The BMJ's Expression of Concern: A Stem Cell Study's Troubling Data
The BMJ has issued an expression of concern regarding a paper claiming stem cell therapy can reduce the risk of heart failure. This move comes after sleuths and scientists identified a 'complete mismatch' between the study data and the article itself.
As reported last week, the October 29 paper included results of a phase III clinical trial in Shiraz, Iran. Critics quickly pointed out discrepancies in the data on PubPeer, including psychologist Nick Brown, who noted a 'curious repeating pattern of records in the dataset' every 101 records.
The BMJ's expression of concern, published today, acknowledges issues with the data, including irregularities, discrepancies in age criteria, and undeclared conflicts of interest. Dorothy Bishop, a professor of developmental neuropsychology at Oxford University, was the first to highlight issues with the paper, specifically the claim that the study enrolled only patients under 65 years of age. However, in the accompanying data, 127 patients were older than 65, a 'complete mismatch'.
On PubPeer, Bishop also pointed out potential conflicts of interest, noting that author Anthony Mathur, a researcher at Queen Mary University of London, is a shareholder and trustee of the Heart Cells Foundation, a charity funding a unit for administering stem cell therapies to cardiac patients.
The BMJ's notice states that the editors judge the trial may have breached accepted practices, and the results may not be reliable. The journal plans to investigate fully and consider an 'auditable replacement dataset' provided by the authors. Most of the authors, including corresponding author Armin Attar, are researchers at Shiraz University of Medical Sciences.
After the article's publication, sleuths continued to identify issues with the paper. Gideon Meyerowitz-Katz, a research fellow at the University of Wollongong in Australia, noted 'oddities' in the data, including that nearly half of recorded heart rates were divisible by five. He also pointed out an 'unexpected' pattern in patient temperatures, with 42 out of 311 recorded temperatures being exactly 36.2 degrees Celsius.
Retractions in The BMJ are rare. The journal issued its first retraction in 1989 and has retracted a total of just 12 articles, according to the Retraction Watch Database.
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