Conclusiveness of Cochrane Reviews in physiotherapy: a systematic search and analytical review.

Numerous Cochrane Reviews (CRs) in the field of physiotherapy have been published, but their conclusiveness has not been investigated. The purpose of this study was to provide an overview and describe the conclusiveness of evidence from CRs regarding physiotherapy. We conducted a systematic search using the Cochrane Database of Systematic Reviews in the Cochrane Library from 2008 through 2017 in the field of physiotherapy, the Physical Rehabilitation Evidence Database, and the CRs list on the Cochrane Rehabilitation website. Reviewers extracted the following data: year of publication, editorial group, number of articles meeting the criteria, number of patients enrolled, conclusiveness, and need for additional studies. Linear regression was used to determine whether the percentage of conclusive reviews was affected by the year of publication. Reviewers found 283 CRs in the field of physiotherapy, and only 16 (5.7%) of which were conclusive. The number of trials and participants enrolled in conclusive reviews were significantly higher than those in inconclusive reviews (P<0.001). The percentage of conclusive reviews was significantly correlated with year of publication (P=0.03). Almost all reviews recognized the need for additional studies. Most CRs in physiotherapy are inconclusive, and most emphasize the need for further research. The ability of a Cochrane Review to reach a conclusion is affected by the cumulative patient sample size and number of trials included in the analysis.