Levels of evidence
| Strong evidence | Consistent (ie, when ≥75% of the trials report the same findings) positive (significant) findings within multiple randomised clinical trials (RCTs) of good quality |
| Moderate evidence | Consistent positive (significant) findings within multiple RCTs of low quality and/or one RCT of good quality |
| Limited evidence | Positive (significant) findings within one RCT of low quality |
| Conflicting evidence | Conflicting (significant) findings in the RCTs (<75% of the studies reported consistent findings) |
| No evidence | RCT(s) available, but no (significant) differences between the intervention and control groups were reported |