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Health Research Reporting Guidelines, Study Execution Manuals, Critical Appraisal, Risk of Bias, & Non-reporting Biases

What is meant by Certainy of Evidence?

What is Certainty of Evidence?

"The certainty (or quality) of evidence is the extent to which we can be confident that what the research tells us about a particular treatment effect is likely to be accurate. Concerns about factors such as bias can reduce the certainty of the evidence. Evidence may be of high certainty; moderate certainty; low certainty or very-low certainty. " (Certainty of Evidence, Cochrane UK)

In a systematic review, assessing for certainty of evidence is the last step of Methods and Results. For interventions, GRADE (Grading of Recommendations, Assessment, Development and Evaluation) has been the preferred tool by many although, like any assessment tool, it does require training.

For more information on this step, see the Cochrane Handbook, Chapter 14: Completing ‘Summary of findings’ tables and grading the certainty of the evidence and Chapter 15: Chapter 15: Interpreting results and drawing conclusions.

Assessment tools

GRADE (Grading of Recommendations Assessment, Development, and Evaluation)

Produced by: The GRADE Working Group
About: The Grading of Recommendations Assessment, Development and Evaluation (short GRADE) is a common, sensible and transparent approach to grading quality (or certainty) of evidence and strength of recommendations.

GRADE Handbook

  • The GRADE handbook describes the process of rating the quality of the best available evidence and developing health care recommendations following the approach proposed by the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) Working Group (www.gradeworkinggroup.org).

QoE-SPEO: Quality of Evidence in Studies estimating Prevalence of Exposure to Occupational risk factors (Open access)

Development supported by: World Health Organization/International Labour Organization
About: "We present QoE-SPEO as an approach for assessing quality of evidence in prevalence studies of exposure to occupational risk factors.... While the approach requires further testing and development, it makes steps towards filling an identified gap, and progress made so far can be used to inform future work in this area."