The weekend effect: now you see it, now you don’t

Those who yearn for a world in which policies are based on a systematic and dispassionate assessment of the evidence can find little encouragement in the ongoing debate about the safety of hospitals at weekends. Almost nothing is clear in this tangled tale. It began when the health secretary, Jeremy Hunt, claimed on the BBC Today programme that there were 6000 avoidable deaths each year and a lack of weekend cover by consultants was a key factor.1 Yet the evidence to support this claim was elusive. Sometimes the Department of Health pointed to a 2012 paper on hospital mortality.2 Other times, and contrary to the government’s code of practice on use of statistics, they mentioned a (then) yet to be published paper in The BMJ.3 The problem was that, while both did identify an increase in deaths among those admitted at weekends, neither attributed it to a shortage of medical staff. Both identified numerous possible explanations, including various data artefacts. Indeed, the second paper stated explicitly that “to assume that [these deaths] are avoidable would be rash and misleading.”3 …