Table 2.

Grading of Recommendations Assessment, Development and Evaluation (GRADE) Working Group Criteria⁸⁶

GRADE OF RECOMMENDATION		STRENGTH OF EVIDENCE
A	Strong	A preponderance of level I and/or level II studies support the recommendation. Must include ≥ 1 level I study.
B	Moderate	A single high-quality randomized controlled trial or a preponderance of level II studies support the recommendation.
C	Weak	A single level II study or a preponderance of level III and level IV studies including statements of consensus by content experts support the recommendation.
D	Conflicting	Higher-quality studies conducted on this topic disagree with respect to their conclusions. The recommendation is based on these conflicting studies.
E	Theoretical/Foundational	A preponderance of evidence from animal or cadaver studies, from conceptual models/principles, or from basic sciences/bench research support this conclusion.
F	Expert Opinion	Best practice based on the clinical experience of the guidelines development team.