A panel of enthusiasts, sceptics and methodologists chaired by Prof Carl Heneghan.
Monday April 13th 12:30
Each panel member was asked – Statins in people at low risk of heart disease: How good is the evidence base and how do we fix it? Their responses (given below) will be justified in a five minute talk before opening to the floor for debate.
Prof Klim McPherson – Many randomised trials comparing statins with placebo demonstrate a proportional reduction in CVD risk, of around 20%. This benefit seems reasonably robust across the risk range. It follows therefore that for low risk people the absolute benefit of statins is small, approximately reducing a 10% risk in ten years to 8%, which is barely a strong determinant of choice. What we know from pooling these trials is that in spite of this this affect, mortality rates are not convincingly reduced in the statin groups. The question then is what are the disadvantages of taking a pill every day for 10 plus years, which is problematic of itself. Evidence comes from anecdotal experience that statins are associated with muscle problems, pain and stiffness. Stopping them and symptoms tend to vanish, but sometime changing the statin does away with them. Liver dysfunction is another possible side effect. But these are anecdotal because such things were apparently not measured properly in the trials, sadly. Also randomised trials show a clear increase in diabetes (~9%) among statin users.
We need to get to the bottom of these matters, by exploring the individual patient data and the trial protocols, before making recommendations.
Prof Rod Jackson – I agree with Klim McPherson that the RCT evidence demonstrating proportional reductions in risk of CVD from statins is robust and I find the evidence that this proportional reduction is similar for patients across a wide range of pre-treatment CVD risks quite compelling. I also support the conclusions of the expert committees behind recent UK and US guidelines that the benefits of statins outweigh the harms in patients with a pre-treatment 10-year CVD risk above about 10% (or 7.5% hard CVD in the US).
However I don’t support the inference in both guidelines that this level of CVD risk is an appropriate treatment threshold rather than the beginning of a conversation about the likely magnitude of treatment benefits. The biggest gaps in our evidence base are not about the proportional benefits and harms of statins, but about how to predict pre-treatment risk more accurately and how to better communicate predicted benefits and harms of treatment. The great statin debate should be about the evidence and the tools we need to communicate with patients and their similarly ill-informed doctors so they can make more informed decisions before embarking on lifelong daily medication.
Iona Heath – The academic community needs access to the individual patient data that underpins the current recommendations. It is unacceptable for NICE to change their guidance on the basis of data that it not available for scrutiny.
There is a gross mismatch between the rate of side effects reported in daily clinical practice and that reported in the major trials. We need to understand much more clearly how harms are sought out and defined within these trials.
We need to understand more about the willingness of well people to take daily medication in order to reduce an already small risk. What is the range of willingness and what is the threshold of absolute risk reduction that is expected?
Finally, all guidance issued by NICE should take into account the opportunity costs within primary care. The most recent guidance failed to acknowledge the huge amount of time which is to be taken up by offering shared decision making consultations to everyone now above the revised threshold. Time given to the well is time taken away from the already sick.
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