmonary physical therapy intervention is used as an example. The issue of appraisal of quality is then discussed further, with a demonstration of how one validated tool for quality appraisal-the PEDro scale-can be used to evaluate a randomized trial in cardiopulmonary physical therapy.