Background: Several studies have shown increased mortality and readmission rate in patients admitted to hospitals over the weekend. This “weekend effect” has been well-described for several medical conditions and has been attributed to several factors. However, a comprehensive analysis of clinical outcomes of patients discharged over the weekend has not been performed. The objective of this study was to examine clinical outcomes of patients discharged over the weekend. We report a novel phenomenon “reverse weekend effect.”
Methods: A large administrative database, the Vizient database, was utilized for this retrospective outcomes analysis study. Discharge data from 2015-2017 was included in the study. Patients were compared for outcomes between those discharged during the weekday that included Monday through Friday and those discharged over the weekend that included Saturday and Sunday. Outcome variables analyzed included mortality, readmission rate, ICU admission, direct costs and length of stay.
Results: A total of over 12 million discharges (12,577,819) discharges were included in the study during the study period. Analysis of number of discharges by discharge day showed a very interesting trend of increase in discharges every day from Monday through Friday with the highest number of discharges on Friday. Discharges dropped significantly over the weekend by about 30%. A total of 9,891,990 discharges were noted during the weekday and 2,685,829 discharges over the weekend. Analysis of discharges by discharge day revealed that mortality decreases from Monday to Friday. Mortality is higher over the weekend compared to weekday (2.93% weekend vs 2.03% weekday; p<0.0001). Patients discharged during weekday showed higher ICU utilization (16.20% weekday vs 14.27% weekend; p<0.0001), higher readmission rate (5.52% weekday vs 5.35% weekend; p<0.0001); higher length of stay (5.73 ± 8.63 days during weekday vs 4.33 ± 11.62 days during weekend; p<0.0001) and significantly higher costs ($ 9459 ± 18,308 weekday vs $ 7893 ± 14,131 weekend; p<0.0001). Stratification by discharge severity of illness showed that weekend discharges had significantly higher proportion of minor (20.95% weekday vs 25.12% weekend; p<0.0001) and moderate illness severity. Significantly lower major and extreme severity (11.38% weekday vs 8.73% weekend; p<0.0001) illness discharges were noted over weekend compared to weekday.
Conclusions: This study analyzed clinical outcomes observed in patients discharged over the weekend compared to weekday. A novel phenomenon “reverse weekend effect” was examined with readmission, length of stay, costs, ICU utilization rate significantly better in patients discharged over weekend compared to weekday. Only mortality was observed to be worse over weekend. Further analysis revealed that this effect may be due to differences in discharge illness severity of patients.