Intended for healthcare professionals


Making sense of the evidence for the “weekend effect”

BMJ 2015; 351 doi: (Published 05 September 2015) Cite this as: BMJ 2015;351:h4652
  1. Paul Aylin, professor of epidemiology and public health
  1. 1Dr Foster Unit, School of Public Health, Imperial College London, London EC4Y 8EN, UK
  1. p.aylin{at}

Sicker patients at the weekend, but even after adjustment for this their risk of death is higher

In their analysis of 2013-14 English hospital administrative data, Freemantle and colleagues again find an increased risk of death in patients admitted at a weekend compared with weekdays.1 Their analysis combines both emergency and elective admissions and updates their earlier study.2 They confirm a persistent “weekend effect” in England, which they claim is “not otherwise ignorable,” and add to a substantial body of literature demonstrating this phenomenon both nationally3 4 5 and internationally.6 7 8

The findings of such studies and the resultant media coverage are being used by politicians to bring about changes in working practices,9 but against a strong background of criticism of these kinds of statistics.10 At first glance, there is conflicting evidence about whether the weekend effect exists at all.11 12 However, closer scrutiny shows that apparently “contradictory” studies tend to be smaller, carried out in single hospitals, and lack statistical power. Death after hospital admission, particularly for a planned surgical procedure, is relatively rare, and small studies simply don’t have the numbers to be able …

View Full Text

Log in

Log in through your institution


* For online subscription