The problem with evidence based medicine

I don't have a lot of patience for woo at the best of times, and I have almost none for woo when it comes to treating people with real illnesses. The only patience I have for it is that placebo can be a Good Thing, and if woo doesn't cost too much, does no harm and induces a nice, effective placebo, I'm down with that. However, it often costs lots, is potentially harmful, and placebo may not be enough to cure any given ill. It's at it's absolute worst when it stops people also seeking evidence based medicine.

However, one of the reasons woo gets a look-in is that people have a gut feeling that evidence based medicine isn't always right. Most people know that we have very individual responses to various medicines, they know that very often their own symptoms don't match the text book, or are not even close. So the woo that offers individually tailored "treatments" look attractive.

There's been more than one occasion lately where I've found myself arguing with prevailing medical wisdom, based entirely on anecdotal evidence. Anecdata does not a theory make. However, basic trial and error about what triggers which, and then which relieves what is also empirical evidence. It can't be entirely ignored because it isn't conducted by a person in a white coat. It certainly says nothing about the way the same things might operate in the next person, but if it's in direct conflict with what conventional, evidenced based medicine is telling us, something's got to give.

For example, both gout and diabetes have come up a few times in my meanderings recently. I have neither, so I'm merely collecting anecdata here, and comparing it with the received wisdom of evidence based medicine. In both examples, people who have monitored their own health for a length of time have found wildly different things exacerbate or improve their condition from each other, and from what the doctors have told them.

There is nothing surprising in this. Evidence based medicine is based on statistical inferences from samples. The results are averaged across participants. Evidence based medicine is an excellent approximation of what happens to the Average Person, and Average Person doesn't exist. The trouble is, nowhere near enough doctors and other health professionals really understand this. They have a list of foods that cause gout in Average Person, but the people I know that have it have entirely different triggers from each other and from that list. The list isn't wrong, it's just that it's the most common triggers, averaged across all the people the studies have been conducted on. That's fine, as long as the doctor understands that, and presents it as such - as a starting point for your own trial and error to find out what your problem foods are. Same story with diabetes and blood sugar levels.

I'd like to see medicine start to engage more fully in the study of difference. To follow up the studies describing the average symptoms/responses/profiles with careful analysis of the differences between subgroups and even individuals. I'd also like to see it engage patients more fully in the understanding of their own bodies. It's not that no-one does it now (or I wouldn't have my anecdata), it's just that it's not mainstream for patients, and it's barely even tolerated by the medical profession, nevermind encouraged.  

I will back existing evidence based medicine over woo any day, but it's important to remember how it's done, what it's really telling us, and that at the end of the day, as Brian said, "You're all individuals!".

(As a footnote, this is a description of evidence based medicine as it should be. I'm not even beginning to address deliberate misrepresentations of data for the purposes of profit and/or power - that's a rant in and of itself.)