Table 1.

Definitions for the class of recommendation and level of evidence in this consensus.

Class of recommendation		Level of evidence
Strong recommendation	>90% agreement of expert opinions	A	At least one randomized controlled trial or one high-quality meta-analysis
Recommendation	70–90% agreement of expert opinions	B	At least one randomized observational study, specific subgroup analysis, and large-scale observational study
Moderate recommendation	50–70% agreement of expert opinions	C	Nonrandomized controlled trials or expert opinions
No recommendation	<50% of expert opinions