Daily Mail Online: Why randomised controlled trials don’t tell you what you want to know

April 28, 2013 by Jerome Burne

Earlier this week the Daily Mail published my feature on side-effects and how patients aren’t properly warned about them. Antidepressants, for instance, can cause compulsive heavy drinking but you wouldn’t know it from the drug information leaflet.

The article is about campaigning psychiatrist Dr David Healy, who believes patients need a more truthful account of the side effects they risk. It describes his new website – Rxisk.org – that makes it easier to report side-effects and provides a forum where you can swap experiences with other pill users.

Information about side effects is often poor because it gets hidden by the companies running the trials. A campaign by doctors and journals is now well under way to force drug companies to be more transparent.

Turning garbage into gold

But that’s not enough, according to Healy. He believes there are serious problems with the randomised controlled trial (RCT), the so-called gold standard of evidence based medicine, used to test treatments and decide which ones should be licenced.

Rather than distinguishing safe and effective medical treatments from ones that are dangerous and/or useless, the results from RCTs are frequently misleading and wrong. The RCT, he says, is a processor for turning garbage data into drug company gold.

At first sight his critique appears ridiculous. It is a full-frontal challenge to the whole idea of evidence based medicine. You have to have a way of telling if a drug works and is safe and the RCT has been used for years – since the 1960’s in fact – when it was introduced as a response to the thalidomide disaster.

It works by dividing patients randomly into two groups; one lot gets the drug, the other an inert placebo pill. A few months later the results reveal which group benefited more. Two positive RCTs are needed to get a licence to market a drug.

A serious barrier to treating chronic disease

Healy’s case against RCT’s is not based on bare-faced fiddling of results by the drugs companies, although he’s often exposed it. Even if all trials were squeaky clean they would still be a serious barrier to developing really effective ways of tackling the various lifestyle diseases that are threatening to cripple Western health services.

Take the rule that you only need two RCT’s to get a licence. What about if you also have three negative ones where the drug came out as no better than a placebo? At the moment they simply don’t count. This has everything to do with bureaucratic rules and nothing with scientific rigour. Its an arbitrary rule that deprives doctors and patients of valuable information about what the drug does or, just as importantly, doesn’t do.

But there is more fundamental problem. Properly conducted RCTs are supposed to tell you if a drug is effective. But what does “effective” mean? The poster boy…

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