Evidence Level MethodologyEvidence was classified according to the Oxford Centre for Evidence-Based Medicine criteria: Level 1a, systematic review of homogeneous randomized controlled trials; Level 1b, individual randomized controlled trial with a narrow confidence interval; Level 1c, “all-or-none” evidence; Level 2a, systematic review of homogeneous cohort studies; Level 2b, individual cohort study or low-quality randomized controlled trial, including studies with >20% attrition or loss to follow-up; Level 2c, outcomes research or etiological studies; Level 3a, systematic review of homogeneous case-control studies; Level 3b, individual case-control study; Level 4, case series or low-quality cohort or case-control studies; Level 5, expert opinion without explicit critical appraisal or based on physiology, laboratory research, or clinical experience.