Adjusting for illness severity shows there is no difference in patient mortality at weekends or weekdays for emergency medical admissions

Background: Patients admitted to hospitals over the weekend appear to have a higher risk of death compared to weekday admissions, but the reasons remain unclear. Unlike previous studies, we use a standardised mandated vital signs physiological based measure of sickness known as the National Early Warning Score (NEWS) to investigate this “weekend effect” for emergency admissions. Aim: To determine if weekend admissions are (1) sicker as measured by their index NEWS, (2) have an increased risk of death and (3) have less favourable monitoring of their vital signs compared with weekday admissions. Methods Analysis of 58481 emergency adult medical admissions in three acute hospitals with electronic (index) NEWS recorded within 24 hours of admission. Results: Admissions over the weekend had higher index NEWS (weekend: 2.24 vs weekday: 2.05, p<0.001) with a higher risk of death (weekend: 260/3911 6.65% vs weekday: 696/12683 5.49%, Risk Ratio=1.10, 95%CI: 1.01 to 1.19, p=0.023) which was no longer seen after adjusting for the index NEWS (risk ratio=1.00, 95%CI 0.92 to 1.08, p=0.94). The time to index NEWS was earlier (-0.41 hours 95%CI -0.47 to -0.35, p<0.001) for weekend admissions whilst the number of NEWS recorded over their hospital stay was not dissimilar (-0.03 95%CI -0.39 to 0.34, p=0.892). Conclusions: Patients who have an acute admission over the weekend with a NEWS recorded within 24 hours are sicker, have earlier clinical assessments, and after adjusting for their illness severity do not appear to have a higher risk of death compared to weekday admissions.