The validity (convergent and construct) and inter-rater reliability of the PEDro scale has been evaluated for pharmaceutical trials. 53 randomised placebo controlled trials evaluating any pain medication for chronic spinal pain or osteoarthritis were assessed by two raters. Convergent validity was evaluated by correlating the total PEDro score with the summary score of the Cochrane Back and Neck Group risk of bias tool. Construct validity was tested using a linear regression analysis to determine the degree to which the total PEDro score was associated with treatment effect sizes, journal impact factor and the summary score for the Cochrane Back and Neck Group risk of bias tool. The correlation between the total PEDro score and summary score for the Cochrane Back and Neck Group risk of bias tool was 0.83 (95% CI 0.76 to 0.88), indicating strong convergence. The total PEDro score was inversely associated with effect sizes, significantly associated with the summary score for the Cochrane Back and Neck Group risk of bias tool, and not associated with the journal impact factor. The inter-rater reliability for each item of the PEDro scale and Cochrane Back and Neck Group risk of bias tool was at least substantial for most items (Prevalence and Bias Adjusted Kappa > 0.60). The Intraclass Correlation Coefficient was 0.80 (95% CI 0.68 to 0.88) for the total PEDro score and 0.81 (95% CI 0.69 to 0.88) for the Cochrane Back and Neck Group risk of bias tool summary score. There was evidence for the convergent and construct validity for the PEDro scale. Both the PEDro scale and Cochrane Back and Neck Group risk of bias tool have acceptably high inter-rater reliability.

Yamato et al. The PEDro scale had acceptably high convergent validity, construct validity and inter-rater reliability in evaluating methodological quality of pharmaceutical trials. J Clin Epidemiol 2017;86:176-81