Headlines on the BBC News tell us starkly (if somewhat smugly) ' No alcohol safe to drink, global study confirms .' But like all statistically-based stories, the devil is in the detail. First port of call in any such situation is David Spiegelhalter, the Winton Professor of Public Understanding of Risk at Cambridge. And the story,  according to him , is rather different from the scare headlines. He starts by pointing out a bizarre omission in the paper quoted - they only show relative risk, not absolute risk. The trouble with relative risk is that it is often hugely misleading. Imagine the headline 'Murder rate in city increases by 100%'. Wow - that city appears to have hit the ropes, big time. However, that is a relative statistic. We don't know what that 100% represents. Exactly the same data could also be represented by the headline 'One murder last year, two murders this year.' That is a 100% increase. But far less scary sounding. So the paper'...