Should everyone over 40 really take a statin?

"Everyone over 40 years old should take a statin - men and women." Those are not my words but those of Professor Sir Magdi Yacoub who is one of the world's most eminent heart surgeons. Interviewed on the Today program this morning he, with typical surgical aplomb, stated his opinion. When asked if every man over 50 should be on a statin he replied. "Definitely, I would say every man over 40" and what about for women Justin Webb asked, "Yes women too." So that's clear according to the Professor everyone over 40 should have a statin and not to do this he said was lunacy. 

We are in a statin war, being played out on the media battlefield. Each side lobbing studies and statistics at each other across the 7 million people who take these drugs every day and the millions more who some think ought to. People are confused by these disagreements between the doctors as the two sides rage against each other. Into this toxic mix there is distrust of pharmaceutical companies, conflicts of interest and self-promotion amongst researchers and the wider social issues about the medicalization of the population.

Today was an minor assault by the Statinistas. Deploying a "big gun" in the form of Sir Magdi to state the case for statins. A generous dose of eminence-based medicine was administered aurally. Yacoub said that if the cholesterol is low then this would result in not only reduced rates of heart attack and strokes but also reduction in dementia and cancer. He said "If the cholesterol is extremely low then people look very young at an old age and lead a long and happy life, so not to take statins is a disaster." Linking observations made in people with a very rare genetic cause of extremely low cholesterol (PCSK-9 deficiency) to the effects you would expect from taking statins seems somewhat absurd and stretches the evidence on statins into new orbits. Even the most ardent trialists would be likely to agree that currently body of statin data does not support Yacoub's views. But rather than speculation about the a cure for cancer or dementia the most provocative statement he made was that everyone over 40 should be on a statin.

This is a debate about risk versus benefit. A debate about populations versus individuals. There is the strongest evidence that statins reduce the risk of heart attack and stroke. That cannot be denied. The reduction in risk is about 30%. The benefit is not dependent on the baseline level of cholesterol. If your risk is high you get a lot of benefit, if your risk is low, you benefit, but not so much.

A simple way to express this is the "Number Needed to Treat" or NNT. If the NNT is large then the treatment is not very effective in that group of patients and may approach the Number Needed to Harm. In other words if you treat a large group of people at low risk then you may help a few and harm a few. The problem here is deciding at what level of risk to offer treatment. For statins in primary prevention the NNT is 60 for heart attack and 260 for stroke. In people with established heart disease the NNT is 39 to prevent a heart attack, 125 to prevent a stroke and 83 to save a life. To the individual patient these seem like high numbers but when you consider that millions of people are on statins then they rapidly multiply making the reduction in heart attacks, stroke and death look impressive.

But we also need to keep in mind that giving statins for prevention where the risk is low is totally different from using them in high risk people. If we expose a large number of people to a small risk from the statin treatment then this is likely to yield more problems than if we were to expose a small number to a much bigger risk.

The classical argument about treating populations was put forward by Geoffrey Rose in his book and articles on the Strategy of Preventative Medicine. Rose argues that a mass approach is the only ultimate answer to the problems of a mass disease. But, however much it offers to the population as a whole, it benefits each participating individual very little. Take the example of diphtheria immunisation. 600 children need to be immunised in order that one life would be saved. In other words 599 wasted immunisations were given. The same case may be made over seat belts where the number of times a seat belt needs to be worn to prevent one fatality is about 25,000. This is the prevention paradox. The effectiveness you have to accept in mass medicine where the measure applied to many will actually benefit few. A measure that brings large benefits to the community offers little to each participating individual.  As Rose says: "We should not expect too much from health education as people won't be motivated to take the advice because there is little in it for them  especially in the short term."

So should you take a statin if your over 40 years old. Well it depends on your risk of cardiovascular disease compared to the average 40 year old. If you are at low risk because you don't smoke, your cholesterol and blood pressure are normal and you are otherwise healthy your benefit is very small. You may wish to take a statin and in that case either your doctor will prescribe it or you can buy 10mg simvastatin over the counter - it's your choice. If you are at increased risk compared to the average 40 year old because of raised blood pressure or elevated cholesterol then your benefit is higher and you are likely to be advised by your doctor to take a statin. Again it's your choice but the choice needs to be made after a proper discussion and the advice individualised and explained by someone with expertise in guiding the patient thought the arguments. Simply telling everyone over 40 to take statins is in the words of the Professor lunacy.

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