Table 2. Standardized levels of evidence used to inform recommendations reported by CPGs.

Level	Quality of Evidence	Criteria
A	High	Meta-analysis of multiple, well-designed, controlled trials; at least one systematic review of RCTs; at least one well-conducted randomized controlled trial
B	Moderate	Systematic review of cohort studies; at least one well conducted cohort study; at least one lower quality randomized controlled trial
C	Low/limited	Case series; poor quality cohort studies; a systematic review of case-control studies; other type of experimental study
D	Expert opinion/ consensus	No relevant evidence is available; recommendations based solely on expert opinion and/or consensus panel activities