An investigation of 51 publications by a single author due to doubts about data integrity.

Abstract Background: We noticed two unusual three-arm randomised controlled trials (RCTs) from Menoufia University, a centre where several fabricated papers in Obstetrics and Gynaecology have recently been identified. We, therefore, evaluated the published studies by the lead author, Dr M. Rezk, for research integrity. Methods: We searched for RCTs and cohort studies authored by Dr Rezk, and compared recruitment periods, numbers and study submission dates. We read the publications carefully to identify any unusual features.Results: Dr Rezk authored 51 studies, 17 RCTs and 34 cohort studies. Two pairs of RCTs (four trials) showed extensive data copying of baseline and outcome data. Another set of four trials and two cohort studies each recruited identical patients from the same hospital over overlapping time periods. The reported recruitment rates in two of those RCTs were implausible, and there were frequent examples of identical baseline data between the same two RCTs and a third trial. In 15 of the trials, we were able to compare the number of participants allocated to each group. In two, the method of randomisation (shuffled cards) would result in exactly equal-sized groups. In eight of the other thirteen, exactly equal-sized groups were achieved, and in two further trials, differential loss to follow-up led to exactly equal-sized groups for analysis.Nineteen of 34 cohort studies were reported to be prospective or to include a prospective component, but 11 of these were received by the journal before the last participant could have been followed up. One cohort reported a biologically implausible rate of disease and another an implausible recruitment rate. Two cohorts of women with hypertension in pregnancy reported identical summary statistics on multiple occasions in the tables displaying baseline characteristics. Two other cohorts of women with rheumatic heart disease in pregnancy, with identical recruitment criteria and overlapping recruitment periods, reported implausible differences in baseline BMI and neonatal mortality. Finally the probability of observing the excess of even numbered categorical variables reported in Dr Rezk’s papers overall is infinitesimal.Conclusions: Our assessment of the work of Dr Rezk shows prima facie evidence of data fabrication. We call for an investigation of these studies, including assessment and re-analysis of the original data. Until then, the studies of Dr Rezk should neither directly nor through meta-analysis be used to inform clinical practice.