Fig. 2From: The risk of bias in randomized controlled trials in otorhinolaryngology: hardly any improvement since 1950 a-h Development of RoB per item per time stratum. a) random sequence generation, b) allocation concealment, c) blinding of participants and personnel, d) blinding of outcome assessment, e) blinding, f) selective reporting, g) incomplete outcome data, and h) other bias. X-axis: time strata (number of assessments). Y-axis: proportion of articles that had low (green line), unclear (yellow line) or high (red line) RoBBack to article page