Two years after the pharmaceutical giant Roche promised the BMJ that it would release key trial data on oseltamivir (Tamiflu) for independent scrutiny, the safety and effectiveness of this anti-influenza drug remain uncertain, a new meta-analysis by the Cochrane collaboration says.

Cochrane researchers set out to test Roche’s claim that the drug prevented complications and reduced the number of people needing hospital treatment. Their report says that Roche’s refusal to provide full access to all its data leaves critical questions about how well the drug works unresolved (BMJ 2012;344:d7898, doi:10.1136/bmj.d7898).

Roche maintains that it provided the Cochrane researchers with enough information …