Background and Goal of Study: Admission to hospitals on weekend is generally considered to be increased mortality compared with that on weekday. Previous meta-analysis has demonstrated the mortality rate of patients who admitted on weekends in ICU was higher than that on weekdays. However, the results of other studies focusing on patients who admit to wards except ICU was less conclusive. We performed a systematic review and meta-analysis to compare the mortality for the patients on the weekend with the weekday admitted to hospital.
Materials and methods: We followed the Meta-analysis of Observational Studies in Epidemiology (MOOSE) guidelines. A comprehensive search of the literature was conducted using electronic databases. The primary outcome was in-hospital mortality. We performed subgroup analysis by dividing patients into 6 categories type of admission: patients who had stroke; cardiovascular disease; upper gastrointestinal haemorrhage; medical disease; mixed medical and surgical disease; and who received operation. Both Bayesian and frequentist random-effects meta-analysis were used. The median posterior risk ratio (RR) with the corresponding 95% bayesian credible intervals (BCIs) and the pooled RR with the corresponding 95% confidence intervals (CIs) were calculated. The heterogeneity of the results was examined by I2 test.
Results and discussion: 72 studies including 55,053,719 participants met our inclusion criteria. Weekend admission was associated with increased mortality compared with the weekday admission (Bayesian RR=1.17; 95%BCI: 1.10- 1.24, frequentist RR=1.15; 95% CI: 1.15-1.16;
P < 0.0001, I2 = 98.8%). Subgroup analysis revealed that weekend admission was at higher risk of death than weekday admission in patients in all categories except for the patients who received operation. There are at least two potential explanations for our results. First, these differences reflect poorer quality of care in hospital at the weekend, and second, patients admitted on at weekend could be more severely ill than those admitted on at weekday. The reason for the lack of a significant association between postoperative patients and mortality might be explained by the low number of studies included, and hence a lack of power to detect any statistical significance.
Conclusions: Our systematic review shows that weekend admission is associated with higher mortality compared with weekday admission.