Grade of Recommendation	Strength of Evidence
A Strong evidence	A preponderance of level I and or level II studies support the recommendation. This must include at least 1 level 1 study
B Moderate evidence	A single high-quality randomized controlled trial or a preponderance of level II studies support the recommendation
C Weak evidence	A single level II study or a preponderance of level III and IV studies, including statements of consensus by content experts, support the recommendation
D Conflicting evidence	Higher-quality studies conducted on this topic disagree with respect to their conclusions. The recommendation is based on these conflicting studies
E Theoretical/foundational evidence	A preponderance of evidence from animal or cadaver studies, from conceptual models/ principles, or from basic science/bench research support this conclusion
F Expert opinion	Best practice based on the clinical experience of the guidelines development team