Editor, as a South Asia born (high risk) long-term resident of Scotland (high risk) I am at double jeopardy of coronary heart disease as recently confirmed by the Scottish Health and Ethnicity Linkage Study.1;2 My cardiologist colleagues (but not my GP) have advised me to start statins. So, I looked for numbers needed to treat (NNT) to guide my decision. I was, therefore, intrigued by Andrew Tresidder's call for the publication of NNTs in the BMJ correspondence column (BMJ 2014;348:g3458). I found NNTs in a recent review by Dr Enas Enas, a great enthusiast of the use of statins, especially in South Asian populations, including for people at low risk.3 The numbers published by Enas have helped me to make a difficult decision--after all, as a medical professor of public health who has been specialising in the prevention and control of cardiovascular disease and diabetes, especially in South Asian populations, I need to get it right for reputational as well as health reasons.
Enas bases his numbers on a 2013 Cochrane review. Enas reports that NNT equals 167 for low risk (less than 1%) and 67 for intermediate risk (1-2%) individuals. Enas reinterprets this as meaning 1000 low-risk people would need to be treated for five years to prevent six major adverse cardiovascular events. Enas notes the increased risk of type II diabetes from statin use and also estimates that 100 of the thousand people treated would have myopathy (that the same might occur with placebo is irrelevant as I will not be taking a placebo). Enas judged that the benefits of treatment in low risk subjects far outweigh any possible hazards and concluded that early and aggressive statin therapy offers the greatest potential for reducing the continuing epidemic of coronary artery disease among Indians.
The established cardiovascular risk factors I have are my Indian background, a sibling who had a heart attack in his mid-50s, and age (61).The Q risk calculator (http://www.qrisk.org/lifetime/index.php) indicates I have about 13% risk over the next 10 years, when ignoring the family history and 22% when including it. After reflection I decided against medicating myself with statins. Even with NNTs, medical qualifications, and advice from cardiologist friends I have found the decision difficult . I suspect that members of the general public will rely upon medical advice in making such a decision. The values and beliefs of the medical profession will, therefore, determine the direction of travel, even more so than the quantitative evidence.
(1) Bansal N, Fischbacher CM, Bhopal RS, Brown H, Steiner MF, Capewell S et al. Myocardial infarction incidence and survival by ethnic group: Scottish Health and Ethnicity Linkage retrospective cohort study. BMJ Open 2013 September 1;3(9).
(2) Bhopal RS, Bansal N, Fischbacher C, Brown H, Capewell S. Ethnic variations in chest pain and angina in men and women: Scottish Ethnicity and Health Linkage Study of 4.65 million people. European Journal of Preventive Cardiology 2012 December 1;19(6):1250-7.
(3) Enas EA, Kuruvila A, Khanna P, Pitchumoni CS, Mohan V. Benefits & risks of statin therapy for primary prevention of cardiovascular disease in Asian Indians – A population with the highest risk of premature coronary artery disease & diabetes. Indian J Med Res 2013;138:461-91.
Competing interests: No competing interests