The weekend effect refers to higher rates of adverse outcomes experienced by patients admitted on the weekends. Researchers sought to determine whether adoption of clinical standards for emergency hospital care put forth by the National Health Service in England is associated with the degree to which weekend mortality is increased. Using data from 123 Trusts, they found no association between adoption of these clinical standards and the extent of the weekend effect. This finding suggests that adoption of these standards is unlikely to reduce mortality among patients admitted to the emergency department on the weekend.

The weekend effect is a term used to describe the finding that patient outcomes are worse during off hours. In keeping with prior research, this single center study found that patients admitted as emergencies on nights and weekends were at increased risk of mortality and that the risk was greatest among patients admitted on weekend nights.

Previous research has shown that patients admitted to the hospital on the weekend are at increased risk for worse outcomes, including mortality. This retrospective study examined more than 3 million emergency admissions to 140 hospital trusts in England between April 2013 and February 2014. Patient arrival times were recorded by day of the week and nighttime versus daytime. Using administrative data and standard risk adjustment, mortality rates were higher for patients arriving during the week on Wednesday and Thursday nights. Risk-adjusted mortality rates were also found to increase for patients arriving over the weekend from daytime on Saturday through nighttime on Sunday. However, when researchers adjusted for arrival by ambulance, higher mortality was statistically significant only for those patients arriving at the hospital during the day on Sunday. Investigators suggest that prior research supporting the weekend effect is overly reliant on administrative data, which may not accurately characterize illness severity. It is often debated whether the weekend effect could be due to factors related to the system of care (i.e., reduced staffing on weekends) or patient factors (i.e., increased severity of illness of patients admitted on the weekend). An Australian study sought to answer this question and found that certain diagnoses appeared to be associated with higher mortality for weekend admissions, largely due to health system factors.