Interrater Reliability of the Modified Jadad Quality Scale for Systematic Reviews of Alzheimer’s Disease Drug Trials

Abstract

Drug therapies for Alzheimer's disease (AD) have been evaluated in clinical trials over the past 2 decades. Systematic reviews of AD drug trials can shed more light on the efficacy of pharmaceutical interventions. The modified Jadad scale can be used to assess the quality of trial reports that are candidates for inclusion in these systematic reviews. The interrater reliability of the modified Jadad scale was examined during such a review. Three blinded reviewers rated the quality of 42 AD drug trial reports: the intraclass correlation coefficient was 0.90. The modified Jadad scale appears to be a useful tool for AD research because of the very good interrater reliability. Also, it is composed of items that are well suited to the specific disease characteristics of AD. Further research should focus on the validity of this instrument.