Posted by: beyondtheheadlines26 November 2013
The health of America is in trouble. Life expectancy is noticeably lower than in other developed nations, 15% of the country lives precariously without health insurance, and the launch of Obamacare was so badly botched that this much needed health reform is in serious jeopardy. Not to worry, though, the American Heart Association and the American College of Cardiology have a plan that will rescue the health of the nation: put a third of US citizens on statins - that ought to do it!
The new guidelines, released this month was widely reported in the UK press. The Mail misleadingly called the publication a new study rather than a set of guidelines, while the BBC gave a more measured view, including a revealing statistic that roughly half the expert panel had financial ties to the makers of cardiovascular drugs.
The major change to the guidelines is that there is less emphasis on absolute levels of cholesterol, and a new category for treatment in those aged 40-75 with an estimated 10 year cardiovascular risk of 7.5%. Current UK guidelines recommend treatment at 20% risk, but NICE say they are looking at the same evidence as the US, before publishing new guidance next year. Despite the important debate in the medical press about overmedicalisation - spearheaded by the BMJ’s excellent Too Much Medicine series - we can expect a lowering of treatment thresholds when NICE issues its verdict.
The problem with the way we present guidelines, though, is that they are far too black and white, when the world of medicine we inhabit with our patients is generally full of grey. The question we should be asking is not what the threshold should be for treatment, but how to empower patients to make their own, informed decisions - because ultimately, the level of risk a patient is prepared to accept before they take a tablet is a personal decision, and a panel of experts has no authority to tell patients what risk they should, or should not take.
If we use the 7.5% cut-off, for instance, and assume that taking a statin for 10 years would lead to a 50% reduction in significant cardiovascular events (which is likely to be a gross over-estimate). This means that 3.75% of patients would avoid an event by taking the drug - call it 4% for ease of maths - and 96% would not benefit. The number needed to treat (NNT) is therefore 25 to avoid one event. What will our patients think about this? Surely that is entirely subjective and not for experts to dictate? One patient may have seen a close family member affected by a devastating stroke and might think any ability to reduce the risk of stroke is an opportunity to be grasped, another might consider the 3,650 tablets they would have to swallow over 10 years and wonder if a 1 in 25 risk is really worth trying to avoid. In reality, the benefits of statins are much smaller than a 50% reduction, and so the NNT for low risk patients is likely to be 50, 100 or even higher.
We need a different approach to guidelines, one based on NNT, and the corresponding number needed to harm (NNH) (like this excellent calculator from ClinRisk Ltd.) There should be a lower level below which the NHS says treatment is not justified on the grounds of either harm or rationing, and then a range of NNT and NNH based on individual risk. Expert panels should analyse the evidence to provide these figures, not to tell people what to do, and doctors and their patients can be given the freedom and flexibility of a large area of grey, in which they can personalise treatment and truly empower patient choice. The experts and policy-makers won’t like it though - because it involves trusting patients, and we’ve never quite mastered how to do that.
Dr Martin Brunet is a GP in Guildford and programme director of the Guildford GPVTS. You can tweet him @DocMartin68