There has been a flurry of media reports over new research from Harvard University suggesting that “almost all” men over 60 and women over 75 should be taking statins to reduce their risk of stroke and heart attack.
The research explores the likelihood of people having a cardiovascular event across age ranges and aims to estimate the number of adults in England who will need to used statins under guidelines issued by the National Institute for Health and Care Excellence (NICE).
Behind the numbers – calculating risk
Analysing the numbers behind the research, the OU’s Emeritus Professor of Applied Statistics, Professor Kevin McConway, said:
Just because the algorithm for calculating the risk of a cardiovascular event over the next 10 years puts that risk at over 10% for almost all males aged 60-74, and for a majority of women in that age group too, that doesn’t mean that it’s incorrectly calibrated.
I’ll be personal here. I’m 66, and according to the official life tables put out by Britain’s Office for National Statistics, the risk of death in the next 10 years for an average man of my age is about 18%. None of us lives forever, and, despite all the medical advances and increases in life expectancy, well, I am still getting on a bit. More than one in four of deaths of men in my age group in the UK are from cardiovascular disease. The risk calculated by the algorithm is of all cardiovascular events, not just those that lead to a death. So I’m well aware that the risk of a cardiovascular event in the next 10 years for an average man of my age is over 10%. That’s about averages, but (for example) the charts published by Heart UK which relate the risk to age, smoking, blood pressure and cholesterol levels, and use a different risk algorithm, also put the 10 year risk at over 10% for all men aged 60 and over, and for most women.
Making sense of health advice
NICE’s 2014 guidelines recommend that anyone with a one-in-10 or higher chance of developing cardiovascular disease should be taking statins. Based on this, and Harvard’s calculations of the number of people at risk, the research concludes that 11.8 million (37%) adults in England aged 30–84 years, including almost all males >60 years in all females >75 years, require statin therapy.
Assessing this, Professor McConway says:
Actually the key question here for me is not about the risk algorithm, but about whether the NICE advice makes sense. If someone’s 10 year risk of a cardiovascular event is over 10%, but not by much, below the old guideline of 20%, is the balance between the health gains from the statins and the risk of possible adverse effects, taking into account the cost of the drugs, in favour of them taking the statins? NICE thinks it is, though it does very clearly recommend that statins should be offered only after a full discussion between the patient and their doctor, taking into account personal circumstances, other ways that cardiovascular risk might be reduced, and the risks and benefits involved. Personally I agree with NICE on this (and I do take statins daily myself, for what that’s worth – my personal circumstances are my own and others will differ), though I do acknowledge that there remains some controversy about these recommendations. The authors of this paper are right to point out that there are resource implications for GPs (and others), but it’s no secret that there are costs associated with keeping us older people healthy.
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