Outcomes of community-acquired pneumonia using the Pneumonia Severity Index versus the CURB-65 in routine practice of emergency departments.

Background: The Pneumonia Severity Index (PSI) and the CURB-65 score assess disease severity in patients with community-acquired pneumonia (CAP). We compared the clinical performance of both prognostic scores according to clinical outcomes and admission rates. Methods: A nationwide retrospective cohort study was conducted using claims data from adult CAP patients presenting to the emergency department (ED) in 2018 and 2019. Dutch hospitals were divided into three categories: "CURB-65 hospitals" (n=25), "PSI hospitals" (n=19) and hospitals using both ("no-consensus hospitals", n=15). Main outcomes were hospital admission rates, intensive care unit admissions, length of hospital stay, delayed admissions, readmissions and all-cause 30-day mortality. Multilevel logistic and Poisson regression analysis were used to adjust for potential confounders. Findings: Of 50 984 included CAP patients, 21 157 were treated in CURB-65 hospitals, 17 279 in PSI hospitals and 12 548 in no-consensus hospitals. The 30-day mortality was significantly lower in CURB-65 hospitals versus PSI hospitals (8.6% and 9.7%, adjusted odds ratio (aOR) 0.89, 95% CI: 0.83-0.96, p=0.003). Other clinical outcomes were similar between CURB-65 hospitals and PSI hospitals. No-consensus hospitals had higher admission rates compared to the CURB-65 and PSI hospitals combined (78.4% and 81.5%, aOR 0.78, 95% CI: 0.62-0.99). Interpretation: In this study, using the CURB-65 in CAP patients at the ED is associated with similar and possibly even better clinical outcomes compared to using the PSI. After confirmation in prospective studies, the CURB-65 may be recommended over the use of the PSI since it is associated with lower 30-day mortality and is more user-friendly.