Thursday, 3 March 2011

Delivering the evidence-based medicine message

This is a slightly off-topic post for this blog. I say slightly off-topic because it does not specifically relate to autism spectrum conditions, although the general theme of the posting may hold some relevance.

I blogged recently on the welcome involvement of the National Institute for Health & Clinical Excellence (NICE) in the development of National guidelines relating to various aspects of autism. In case you don't know, NICE are the agency in the UK who deliver guidance on all things relating to health and disease. NICE accomplish this via the development of guidelines based on the best- and most current available evidence.

The reason why NICE are relevant to this post, is the connection with evidence-based medicine (EBM). EBM works on the premise that science delivers recommendations. It's as simple as that. What the results of properly-conducted, properly-controlled, properly-reported studies tell us, should guide our actions, whether preventative or restorative, in relation to health and ill-health.

OK, we all know that we are not the same. Our risks of ill-health, disease (and death) vary wildly as a function of our genes and our environment. Hence EBM works on the idea that we are 'mostly' the same and that one or more recommendations will work for 'most' of us (via the normal distribution) - the common good - if you are unlucky enough to be one of the ones at the periphery where EBM does not work..erm, pass.

Recently, I have come across a few examples where EBM has perhaps slipped up. I say slipped up but EBM is not really to blame, rather our interpretation of EBM. An article appeared in one of the January 2011 issues of The Pharmaceutical Journal (vol.286, pp.19-20) by Rod Tucker (a community Pharmacist). In the article, Tucker deconstructs some of the 'myths' about what keeps us healthy. It is an interesting read. He discusses various research on the 5-a-day slogan, the role of fat in health, exercise in weight control and alcohol consumption and health. His conclusions: 5-a-day is 'unlikely to protect us against cancer or chronic diseases' (8-a-day might have some impact on risk of heart disease), there is little convincing evidence that saturated fat is 'particularly harmful', working up a sweat in the gym 'will not shed that spare tyre' and the safe limits for alcohol are 'somewhat arbitrary'. Remember this is a practicing Pharmacist saying all this, not me. The issue of fat in our diet has also been covered by other bloggers and may be relevant to autism (we wait and see).

The second example comes from a very recent posting suggesting that there is a greater risk of death in people with type 2 diabetes from lower salt consumption. You read it right: lower salt consumption is associated with a greater risk of death in this group (no, it is not an early April fool). This is written by a physician, not me.

At this point I will stress that I am not advocating any of these readings of the evidence; rather just reporting them (please do not start tucking into that block of beef dripping whilst glugging down that bottle of gin whilst sat reading this blog for hours on end). Here however we have two reports which cover a number of lines of good evidence that are contrary to current thinking and guidelines. Guidelines which are supposed to be governed by EBM but rather might seem at odds with what the current science is saying.

One could forgive the fact that science is based on probability not absolutes and that there are perhaps other issues involved in the EBM decision-making process. For example, fruit is a good source of dietary fibre and fibre is good for bowel health (keeping you regular). Safe limits on alcohol are there also to demonstrate the long term effects of sustained use on organs like the liver; also the societal effects following over-use (Friday and Saturday nights in most Casualty departments in the UK are a good example).

There are no easy answers as to why we have taken the EBM decisions that we have - sometimes seemingly at odds with what the evidence states. One could argue that indecisiveness and changing of opinions perhaps erodes the authority and the message being put forward. Readers in the UK might remember the BSE story and that child, that burger and that Minister. Can you imagine if the Department of Health came out and said that 5-a-day is not really all it's cracked up to be?

On the other hand maybe this has got more to do with how the message is put across. Telling people that A causes B and that C will effect D in such a 'universal' fashion whilst simplifying things also makes it very difficult to say 'hands up, we were wrong'. Perhaps the way the message is delivered should change. Perhaps the way to approach delivering such EBM is just to say: we are all different, we are all diverse and this what will probably work for most of us but not all of us?

I leave with a quote from Rod Tucker: "the stress of worrying about what to eat and drink is more likely to bring about an early demise than trying to change our current dietary habits".

Right, now where is that cream bun.