Improved mortality outcomes over time for weekend emergency medical admissions

Multiple studies have suggested an association between weekend hospital admissions and mortality. These have been limited by potential residual confounders and a lack of explanation of causation.

We previously attributed adverse weekend outcomes to higher acuity; we have re-examined this question for all emergency medical admissions to our institution from 2002 to 2014.

We divided admissions by a weekday or weekend (Friday to Sunday) hospital arrival. We utilised a multivariate logistic regression model, to determine whether the latter was independently predictive of 30-day in-hospital mortality.

There were 82,368 admissions in 44,628 patients over the 13-year period. Of admissions, 37.4% occurred at the weekend. The Acute Illness Severity Score, the Charlson Co-morbidity Index and the Chronic Disabling Disease Score were similar by a weekday or weekend admission. The multivariable logistic regression showed no increase in 30-day in-hospital mortality for weekend admissions, odds ratio 1.07 (95% confidence interval 0.98 to 1.16) (p = 0.11). Since the inception of the AMAU, the per patient mortality for a weekend admission has declined from 13.5% in 2002 to 4.4% in 2014. This represents a relative risk reduction of 67.9% with a number needed to treat of 10.8. Outcomes improved similarly for weekday and weekend admissions.

No increase in 30-day in-hospital mortality for weekend admissions was found in this study. There has been a substantial reduction in mortality for both weekday and weekend admissions over time.