Study type | Study quality assessments | LoE | Grade of recommendation (based on overall LoE, considering balance of clinical practice information and evidence) | ||||
Statistical analyses and patient follow-up assessment | Allocation concealment* | Jadad scores | Additional assessment of overall study quality required to judge LoE | ||||
Systematic review with homogeneous results | NA | NA | NA | NA | 1 | A | |
RCT | Statistics reported and >80% follow-up | AND | A | (1–5) | NA | 1 | A (based on two or more studies or a single, large, well-designed study) |
OR | |||||||
B | (3–5) | NA | |||||
OR | |||||||
B | (1–2) | Yes | |||||
RCT | Statistics not reported or questionable or <80% follow-up | AND/OR | B | (1–2) | Yes | 2 | B (or extrapolation from one procedure-specific LoE 1 study) |
OR | |||||||
C | (1–5) | NA | |||||
OR | |||||||
D | 1–5) | NA | |||||
Non-systematic review, cohort study, case study (eg, adverse effects) | NA | NA | 3 | C | |||
Clinical practice information (expert opinion); inconsistent evidence | NA | NA | 4 | D |
*Allocation concealment is given as A adequate, B unclear, C inadequate, and D not used.
LoE, level of evidence; NA, not applicable; RCT, randomized controlled trial.