Table 9. Strength of Recommendation and Quality of Evidence Category/Grade Definition Recommendation SR - Strong WR - Weak
Clear desirable or undesirable effects Desirable and undesirable effects closely balanced or uncertain
Quality of Evidence H - High
M - Moderate L - Low VL - Very low
GRADE SR-H
SR-M
SR-L SR-VL
WR-H WR-M WR-L WR-VL
Estimate of effect for at least one critical outcome is very uncertain
The best action may differ depending on circumstances or patients or societal values
Alternative approaches likely to be better for some patients under some circumstances
Other alternatives may be equally reasonable
Further research is unlikely to change estimate
Further research may change estimate
Any estimate of effect, for at least one critical outcome, is very uncertain
For the complete GRADE Strength of Recommendations and Quality of the Evidence Table, visit the IDSA website: http://www.idsociety.org/Guidelines_Other/
Consistent evidence from well-performed RCTs or exceptionally strong evidence from unbiased observational studies
Evidence from RCTs with important limitations or moderately strong evidence from unbiased observational studies
Evidence for ≥ one critical outcome from observational studies, from RCTs with serious flaws or from indirect evidence
Evidence for ≥ one critical outcome from unsystematic clinical observations or very indirect evidence
Implication
Applies to most patients in most circumstances
Comment
Further research is unlikely to change estimate
Further research may change estimate
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