Tuesday, January 07, 2014

Dr David Tovey writes

Most people assume that when they visit their doctor they will receive impartial and expert advice based on the best current research. This expectation forms the basis for much of the trust invested in doctors and other health professionals.

In practice, the medical literature expands at a speed such that even the most committed clinician could not expect to keep abreast of it all. Many doctors read a sample of the highest profile journals in their speciality, but even this is insufficient. Research published in such journals usually represents a small sample of that conducted, and is skewed towards those studies that showed the treatment in question in a favourable light.

To overcome these problems, the past 30 years has seen the growth of a different form of research article: one that looks to summarise all the high quality research, not just the small proportion that has made it into The Lancet or BMJ. These articles are known as "systematic reviews" and the largest international producer of these is a network of researchers started 20 years ago in Oxford but now spread across 120 countries and including over 30,000 individuals. The organisation is called Cochrane, after a British researcher of the same name, and Cochrane Reviews are widely seen as representing the highest quality evidence on which health care decisions can be based.

The problem is that only about half the studies completed are published in journals at all. Despite the fact that this problem has been recognised for decades it has not been effectively tackled despite many attempts to do so. This failure has meant that health professionals and the public frequently have overly optimistic impressions of how effective treatments are. This is not simply an academic issue - it means that people have died or become ill as a consequence of misplaced advice from their health professionals.

The problem was highlighted recently by the publication of Ben Goldacre's book, "Bad Pharma". This was followed up by the setting up of the AllTrials campaign by Goldacre, Sense about Science, the BMJ, Cochrane and many others. The campaign calls for public and full disclosure of the methods and results of all research involving patients, on all treatments in current usage - a fairly modest and reasonable request you might think.

Everyone has heard of Tamiflu, a treatment developed by an iconic drug company, Hoffman-La Roche, to prevent and treat "flu". The reason for the drug's fame is that in the 2000s, many governments responded to a recommendation from the World Health Organisation (WHO) to stockpile the treatment, for use in a potential influenza pandemic.

The Public Accounts Committee has assessed the cost of stockpiling the treatment in the UK alone as being £424million. The WHO recommendation was based on the publication of a paper that summarised 10 trials and appeared to show that Tamiflu prevented severe complications of influenza. To be fair, the Cochrane Review team looking at this question was among those persuaded (albeit briefly) by this evidence, until a Japanese researcher pointed out that only a fraction of the research had been published. It proved to be a milestone.

The Cochrane team, led by Dr Tom Jefferson, realised that the feedback was crucial and set out to piece together a full picture of the studies conducted irrespective of whether the studies had been published in medical journals or not. They also approached the investigators of the studies that had been published and established that none of these had access to the trial data -which was held by Hoffman-La Roche. The Cochrane team therefore asked repeatedly for the full information and were refused despite a number of private and public assurances to the contrary.

The researchers decided to pull together a comprehensive analysis of all the studies and data submitted to regulatory organisations such as the US Food and Drug Administration (FDA), European Medicines Agency (EMA) and in the UK the Medicine and Healthcare products Regulatory Agency (MHRA) and National Institute for Health and Care Excellence (NICE). The team realised that the extent of the missing data was far greater than could have been imagined - indeed the unpublished studies represented a large majority of the research completed, including the largest single trial of Tamiflu. Also, there were inconsistencies between the "Clinical Study Reports" (CSRs) submitted to the regulators and the published study reports.

They therefore decided to produce a systematic review of data held in the CSRs, and to ignore published study reports - the first (and still only) time this had been undertaken within Cochrane. This is also a major undertaking given that they estimate that there are over 150,000 pages of data involved. The first version of this review was published in February 2012. This review noted that despite the assurances, Roche had still not provided access to all relevant data, and concluded that there remained uncertainty as to whether Tamiflu was effective in reducing the complications of influenza.

It is therefore not surprising that the Public Accounts Committee (PAC) has registered its concerns and its strong recommendation that all data from clinical trials should be made public. The conclusion that millions of people have been exposed to a treatment, at enormous cost to the public purse, despite the fact that independent researchers have been unable to verify it as being effective or safe, should trouble us all. That despite all the billions of public money spent worldwide on health research we are in this position of ignorance of the effects of most of the treatments taken every day is a true scandal of our times.

The Public Accounts Committee report is a major endorsement of the Alltrials campaign. The Committee's recommendations, if followed through, will lead to better understanding, by health professionals and the public, of the effects of medical treatments - and to more rational and safe healthcare decisions.

And what of the Cochrane Review on Tamiflu? In recent months both Roche and another drug company, Glaxo Smith Kline (GSK) have provided access to the full clinical trial data on two anti-influenza drugs, including Tamiflu, although with some information partially redacted. The research team, which receives financial support from the UK National Institute for Health Research, is expecting to complete its analysis in early 2014 and then, perhaps, we will know whether the billions invested globally in Tamiflu was worth the cost.

Dr David Tovey is the editor-in-chief of The Cochrane Library


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