TABLE 1. Level of evidence and study design.

Level of evidence	Study design
I	Systematic reviews or meta-analyses of randomized clinical trials.
II	Well-designed randomized controlled clinical trial.
III	Well-designed, non-randomized controlled clinical trial.
IV	Cohort study, case-control study, well-designed cross-sectional study.
V	Systematic review of qualitative and descriptive studies.
VI	Unique descriptive or qualitative study.
VII	Expert opinion and/or expert report.

Source: Author‘s own work (2024).