Grading Evidence

"Evidence Blocks"

A system in oncology (from the National Comprehensive Cancer Network) for evaluating new chemotherapies. See ARTICLE.

(tip o' the hat to Kareem Royes for this one...)

See this article outlining the Strength of Recommendation Taxonomy for Primary Care (SORT-PC)

The GRADE system (gradeworkinggroup.org) evaluates the strength of the evidence found in the research literature about a clinical question.

GRADE is used in many contemporary guidelines to increase the "evidence-based-ness" of the guideline.

• It helps authors of guidelines understand the evidence they use to make clinical recommendations

• It helps readers and users of guidelines understand the strength of the evidence behind the clinical recommendations.

GRADE is a system for assigning both a "level of evidence" and a "grade (strength) of recommendation".

While the definitions of these terms aren't strictly codified, there is a general understanding that:

• level of evidence refers to the appraisal of a SINGLE study report - its validity, results, applicability, etc.

  • in GRADE, this is high, moderate, low, or very low

• grade (strength) of recommendation refers to the quality of evidence behind a clinical recommendation

  • in GRADE, this is both the validity of the evidence (which gives us an idea of the certainty of the benefit/risk) and the magnitude of the evidence (the benefit vs. the harm)