TY - JOUR T1 - Examining uncertainty in the primary prevention of cardiovascular disease JF - Open Heart JO - Open Heart DO - 10.1136/openhrt-2016-000401 VL - 3 IS - 1 SP - e000401 AU - Rahul Bahl Y1 - 2016/03/01 UR - http://openheart.bmj.com/content/3/1/e000401.abstract N2 - Making decisions in areas of uncertainty is one of the more challenging aspects of free will in general and medicine in particular. This is especially the case when those decisions relate to matters of life and death. Finegold et al1 present a paper in Open Heart that may considerably complicate a scenario usually thought of as relatively straightforward, namely, the decision to start primary prevention therapy with statins to reduce the risk of death from cardiovascular disease (CVD).At the heart of the study is a computer model generated from national mortality statistics and a validated cardiovascular risk score. A hypothetical population is generated with known probabilities of cardiovascular and non-cardiovascular death (eg, 1000 50-year-old male non-smokers with normal cholesterol and blood pressure). These probabilities are used to calculate the lifespans of the imagined individuals in this population. The risk of cardiovascular death is then reduced (simulating the effect of statin therapy) and the model run again to see what the effect is on the lifespan of each person. The important thing to realise is that with these models it is possible to examine and re-examine the lifespans of the same set of individuals over and over while altering the variables and observing the effects. Clearly, such experiments are not possible using actual human beings.There are a number of key findings. First, in any group of individuals with a given risk of CVD, only a few gain any lifespan from reducing their CVD risk, with the vast majority seeing no increase at all. Second, in a group with a higher level of CVD risk, there are greater proportions of people who benefit, with those who do benefit tending to gain a similar amount of lifespan regardless of CVD risk level. Finally, it shows that starting therapy earlier in … ER -