Tuesday, 30 June 2009

Public advice: we need more information

I keep finding myself pondering government advice, and how we really need more information if the genuine aim of this advice is to change people's behaviour for the better. Take the UK government's advice on drinking alcohol safely, where men are advised to drink no more than 4 units of alcohol a day (so 28 per week, 21 for women). Now, I don't believe for a second that this particular figure is based on anything more than guesswork and the perceived need to provide some (any) figure, but it is useful for illustrating my wider point, which is that with any advice like this, how exactly are the public supposed to translate the number into action? You see, I can think of at least 4 completely plausible interpretations of this 28-units-per-week advice:

  • If I drink 28 units per week then I will definitely come to no harm
  • If I drink 28 units per week then there is a 95% chance I will come to no harm
  • If I drink 28 units per week then there is a 50% chance I will come to no harm
  • If I drink any more than 28 units per week I will definitely come to harm

So which is it? This really matters, because each interpretation would lead me to respond in a totally different way. This is something I keep finding myself thinking about with any sort of official advice on behaviour: we need more facts about how the advice is arrived at if we are to make sensible decisions about whether and how to change our behaviour. Or at least I do: others might be happy to follow dogma ;o)

Finally, big cheers to Google. When I searched for "five a day" its top result was "five a day = 5.78703704 × 10-5 hertz". Superb!

1 comments:

owlrigh said...

Popped over from copenhagenize. I like your train of thought! Not very clear with their recommendations, eh? The interpretation would depend upon how much you drink to start off with, in all likelihood, and lean more towards #1 in an attempt to rationalise that you're boozing it up every night.