Table 13. Strength of Recommendation and Quality of Evidence
Category/Grade
Definition
Recommendation
SR - Strong
Clear desirable or undesirable effects
WR - 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 moderately
strong evidence from unbiased observational studies
L - Low
Evidence for ≥ one critical outcome from observational studies,
from RCTs with serious flaws or from indirect evidence
VL - Very low
Evidence for ≥ one critical outcome from unsystematic clinical
observations or very indirect evidence
GRADE
Implication
Comment
SR-H
Applies to most patients in most
circumstances
Further research is unlikely to
change estimate
SR-M
Further research may change
estimate
SR-L
SR-VL
Estimate of effect for at least
one critical outcome is very
uncertain
WR-H
The best action may differ
depending on circumstances or
patients or societal values
Further research is unlikely to
change estimate
WR-M
Alternative approaches likely
to be better for some patients
under some circumstances
Further research may change
estimate
WR-L
Other alternatives may be
equally reasonable
WR-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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