Each study was reviewed by 2 reviewers who assigned one of the following ratings: evidence A, randomized clinical trials; evidence B, cohort or case-control studies; evidence C, case reports or flawed

The gap

Consensus across the literature

Supporting evidence — 3 representative gaps

• Effectiveness of cupping therapy for musculoskeletal pain: an umbrella review (2024) · doi

  Among the critical items, all reviews failed to present a list of excluded trials, four reviews did not consider the risk of bias when presenting or discussing their results, three reviews did not use adequate methods for the meta-analysis, the impact of publication bias was not investigated in three reviews, and the absence of a planned protocol to guide the review was noted in two reviews.

  Keywords: reviews bias three among critical items failed present list excluded trials four consider risk presenting
• A systematic review of implant outcomes in treated periodontitis patients (2015) · doi

  The strength of the evidence was limited by the heterogeneity of the included studies in terms of study design, population, therapy, unit of analysis, inconsistent definition of baselines and outcomes, as well as by the inadequate reporting of statistical analysis and accounting for confounding factors; thus, meta-analysis could not be performed.

  Keywords: strength evidence limited heterogeneity included terms design population therapy unit inconsistent definition baselines outcomes well
• Are Lifestyle Measures Effective in Patients With Gastroesophageal Reflux Disease? (2006) · doi

  Each study was reviewed by 2 reviewers who assigned one of the following ratings: evidence A, randomized clinical trials; evidence B, cohort or case-control studies; evidence C, case reports or flawed clinical trials; evidence D, investigator experience; or evidence E, insufficient information.

  Keywords: evidence clinical trials case reviewed reviewers assigned following ratings randomized cohort control reports flawed investigator