Why Can’t Medicine Make Up Its Mind?
The Problem:
[It] seems like an endless series of contradictory health findings. First they tell us a medication is safe, then they say it’s not. First they say women should get screened for mammograms at 40, then not. And so on to what vitamins we should take, what foods we should eat, and even how many glasses of water we should drink.
Thomas Goetz’s take:
As frustrating as these shifts can be in isolation, taken together they reflect an effective system. Every revision and new recommendation is an attempt to put forward the best available information.
My take:
This is all the more reason not to lock people into cookbook guides that rely on 5-year-old data.
(Hint: Like comparative effectiveness is likely to do.)
When I studied research design for my PhD program, the professor explained that there are rarely individual studies that turned up “smoking guns” in research. Typically a series of studies, using a variety of methods, will (over time) allow findings to accumulate into a preponderance of evidence from which to draw a conclusion. For instance, at that time (1994) there were over 50,000 different studies that pointed to the fact that smoking was unhealthy.
Perhaps medicine can’t make up its mind because various policy agendas are funding policy oriented “research” that drives results with statistical analysis on dodgy samples that fail to take biological mechanisms into account because the biology itself remains a mystery.
I remember when there was a big scare about the cholesterol in eggs. Then a few years later, another study came out about how eggs were good for you.
I think the lesson is to do everything in moderation. (Not sure how that applies to compartative effectiveness, but it works for eggs.)
Most research in medicine is still very crude — in part because of the limits on testing in humans. The vast majority of what appears in JAMA or NEJM would never be accepted for publication by an economics journal, for example.
So you get contradictory findings because the studies aren’t very good to begin with.
I agree with Joe. There is a lot of crap that gets published in medical journals.
One problem with medical research is that published studies often rely on data that has been cherry-picked. Articles based on data showing a new drug compound in a bad light is unlikely to be submitted to a medical journal by a researcher. Furthermore, there has always been an institutional bias, where journals prefer to publish studies with positive findings over studies showing no result or an ineffective compound.
Here’s a slightly different look at the same issue.
“Health Care Reform: Why Science and Law Do Not Mix”
http://tinyurl.com/SciLawDontMix