London School of Hygiene & Tropical Medicine

Both papers investigate the 'weekend effect' -  that patients admitted to hospital over the weekend are at an increased risk of death.  However, the findings suggest that this overshadows a much more complex pattern of weekly changes in quality of care

Studies on the weekend effect have had a major, and at times contentious, impact on health policy. Policy makers, including the UK Secretary of State and Department of Health have explicitly attributed the weekend effect to reduced availability of hospital doctors at the weekend, concluding that changes to doctors' employment contracts will be required to deliver high quality care seven days a week. However, evidence about the quality of care at the weekend compared with weekdays, or whether there is a direct link between mortality and the availability of consultants remains largely speculative.

In the first study, a research team led by the University of Birmingham found no association between weekend mortality and senior doctor staffing levels, a factor often linked to the weekend effect. The second study, which looked specifically at acute stroke care, found no difference in 30 day post-admission survival between weekends and weekdays. However, the researchers reported several patterns of weekly variation in the quality of stroke care, both by day of the week and time of day, noting in particular that patients admitted overnight on weekdays had lower odds of survival.

The two papers add evidence to a report published last week suggesting that weekend mortality differences might be attributable to how sick patients are on admission, rather than the quality of their care.

Writing in a comment piece in The Lancet, Professor Nick Black from the London School of Hygiene & Tropical Medicine discusses the implications the studies. He points to many factors that may help explain the increased risk of mortality at the weekends, not least that patients are sicker, and says more research is needed that focuses on other outcomes and patients' experiences. He writes: "In the past few years, politicians, the media, clinicians, and managers have become increasingly interested in the risks involved in being admitted to hospital at weekends. 

"Widespread interest in England about the possible dangers of being admitted to hospital at weekends has prompted several studies into why this might be, three of which have been published this week. 

"Despite many claims about the quality of care at weekends and strong beliefs about the reasons for this, we need to remain open to the true extent and nature of any such deficit and to the possible causes. Jumping to policy conclusions without a clear diagnosis of the problem should be avoided because the wrong decision might be detrimental to patient confidence, staff morale, and outcomes."

Publication

• Nick Black, Is hospital mortality higher at weekends? If so, why? The Lancet. doi: 10.1016/S0140-6736(16)30505-0