Impact of weekend admission on in-hospital mortality in severe community-acquired pneumonia patients in Japan

Abstract Background and objective Little is known about the consequences of weekend admission on the quality of care in patients with severe community‐acquired pneumonia. We compared the outcomes of weekend versus weekdays' admission for these patients on risk‐adjusted mortality. Methods Using a large nationwide administrative database, we analysed patients with severe pneumonia who had been hospitalized in 1044 acute care hospitals between 2012 and 2013. We compared risk‐adjusted in‐hospital mortality of guideline‐concordant care between patients admitted weekdays and patients admitted on weekends. Results The study sample comprised 17 342 patients admitted on weekdays and 6190 patients admitted on weekends. The mortality rate of the weekend admission group was significantly higher than that of the weekday admission group (23.7% vs 20.5%; P < 0.001). Even after adjusting for baseline patient severity and need for urgent care, weekend admissions were associated with higher mortality (odds ratio: 1.10; 95% confidence interval: 1.02–1.19). The implementation rates of guideline‐concordant microbiological tests (including sputum cultures and urine antigen tests) were significantly lower in the weekend admission group. These tests were found to be associated with lower in‐hospital mortality. Conclusion Our findings showed that weekend admission was associated with increased mortality in patients with severe community‐acquired pneumonia in Japan. This may have been influenced by lower implementation of microbiological testing.