In mid-2021, a handful of meta-analyses looked at the use of ivermectin, a drug to treat people infected with parasitic worms, against COVID-19. The analyses included data suggesting it was effective, which came from clinical trials that almost certainly did not happen as described. (Problems detected in reported trials include copied data, results for patients who died before the trial began, and disputes about whether a trial occurred at all.)
A few weeks later, a meta-analysis by Cochrane, an international group that specializes in reviewing evidence in medicine and health, found that ivermectin had not been shown to be effective (M. Popp et al. Cochrane Database Syst. Rev.7, CD015017; 2021). That analysis took several steps to exclude fraudulent studies. But confusion and distrust continue.
In my view, most reported clinical trials are conducted properly, but fraudulent studies are still rife, and not confined to COVID-19. An analysis of trial manuscripts submitted to the journal Anaesthesia found that upwards of 40% probably contained false patient data (J. B. Carlisle Anaesthesia 76, 472–479; 2021).
