Saturday, July 21, 2012

Evidence-Based Practices. [EBP1]

He's right, darn it. Source.


Admittedly, the blog has been neglected.  I blame my new bicycle.  If it were not such a pleasant machine, I would be more than happy to spend my time inside, telling the internet how I feel about things.

I have, however, been thinking about possible writing topics.  I would like to begin discussing evidence-based practice and practices, but I am not sure about the most efficient method by which to proceed.  I believe that I shall make a series of it, rather than having a giant article outlining all the evidence-based practices (EBP) I find interesting (the composition could take days, or even weeks).  According to Wikipedia, an EBP is one which relies upon reliable, repeated data gathering rather than one which follows rules, single observations or custom.

I'll attempt to elaborate here, though I will disclose that you should take what I say with a grain of salt.  I am not an expert, nor am I fully awake at the moment.  A practice following rules is a simple concept, like crossing the street at marked intersections or crosswalks as opposed to illegally jaywalking.  A practice following custom would be simply doing something "the way it has always been done".  An anecdote from a friend springs to mind.  An elderly man used to dispose of charcoal ash in a garbage can full of paper because that was the way he had always done it, meaning it was his custom to do so.  His garage eventually burned when hot coals and old newspaper did what hot things and newspaper usually do together.  This would be an hilarious example of a practice based upon custom rather than evidence (because although disposal safely happened previous to this incident, there is considerable evidence that newspaper will readily combust).

I would argue the trickiest counter-example above is the "single observation".  Not the trickiest concept, but the hardest to ignore.  Here, I recall a radio interview with a researcher studying the effects of yoga on weight loss objectives.  He found a trend that the human metabolism tended to slow for yoga practitioners, and that those who do not change their eating habits are at risk of weight gain.  Naturally, since it was a call-in show, the phone lines were inundated with calls from yoga practitioners who had lost weight.  The researcher had not said that yoga stopped weight loss, but that was how people heard it.  He ended up sounding like a broken record when explaining that he noticed a general trend and not an absolute rule.  In short, counterexamples do not disprove general trends, it just proves that outliers exist.  Similarly, anecdotal evidence does not necessarily imply a rule or trend exists.  For example, you probably shouldn't eat your ground beef rare just because that's the way your Uncle Jimmy does it, and he's never had a problem.

In fact, some EBP fly in the face of common sense.  A statistical study in Australia suggests that mandatory helmet laws for cyclists actually increases the number of cycling-related injuries.  It would seem that mandatory helmet laws greatly decrease the number of cyclists on the road, largely because we are a vain people and our hairstyle is important to us.  It has been hypothesized that as the number of cyclists on Australian roads decreased so much that motor vehicles became less accustomed to dealing with them, which caused a higher incidence of accidents.  Personally, I always wear my helmet to prevent brain trauma in the event of a crash.  However, this study leads me to believe that mandatory helmet laws are a bad idea, because that is what the evidence suggests.

I'll leave you to think about that last point.  If you weren't aware, the chief coroner for Ontario recently presented a report calling for mandatory helmet laws, because every cycling-related death in the past five years has involved head trauma.  It's an interesting dichotomy to think about, but based on the evidence, I'll continue to argue against helmet laws, but I'll wear one myself.


Edit (2014-01-11):
Title says it all, really.  Source.