The missing data that cost $20bn

Marketing is what you do when your product is no good, said Edward Land, scientist and inventor of the Polaroid instant camera. The same notion filled Tom Jefferson’s head when he began to reappraise his initial conclusions about neuraminidase inhibitors and the risk of influenza complications and hospital admissions (doi:10.1136/bmj.g2227). Keiji Hayashi, a Japanese researcher, alerted him to the existence of unpublished trials, trials that were not included in his Cochrane review of 2006. From trusting the literature, researchers, and companies, Jefferson moved to a position of deep scepticism. Many trials were unpublished, data weren’t shared, and decisions on purchasing, stockpiling, and using the drugs were based on a slim and skewed representation of the total evidence base.

This week is the …