Key Points
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 ≥1 critical outcome from observational studies, from
RCTs with serious flaws or from indirect evidence
VL – Very low Evidence for ≥1 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 e 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
RCTs, randomized controlled trials.
For the complete Grading of Recommendations Assessment, Development and Evaluation
(GRADE) Strength of Recommendations and Quality of the Evidence Table, visit the IDSA
website: http://www.idsociety.org/Guidelines_Other/.
