What criteria were used to rate the quality of evidence that supports the recommendations?
Recommendation strength communicates the importance of adherence to a recommendation and is based on both the quality of the evidence and the magnitude of anticipated benefits and harms. Quality of individual studies was graded in a three-tiered grading system (see Table 10). Quality of evidence and strength of recommendations were graded following the GRADE approach (Tables 12 and 14). The Work Group could provide general guidance in unngraded statements.