Why Are Weekend Hospital Admissions Associated with Excess Mortality?

The well-known association between weekend hospital admission and higher 30-day mortality — the so-called “weekend effect” — has been attributed widely to inadequate hospital staffing on weekends; however, in-hospital mortality generally is no higher on weekends than on weekdays. To explore other explanations for the weekend effect, investigators in the U.K. examined linked data on demographics, comorbidities, admission characteristics, and results of 15 common blood tests for more than 500,000 emergency admissions to four university hospitals from 2006 through 2014.

Significantly more patients admitted on public holidays and weekends than on weekdays died within 30 days (5.8% and 5.1% vs. 4.7%). Results of routine blood tests (particularly …