Corrigendum to “Impact of active placebo controls on estimated drug effects in randomized trials: a meta-epidemiological study” [Journal of Clinical Epidemiology 188 (2025) 111998]

The authors regret that 7 trials were erroneously excluded from 2 meta-analyses of benefit during overlap removal and that another meta-analysis of attrition was erroneously included as a co-intervention meta-analysis.Re-adding those trials and removing that meta-analysis leads to small changes in the pooled estimates for benefit and for co-interventions and leads to two heterogeneity analyses becoming statistically significant, although we interpret these with caution.The abstract text for results should be: ''Results: We included 67 reviews with 122 meta-analyses of 1674 trials.The pooled ROR of benefit was 1.00 (95% CI 0.79-1.28,I 2 = 48%, 2 = 0.35, 95% prediction interval 0.31-3.26,64 meta-analyses, 734 trials).The result did not change much in sensitivity analyses, and heterogeneity analyses were inconclusive.The results of secondary analyses were imprecise.''The plain language summary text on results should be: ''We found that in trials using regular placebo controls, the experimental drug effect was the same as in similar trials with active placebo controls, on average, but there was considerable variation between meta-analyses.The result could be a chance finding and, due to random variation, was compatible with both a 21% exaggeration and 28% underestimation of effect (when measured as odds ratio).''