Identifying and addressing conflicting results across multiple discordant systematic reviews on the same question: protocol for a replication study of the Jadad algorithm

Abstract

IntroductionAn increasing growth of systematic reviews (SRs) presents notable challenges for decision-makers seeking to answer clinical questions. In 1997, an algorithm was created by Jadad to assess discordance in results across SRs on the same question. Our study aims to (1) replicate assessments done in a sample of studies using the Jadad algorithm to determine if the same SR would have been chosen, (2) evaluate the Jadad algorithm in terms of utility, efficiency and comprehensiveness, and (3) describe how authors address discordance in results across multiple SRs.Methods and analysisWe will use a database of 1218 overviews (2000–2020) created from a bibliometric study as the basis of our search for studies assessing discordance (called discordant reviews). This bibliometric study searched MEDLINE (Ovid), Epistemonikos and Cochrane Database of Systematic Reviews for overviews. We will include any study using Jadad (1997) or another method to assess discordance. The first 30 studies screened at the full-text stage by two independent reviewers will be included. We will replicate the authors’ Jadad assessments. We will compare our outcomes qualitatively and evaluate the differences between our Jadad assessment of discordance and the authors’ assessment.Ethics and disseminationNo ethics approval was required as no human subjects were involved. In addition to publishing in an open-access journal, we will disseminate evidence summaries through formal and informal conferences, academic websites, and across social media platforms. This is the first study to comprehensively evaluate and replicate Jadad algorithm assessments of discordance across multiple SRs.

Evidence-based health policy in Germany: lack of communication and coordination between academia and health authorities?

“…However, overlap leaves SR users with two major challenges. First, SRs can reach different conclusions [10][11][12]. Second, the reporting quality as well as the methodological quality of SRs still leaves a lot of room for improvement (e.g., [13]).…”

Can a replication revolution resolve the duplication crisis in systematic reviews?

“…Second, replication may resolve confusion related to discordant findings in previous reviews. There are countless examples of multiple systematic reviews on the same topic generating conflicting results and conclusions, thereby creating confusion rather than providing direction for knowledge users and decision-makers 20. In some cases, careful examination of the existing systematic reviews to identify differences in the scope of the research question, methods, interpretation of otherwise similar results or computational errors might allow us to explain the discordance.…”