Data integrity of 35 randomised controlled trials in women’ health

While updating a systematic review on the topic of ovulation of induction, we observed unusual similarities in a number of randomised controlled trials (RCTs) published by two authors from the same institute in the same disease spectrum in a short period of time. We therefore undertook a focused analysis of the data integrity of all RCTs published by the two authors. We made pairwise comparisons to find identical or similar values in baseline characteristics and outcome tables between trials. We also assessed whether baseline characteristics were compatible with chance, using Monte Carlo simulations and Kolmogorov-Smirnov test. For 35 trials published between September 2006 and January 2016, we found a large number of similarities in both the baseline characteristics and outcomes of 26. Analysis of the baseline characteristics of the trials indicated that their distribution was unlikely to be the result of proper randomisation. The procedures demonstrated in this paper may help to assess data integrity in future attempts to verify the authenticity of published RCTs.