How a Cochrane review update turned controversial

Systematic reviews are designed to synthesise the most reliable evidence on the effects of interventions. Following the outbreak of influenza A/H1N1 in April 2009, the UK NHS National Institute of Health Research commissioned an update of the Cochrane systematic review of neuraminidase inhibitors in healthy adults. In retrospect, our review began on a naive note. Although the review had last been updated in 2008, our new task was to include a safety assessment component. Tom Jefferson, who led the review, wrote to the group then just being formed, “Dear Friends…although it is always dangerous to pre-judge the issue, I expect no new effectiveness data but a lot of pharmacovigilance data.” Two days later, a paediatrician from Japan, Keiji Hayashi, submitted a comment to the Cochrane Collaboration that would ultimately leave us doubtful about the ability of systematic reviews to deal with the challenges of contemporary pharmaceutical evaluation1 (see …