A team of scientist–sleuths has flagged data-integrity concerns in 130 studies authored by the same biomedical researcher, a specialist in women’s health and gynaecology, and his colleagues. The sleuths published their findings in a peer-reviewed paper earlier this year.
Some of the studies that were identified as potentially problematic have been cited by other researchers or included in analyses that could inform clinical practice. The number of papers being questioned is among the highest by a still-active life-scientist, say some specialists.
The 130 studies were published between 2014 and 2023 and report the results of clinical trials and other research on maternal and women’s health. The highlighted problems include oddities in reported statistics, unfeasible results and text that is identical to other papers. Ahmed Abbas, an obstetrician and gynaecologist at Assiut University in Egypt, is listed as a co-author or corresponding author for all 130 articles. Abbas did not respond to Nature’s request for comment.
Some of the papers remain part of the literature. Eleven have been retracted. Before it was retracted, one of those 11 was included in a 2019 meta-analysis on a treatment to prevent miscarriage. The retractions of the paper by Abbas and his team and another, unrelated paper will probably change the conclusion of the analysis, says one of the 2019 work’s authors.
The inclusion of a potentially unreliable study in a systematic review can have harmful consequences, because “it can immediately affect how a surgeon or an [obstetrician–gynaecologist] is doing their job”, says James Heathers, a forensic meta-scientist at Linnaeus University in Växjö, Sweden, who was not involved with the investigation that identified the data-integrity concerns.
Women’s health specialists are actively developing strategies to prevent the publication of questionable data. But they say that once these papers are published, it’s difficult to purge them from the literature.
Alaa Mohamed Ahmed Attia, the dean of the Faculty of Medicine at Assiut University, with which Abbas is affiliated, did not respond to Nature’s request for a comment on the concerns raised about Abbas’s publications in this year’s peer-reviewed paper.
The 130 flagged studies were described in a paper published in May1 in the Journal of Gynecology Obstetrics and Human Reproduction by obstetrician and gynaecologist Ben Mol, at Monash University in Clayton, Australia, and his colleagues.
In 2016, Mol peer-reviewed an unpublished manuscript co-authored by Abbas about a clinical trial of the hormone progesterone to prevent miscarriage. Mol noticed discrepancies in the paper and notified the journal, he says. The journal rejected the work by Abbas and his team. But in 2017, a different journal, The Journal of Maternal-Fetal & Neonatal Medicine, published a version2 of the manuscript that included changes to the sections that Mol had flagged, he says. The journal ultimately retracted the paper in December 2019.
According to the retraction notice, the journal’s editors-in-chief learnt that previous versions of the manuscript “showed significant changes to the underlying data”. The notice also said that when contacted, the authors could not provide the original data to verify the results. According to the journal's publisher, Taylor & Francis, concerns about the paper were first raised in February 2019. The resulting investigation led to the article’s retraction later that year, the publisher says. Abbas did not respond to Nature’s request for comment about the retraction.
Mol’s team decided to survey all papers by Abbas with the exception of literature reviews, case reports and studies done as a part of an international collaboration. They identified 263 papers that included Abbas as an author. These studies collectively enrolled more than 74,000 participants between 2009 and 2022.
Of the 263 studies analysed in the paper, 130 — almost half — raised the sleuths’ concerns. Some of the papers had statistics that seemed unfeasible. One used wording that was similar to that of a previously published paper. The articles that the team flagged appeared in journals produced by several publishers such as Taylor & Francis and Springer Nature, which also publishes Nature. Nature’s news team is editorially independent of its publisher. When asked for comment by the news team, Springer Nature did not respond.
The sheer number of studies that were claimed to have been produced in such a short period of time caught the attention of Mol’s team. According to the reported registration and publication timeline of the papers, in May 2017, Abbas would have been conducting 88 simultaneous clinical studies. Catherine Cluver, a gynaecologist and obstetrician who leads the preeclampsia research unit at Stellenbosch University in South Africa, agrees with Mol’s team that it seems unfeasible to conduct such a large number of studies at one time. “Doing all of the regulatory work, the ethics approvals, making sure the trials are being run correctly … I think there is no way you could do more than four or five, and even then, it’s a push,” she says.
A common issue identified by Mol and his colleagues was statistical oddities. One paper they flagged, published in the journal Proceedings in Obstetrics and Gynecology3, evaluated the effect of the medication esomeprazole in women with the pregnancy complication preeclampsia. The sleuths noted that the last digit of 31 of the 32 values in tables 2 and 3, including means and standard deviations, are even numbers (see ‘Even numbers abound’). In scientific data, the digits of such measurements and statistical results tend to be more equally distributed between odd and even numbers, so the chance of having so many values ending in even numbers would be low. The numbers are a “concern”, according to the paper by Mol and his team.
