Impact of weekend admission on in-hospital mortality among U.S. adults, 2003-2013.

PURPOSE: Over the past decade, the media, politicians, practitioners, and researchers paid increasing attention to the risks involved in hospital admission at weekends. This study examined the impact of weekend admission on in-hospital mortality among U.S. adults and by sex, age, race/ethnicity, and disease category and tracked changes from 2003 to 2013.

METHODS: Over 50 million hospital discharge data came from 2003 to 2013 National Inpatient Sample. Cox regressions were performed to estimate the hazard ratios of in-hospital mortality associated with weekend admission, adjusting for individual and hospital characteristics and National Inpatient Sample sampling design.

RESULTS: Compared to weekday admissions, weekend admissions were associated with increased in-hospital morality risk by 5% among all inpatients. Young adults (2.7%) had lower incremental mortality risk than middle aged (5.3%) and older adults (5.2%). Among the 10 leading causes of death, patients hospitalized at weekends due to malignant neoplasms (12.1%), diabetes mellitus (11.7%), and heart diseases (8.2%) had the highest incremental mortality risk. The estimated weekend effects tended to be more prominent among inpatients with higher assessed mortality risk. Incremental morality attributable to weekend hospitalization decreased from 6.9% in 2003 to 2.5% in 2013.

CONCLUSIONS: Weekend admissions were associated higher in-hospital mortality, but the impact declined during 2003-2013.