Grading the Quality of Evidence

Grading evidence is a systematic, transparent process of reviewing and assessing the quality of evidence available in a body or research. The end result of the grading process is an evidence summary that can be used by guidelines developers and policy makers.

Articles on Grading the Quality of Evidence

  1. Dijkers, M. (2013). Introducing GRADE: a systematic approach to rating evidence in systematic reviews and to guideline development. KT Update, 1(5).
  2. Porritt, K., Gomersall, J., & Lockwood, C. (2014). JBI's Systematic Reviews: Study selection and critical appraisal. American Journal of Nursing, 114,(6), 47-52.

Evidence Grading Protocols

  1. Grading of Recommendations Assessment, Development and Evaluation (GRADE):  GRADE is a systematic approach to evaluating the quality of evidence in a systematic review. It is attempting to be a single system of evidence grading that can accommodate a wide range of systematic reviews. Although, it was designed initially to focus on reviews of interventions, there is much ongoing work adapting it for prognostic and observational reviews.
  2. Prediction study risk of bias assessment tool (PROBAST). A tool facilitating quality assessment for prognostic and diagnostic prediction modelling studies. In development.
  3. Quality Assessment of Diagnostic Accuracy Studies (QUADAS-2)
    1. Whiting, P. F., Rutjes, A. W. F., Westwood, M. E., Mallet, S. Deeks, J. J., Reitsma, J. B., Leeflang, M. M. G., Sterne, J. A. C. Bossuyt, P. M. M., & the QUADAS-2 Group. (2011). QUADAS-2: A Revised Tool for the Quality Assessment of Diagnostic Accuracy Studies. Annals of Internal Medicine, 155(8), 529-536. A tool for systematic reviews of diagnostic accuracy studies.
  4. Quality In Prognosis Studies tool (QUIPS)
    1. Hayden, J. A., van der Windt, D. A., Cartwright, J. L., Cote, P., & Bombardier, C. (2013). Assessing Bias in Studies of Prognostic Factors. Research and Reporting Methods, (158(4), 280-286.

Guidelines for Writing Different Types of Research Studies

Although not directly relevant to the grading of evidence, it can be useful to review the guidelines that have been developed for writing different types of research studies when embarking on a grading activity. Review of these guidelines can help you understand what you would hope to see in a study of a certain type and how that information would ideally be reported.

  1. EQUATOR: Enhancing the Quality and Transparency of Health Research. The EQUATOR Network works to improve the reliability and value of medical research literature by promoting transparent and accurate reporting of research studies. Their website highlights the guidelines below as well as others.
  2. CONSORT: Consolidated Standards of Reporting Trials. CONSORT encompasses various initiatives developed by the CONSORT Group to alleviate the problems arising from inadequate reporting of randomized controlled trials.
  3. Quality of Reporting of Meta-Analyses (QUORUM). A checklist guiding reporting of meta-analyses.
  4. The Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) Statement: guidelines for reporting observational studies. Guidance about how to report observational studies.
  5. Transparent Reporting of Multivariable Prediction Model for Individual Prognosis or Diagnosis Initiative (TRIPOD). An evidence-based, minimum set of recommendations for reporting prediction modeling studies in biomedical sciences.

Grading Software

  1. GRADEPro: GRADEpro is the software used to create Summary of Findings (SoF) tables in Cochrane systematic reviews.

Back to: Resources for Conducting Systematic Reviews