This study by the Cochrane authors is the result of a four-and-a-half-year struggle to access and use trial data, which was previously unpublished and even hidden from view.
It highlights with certainty that future decisions to purchase and use drugs, particularly when on a mass scale, must be based on a complete picture of the evidence, both published and unpublished.
We need the full data from clinical trials made available for all drugs in current use. The new European Clinical Trials Directive will bring greater openness of data on future drugs. But 85 per cent of the drugs in current use are based on data that is more than 10 years old. The Tamiflu saga highlights the enormous challenge we face if we are to have a system that patients and the public can trust.
We need everyone involved in the process of manufacturing, evaluating and regulating drugs to make all data available, even if it means going back 20 years. Otherwise we risk wasting precious resources and harming patients.
Through their exhaustive scrutiny of the data contained in clinical study reports – the lengthy documents held by the drug's manufacturer Roche and previously seen only in part by drug regulators – the Cochrane authors have set exacting new standards for systematic reviewers and decision makers. Their fight for the data has also shown, in more detail than ever, how deeply flawed is the entire system of drug evaluation and regulation.
The complete evidence from the clinical study reports paints a much less positive picture of Tamiflu than was presented to regulators, policy makers, clinicians, and the public. Important benefits have been over-estimated and harms under-reported.
In particular the Cochrane review found no compelling evidence to support claims that Tamiflu reduces the risk of complications of influenza such as pneumonia and hospitalisation, claims that were used to justify international stockpiling of the drug
The review's conclusion should lead to serious soul searching among policy makers. Why did no one else demand this level of scrutiny before spending such huge sums of money on one drug? And why do we have a system of drug evaluation and regulation that is incapable of providing patients, clinicians and policy makers with timely, reliable, independent information?
Indeed the current system seems to be designed with the opposite end in mind.
Dr Fiona Godlee, is the editor-in-chief of the British Medical Journal