Table 5. Strength of Recommendation and Quality of Evidence
Category/Grade Definition
Recommendation
S - Strong Clear desirable or undesirable effects
W - Weak Desirable and undesirable effects closely balanced or uncertain
Quality of Evidence
H - High Consistent evidence from well-performed RCTs or exceptionally
strong evidence from unbiased observational studies
M - Moderate Evidence from RCTs with important limitations or exceptionally
strong evidence from unbiased observational studies
L - Low Evidence for at least one critical outcome from observational
studies, RCTs with serious flaws, or indirect evidence
VL - Very low Evidence for at least one critical outcome from unsystematic clinical
observations or very indirect evidence
GRADE Implication Comment
S-H Applies to most patients in most
circumstances
Further research is unlikely to
change estimate
S-M Further research may change
estimate
S-L
S-VL Estimate of effect for at least
one critical outcome is very
uncertain
W-H e best action may differ
depending on circumstances or
patients or societal values
Further research is unlikely to
change estimate
W-M Alternative approaches likely
to be better for some patients
under some circumstances
Further research may change
estimate
W-L Other alternatives may be
equally reasonable
W-VL 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/
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