Monday, August 9, 2010

Look beyond the statistics

Second, look beyond the statistics. When reports hurl at you statistics like ‘a 30 per cent increase’ or phrases such as ‘a 50 per cent higher risk,’ take a closer look at the exact numbers. Many of us get ‘turned off’ by numbers, but this attitude can prove dangerous: you need to ask yourself what the numbers really mean and how they apply to you? Benjamin Disraeli once remarked that there are three kinds of lies: lies, damned lies and statistics. Remember that statistical methods are simply tools, and they can produce blatantly wrong conclusions unless sensibly used. One common way in which statistics can be misleading pertains to reporting of relative and absolute risk. A headline that screams ‘X Doubles the Risk of Y’ is way off target if your chance of contracting ‘Y’ is one in a million to begin with. Doubling the risk of ‘Y’ only makes it two in a million! The relative risk (doubled) is nothing to worry about if the absolute risk (an increase from one to two in a million) is tiny.

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