Table 3.

Frameworks for assessing strength of recommendations.

Framework	Strength	Definition
AHRQ74	High	We are very confident that the estimate of effect lies close to the true effect for this outcome. The body of evidence has few or no deficiencies.
	Moderate	We are moderately confident that the estimate of effect lies close to the true effect for this outcome. The body of evidence has some deficiencies.
	Low	We have limited confidence that the estimate of effect lies close to the true effect for this outcome. The body of evidence has major or numerous deficiencies (or both).
	Insufficient	We have no evidence, we are unable to estimate an effect, or we have not confidence in the estimate of effect for this outcome. No evidence is available, or the body of evidence has unacceptable deficiencies, precluding reaching a conclusion.
GRADE54–56	Strong	When the desirable effects of an intervention clearly outweigh the undesirable effects, or clearly do not
	Weak	When the trade-offs are less certain - either because of low quality evidence or because evidence suggests that desirable and undesirable effects are closely balanced
NCCN75	1	Based on high-level of evidence, there is uniform NCCN consensus that the intervention is appropriate
	2A	Based on lower level of evidence, there is uniform NCCN consensus that the intervention is appropriate
	2B	Based on lower level of evidence, there is NCCN consensus that the intervention is appropriate
	C	Based on high-level of evidence, there is major NCCN disagreement that the intervention is appropriate
SIGN14	A	At least 1 meta-analysis, systematic review, or RCT rated as 1++ and directly applicable to the target population or a systematic review of RCTs or a body of evidence consisting principally of studies rated as 1+, directly applicable to the target population, and demonstrating overall consistency of results
	B	A body of evidence including studies rates as 2++, directly applicable to the target population, and demonstrating overall consistency of results of extrapolated evidence from studies rated as 1++ or 1+
	C	Body of evidence including studies rated as 2+, directly applicable to the target populations, and demonstrating overall consistence of results or extrapolated evidence from studies rated as 2++
	D	Evidence level 3 or 4 or extrapolated evidence from studies rated as 2+.
USPHS/IDSA76	A	Should always be offered.
	B	Should generally be offered.
	C	Evidence for efficacy is insufficient to support a recommendation for or against, or evidence for efficacy might not outweigh adverse consequences, or cost of the approach. Optional
	D	Moderate evidence for lack of efficacy or for adverse outcome supports a recommendation against use. Should generally not be offered.
	E	Good evidence for lack of efficacy or for adverse outcome supports a recommendation against use. Should never be offered.

Abbreviations: AHRQ, Agency for Healthcare Research and Quality; GRADE, Grading of Recommendations Assessment, Development and Evaluation; NCCN, National Comprehensive Cancer Network; SIGN, Scottish Intercollegiate Guidelines Network; USPHS/IDSA, United States Public Health Service and Infectious Disease Society of America