Estimates of quality and reliability with the physiotherapy evidence-based database scale to assess the methodology of randomized controlled trials of pharmacological and nonpharmacological interventions

Background and Purpose. Systematic reviews and meta-analyses often include an evaluation of the methodological quality of the individual studies that have been included, and are usually conducted by at least 2 individuals. The objective of this study was to assess the methodological quality and reliability of a series of randomized controlled trials (RCTs) of both pharmacological and nonpharmacological interventions by use of the 10-item Physiotherapy Evidence-Based Database (PEDro) Scale. Methods. Two abstractors independently reviewed 81 RCTs assessing a variety of interventions. The Cohen kappa statistic and the intraclass correlation coefficient (ICC) were used to assess agreement between abstractors. Results. The average total PEDro scores were 5.94 (SD=1.43) for all studies combined, 6.88 (SD=1.2) for pharmacological studies, and 5.29 (SD=1.26) for nonpharmacological studies. The median score for pharmacological studies was significantly higher than that for nonpharmacological studies (7 versus 5). Pair-wise kappa scores ranged from a low of 452 for concealed allocation among drug trials to perfect agreement (1.00) for randomization and reporting of results from between-group comparisons. The ICCs associated with the cumulative PEDro score were .91 (95% confidence interval [CI] = .83-.94) for all studies, .89 (95% CI = .78-.95) for pharmacological studies, and .91 (95% CI = .84-.952) for nonpharmacological studies. Discussion and Conclusion. The methodological quality for pharmacological interventions was significantly,higher than that for nonpharmacological interventions. There was good agreement between raters at an individual item level and in total PEDro scores. A lack of reporting clarity, poor organization of the report, or the failure to include salient details contributed to less-than-perfect agreement between raters.