This systematic review examined 97 studies and over 51 million patients admitted to the hospital on either a weekday or a weekend. The study revealed that patients admitted on a weekend (Friday evening to Monday morning) has about a 20% increased overall mortality compared with those admitted on a weekday (RR = 1.19, 95% confidence interval 1.14-1.23). Extrapolated over the entire U.S., this rate would translate to about 50,000 preventable deaths due to weekend admissions.
Subgroup analysis showed that decreasing staffing on weekends was associated with a higher mortality (RR = 1.16, 95% confidence interval 1.12-1.20). In addition, decreased number and longer delays for interventions on weekends was associated with a higher mortality (RR = 1.11, 95% confidence interval 1.08-1.15).
The other contributing factor may be some heterogeneity on which patients present on weekends versus weekdays. Many of these 97 studies did not define the relative differences in the patient characteristics between the two periods of admission. Regardless of all the factors involved, patients admitted on a weekend have a significantly increased all-cause mortality compared with those admitted on a weekday.