In a shocking discovery an in depth analysis of the performance of all doctors across all areas and at all grades show that exactly 50% were performing below average. Despite the reassuring news that 50% were performing above average surely someone should be looking into this?
Well maybe not, by definition 50% will be below and 50% above average as the average is simply the mid point of the range of performances. The headline is eye-catching but meaningless it may be that all the doctors are great or they may all be incompetent but still 50% will be below average!
Why do I bring this up well it is a simple example of how all of us can get caught out by data and it's misuse in our day to day lives. A perennial issue in my household is the use of vitamin C supplements for the treatment of the common cold. There are two schools of thought:
Mine: that there is no evidence and it doesn't work. This is based on numerous studies and good hard science.
My wife's and my daughter's: yes it does and for added measure the raspberry flavored ones work best according to my daughter. This is based on nothing.
Well as you may guess this results in us having a good healthy supply of vitamin C.
In fairness there is a bit of evidence it may help in extreme conditions such as mountaineers and soldiers in the arctic but this doesn't really apply to our household.
Does it matter? The doses they are taking do no harm and the placebo effect means they get some benefit. I think it does matter because a huge amount of money is spent on it. In 2009 £180 million was spent in the UK on vitamin C and multivitamins. In total around £650 million was spent on vitamins and dietary supplements of which only a tiny proportion would give any real benefit.
'It's a free country' I hear you say. Well yes it is and people, including me, waste money on all sorts of stuff and they should be free to do so, but here's the rub; they should know they're wasting their money. In my opinion, all vitamins and other such supplements should clearly state what benefit they are proven to have.
Most of us don't really have time to check the studies on such things and hence we are at risk of being caught out by marketing or misuse of data. If your interested the Mayo Clinic in the US provide a simple summary on the data. Basically the only thing vitamin C really works for is vitamin C deficiency (scurvy) and, unless your a 17th century sailor, this really shouldn't be an issue!