1+	High-quality RCTs＊ and their MA/SR
1	Other RCTs and their MA/SR
2	Prospective cohort studies, their MA/SR, (predefined) RCT subanalysis
3	Non-randomized controlled trials, before-and-after studies, retrospective cohort studies, case-control studies, and their MA/SR and RCT post hoc subanalysis
4	Cross-sectional studies, case series
Consensus	By consensus of the supervisory committee members and the members who prepared the report

RCT: randomized controlled trial, MA: meta-analysis, SR: systematic review

^＊A high-quality RCT is defined as (1) large number of subjects, (2) double-blind, independent assessment, (3) high follow-up rate (low dropout rate), (3) low protocol deviation, (4) clear random allocation method, etc.