Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
Practice Guideline
. 2017 Jul:87:4-13.
doi: 10.1016/j.jclinepi.2017.05.006. Epub 2017 May 18.

The GRADE Working Group clarifies the construct of certainty of evidence

Affiliations
Practice Guideline

The GRADE Working Group clarifies the construct of certainty of evidence

Monica Hultcrantz et al. J Clin Epidemiol. 2017 Jul.

Abstract

Objective: To clarify the grading of recommendations assessment, development and evaluation (GRADE) definition of certainty of evidence and suggest possible approaches to rating certainty of the evidence for systematic reviews, health technology assessments, and guidelines.

Study design and setting: This work was carried out by a project group within the GRADE Working Group, through brainstorming and iterative refinement of ideas, using input from workshops, presentations, and discussions at GRADE Working Group meetings to produce this document, which constitutes official GRADE guidance.

Results: Certainty of evidence is best considered as the certainty that a true effect lies on one side of a specified threshold or within a chosen range. We define possible approaches for choosing threshold or range. For guidelines, what we call a fully contextualized approach requires simultaneously considering all critical outcomes and their relative value. Less-contextualized approaches, more appropriate for systematic reviews and health technology assessments, include using specified ranges of magnitude of effect, for example, ranges of what we might consider no effect, trivial, small, moderate, or large effects.

Conclusion: It is desirable for systematic review authors, guideline panelists, and health technology assessors to specify the threshold or ranges they are using when rating the certainty in evidence.

Keywords: Certainty of evidence; GRADE; Guidelines; Health technology assessment; Systematic reviews; Thresholds.

PubMed Disclaimer

Figures

Figure 1
Figure 1. Rating certainty that the true effect lies in a particular range: an illustration from previous GRADE writings (2)

Comment in

References

    1. Balshem H, Helfand M, Schunemann HJ, Oxman AD, Kunz R, Brozek J, et al. GRADE guidelines: 3. Rating the quality of evidence. J Clin Epidemiol. 2011;64(4):401–6. - PubMed
    1. Guyatt GH, Oxman AD, Kunz R, Brozek J, Alonso-Coello P, Rind D, et al. GRADE guidelines 6. Rating the quality of evidence--imprecision. J Clin Epidemiol. 2011;64(12):1283–93. - PubMed
    1. Welch VA, Akl EA, Pottie K, Ansari MT, Briel M, Christensen R, et al. GRADE Equity Guidelines 3: Health equity considerations in rating the certainty of synthesized evidence. J Clin Epidemiol. 2017 - PMC - PubMed
    1. Schunemann HJ. Interpreting GRADE's levels of certainty or quality of the evidence: GRADE for statisticians, considering review information size or less emphasis on imprecision? J Clin Epidemiol. 2016;75:6–15. - PubMed
    1. Schunemann HJ. Guidelines 2.0: do no net harm-the future of practice guideline development in asthma and other diseases. Curr Allergy Asthma Rep. 2011;11(3):261–8. - PubMed

Publication types

MeSH terms