A REANALYSIS of evidence supporting the anti-influenza drug oseltamivir has undermined confidence in published research for one of the review authors, who has called for an overhaul of the way systematic reviews are conducted.
Professor Chris Del Mar, professor of public health at Bond University, Queensland, was one of seven Cochrane researchers who reanalysed the evidence for oseltamivir (Tamiflu) using primary trial data, much of which was unpublished. (1)
They found several inconsistencies with published reports, such as that oseltamivir did not reduce hospitalisations. The reanalysis also showed a possible underreporting of adverse events, although the drug was found to reduce duration of influenza symptoms by 21 hours.
Governments globally had spent billions of dollars stockpiling oseltamivir after a previously published analysis, funded by Roche, found that the drug reduced complications and hospital admissions. However, eight out of the 10 trials used in the Roche analysis were unpublished and their data sets were not available from either the authors or Roche. (2)
The researchers postponed an analysis of zanamivir (Relenza) evidence because its manufacturer, GlaxoSmithKline offered to provide individual patient data.
The Cochrane researchers found that 60% of patient data from oseltamivir trials had never been published, a fact Professor Del Mar described as “disgraceful”.
The research has also raised questions about the mechanism of action of oseltamivir.
“One of our team has suggested that oseltamivir’s effect might not to be due to an antiviral action but to do with a general brain suppressant … if it is working that way, then it’s no better than paracetamol but a lot more expensive”, Professor Del Mar said.
http://www.mjainsight.com.au/view?post=confidence-in-research-shattered&post_id=7790&cat=news-and-research
