False individual patient data and zombie randomised controlled trials submitted to Anaesthesia.

Concerned that studies contain false data, I analysed the baseline summary data of randomised controlled trials when they were submitted to Anaesthesia from February 2017 to March 2020. I categorised trials with false data as 'zombie' if I thought that the trial was fatally flawed. I analysed 526 submitted trials: 73 (14%) had false data and 43 (8%) I categorised zombie. Individual patient data increased detection of false data and categorisation of trials as zombie compared with trials without individual patient data: 67/153 (44%) false vs. 6/373 (2%) false; and 40/153 (26%) zombie vs. 3/373 (1%) zombie, respectively. The analysis of individual patient data was independently associated with false data (odds ratio (95% credible interval) 47 (17-144); p = 1.3 × 10 ) and zombie trials (odds ratio (95% credible interval) 79 (19-384); p = 5.6 × 10 ). Authors from five countries submitted the majority of trials: China 96 (18%); South Korea 87 (17%); India 44 (8%); Japan 35 (7%); and Egypt 32 (6%). I identified trials with false data and in turn categorised trials zombie for: 27/56 (48%) and 20/56 (36%) Chinese trials; 7/22 (32%) and 1/22 (5%) South Korean trials; 8/13 (62%) and 6/13 (46%) Indian trials; 2/11 (18%) and 2/11 (18%) Japanese trials; and 9/10 (90%) and 7/10 (70%) Egyptian trials, respectively. The review of individual patient data of submitted randomised controlled trials revealed false data in 44%. I think journals should assume that all submitted papers are potentially flawed and editors should review individual patient data before publishing randomised controlled trials.