Risk of bias and methodological appraisal practices in systematic reviews published in anaesthetic journals: A meta-epidemiological study

B. N. Detweiler, L. E. Kollmorgen, B. A. Umberham, R. J. Hedin, B. M. Vassar

Research output: Contribution to journalReview article

9 Scopus citations


The validity of primary study results included in systematic reviews plays an important role in drawing conclusions about intervention effectiveness and carries implications for clinical decision-making. We evaluated the prevalence of methodological quality and risk of bias assessments in systematic reviews published in the five highest-ranked anaesthesia journals since 2007. The initial PubMed search yielded 315 citations, and our final sample after screening consisted of 207 systematic reviews. One hundred and seventy-four reviews conducted methodological quality/risk of bias analyses. The Jadad scale was most frequently used. Forty-four of the 83 reviews that included high risk of bias studies re-analysed their data omitting these trials: 20 showed differences in pooled effect estimates. Reviews containing a greater number of primary studies evaluated quality less frequently than smaller reviews. Overall, the majority of reviews evaluated bias; however, many applied questionable methods. Given the potential effects of bias on summary outcomes, greater attention is warranted.

Original languageEnglish
Pages (from-to)955-968
Number of pages14
Issue number8
Publication statusPublished - 1 Aug 2016



  • Cochrane
  • Meta-analysis
  • Research quality
  • Risk of bias
  • Systematic review

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