Doctoring Data: How to sort out medical advice from medical nonsense
Pub: August 2015
‘Cholesterol lowering may change what is written on your death certificate, but it won’t change the date.’
I decided to take time out from Booker reading to read the latest book from Macclesfield GP, Malcom Kendrick. His last book was entitled ‘The Great Cholesterol Con’, where he took aim at the perceived medical wisdom that lowering your cholesterol was good for you.
In this latest book he aims wider and tries to:
- alert readers to look beyond the headline and surface of any medical claim to find the evidence behind the claim
- association does not mean causation: Just because something is associated with a condition/diseases is not the same as saying it causes or automatically results in that condition/disease.
- recognise the difference between relative and absolute risk in claims: “If the absolute risk is hidden away, then you can confidently assume that it is so vanishingly small that the authors chose not to highlight it, as it would significantly weaken their message.”
- beware of the words: words ‘lives saved’, or any version thereof: “You cannot save a life, all you can do is delay death.’ You will also know that anyone who combines the words ‘saved’ and ‘life’, or any version thereof, with regard to a clinical trial, is no longer a scientist. They have effectively – if unconsciously – become a drug salesperson. However academic they may claim to be.”
- look for the mortality effect: does treatment ‘cure’ a supposed symptom but shorten your life? If it does not state the mortality effect it is because it was negative.
This is a highly entertaining read, with views on cancer screening, high blood pressure, type 2 diabetes, obesity, mastectomies, and high cholesterol and more – and how the expert opinion and guidelines on all of these have been formed, fascinating. Even covering my favourite – the old fashioned method of moving the goal posts:
“Narrowing the boundaries of ‘normal’ is a technique used in many different areas of medicine. When I graduated in medicine, a high cholesterol was 7.5 mmol/L. Then it became 6.5, then 5.5, now it is 5. Or 4, if you have had a heart attack or stroke. In the latest US guidelines ‘optimal’ cholesterol level for healthy people is 4.4 mmol/L (In US units this is 170 mg/dl). By driving the definition of high cholesterol ever downwards, we have reached the point where more than 85% of people now have a ‘high’ cholesterol level, which needs to be lowered. This is fine so long as you do not question the inherent nonsense that the vast majority of the population can possibly have a dangerously high level of something. Ever come across the concept of ‘average’ guys?”
The most interesting claim/fact in the book? “in no statin study done has there been an impact on overall mortality in women. None, ever.”
I apologise for picking out Cholesterol based data but as one of those with ‘high’ cholesterol, and not having read his previous book, these were of particular interest to me. But a lot of the hard evidence for claims made in relation to some of the other highly diagnosed and prescribed medicine areas are also demonstrated to be equally flimsy, or at least enough that you should do your own research and digging before being blindly corralled into taking a handful of pills for the rest of your life.