Mortality in out-of-hours emergency medical admissions--more than just a weekend effect.

Mortality among emergency medical admissions to hospital is higher for admissions at the weekend than on weekdays; this also holds true for certain specific conditions. However, it is unknown whether that effect is limited to weekends. This study calculated mortality in emergency medical admissions for each day of the week, and compared mortality at weekends with weekdays, at nights with days, and in all out-of-hours periods with in-hours in a UK district general hospital. Total mortality was increased for admissions on Mondays, at night, and in all out-of-hours periods; late in-hospital mortality (after seven days) remained increased when the initial admission occurred on Mondays, at night or out of hours. It is likely that illness severity as well as resource and organisational factors are involved.