Table 2

Definition of the quality of evidence (QoE)

StrongEvidence from at least one properly designed RCT
ModerateEvidence from at least one well-designed clinical trial, without randomisation; from cohort or case–control analytic studies (preferably from more than one centre); from multiple time series
LowEvidence from opinions of respected authorities, based on clinical experience, descriptive case studies or reports of expert committees
  • RCT, randomised controlled trial.