Abstract
OBJECTIVE: Rapid identification of high-risk and low-risk patients presenting to the emergency department (ED) influences clinical management and can help optimise patient outcomes as well as resource allocation. This study aims to externally validate the Risk Stratification in the Emergency Department in Acutely Ill Older Patients (RISE UP) score in adult patients in the ED with suspected infection. Furthermore, generalisability was assessed by comparing the discriminatory ability of the RISE UP with the quick Sequential Organ Failure Assessment (qSOFA) as well as the Modified Early Warning Score (MEWS) and National Early Warning Score (NEWS). DESIGN: Retrospective cohort study. SETTING: Single-centre study in the ED of a tertiary, university-affiliated hospital. PARTICIPANTS: Adult patients with suspected infection presenting at the ED for internal medicine from 2016 to 2022. OUTCOMES: The primary outcome was all-cause 30-day mortality. Secondary outcomes were all-cause 14-day mortality, 7-day mortality and intensive care unit (ICU) admission. METHODS: Prognostic performance was evaluated using discrimination (area under the receiver operating characteristic curve (AUC)) and a calibration plot. RESULTS: Of the included 5038 ED visits, there was a 30-day mortality of 7.1%. Discrimination of RISE UP for 30-day mortality was good (AUC 0.809; 95% CI 0.786 to 0.832) and significantly higher than that for the other risk scores: qSOFA (AUC 0.675; 95% CI 0.644 to 0.707), MEWS (AUC 0.688; 95% CI 0.658 to 0.718) and NEWS (AUC 0.725; 95% CI 0.696 to 0.754) (p<0.001). For 14-day and 7-day mortality, RISE UP had the highest AUC, but NEWS performed best for ICU admission. The RISE UP score was well calibrated and had significantly better discriminatory ability in older patients aged ≥65 years (AUC 0.772; 95% CI 0.738 to 0.806; p<0.001) and patients with sepsis (AUC 0.746; 95% CI 0.695 to 0.798; p<0.05) compared with the other scores. Low-risk patients with a RISE UP score of <5% yielded a negative predictive value of 97.7% (95% CI 97.2 to 98.1) and a sensitivity of 79.3% (95% CI 74.7 to 83.4). CONCLUSIONS: The RISE UP score outperformed the qSOFA, MEWS and NEWS in predicting 30-day mortality. It is generalisable to an adult infection-specific cohort and may facilitate distinction between high-risk and low-risk patients in the ED, particularly to rule out poor outcomes.