BACKGROUND: A recent systematic review recommends against the use of any of the current COVID-19 prediction models in clinical practice . To enable clinicians to appropriately profile and treat suspected COVID-19 patients at the emergency department (ED), externally validated models that predict poor outcome are desperately needed .

OBJECTIVE: Our aims were to identify predictors of poor outcome, defined as mortality or ICU admission within 30 days, in patients presenting to the ED with a clinical suspicion of COVID-19, and to develop and externally validate a prediction model for poor outcome .

METHODS: In this prospective, multi-center study, we enrolled suspected COVID-19 patients presenting at the EDs of two hospitals in the Netherlands . We used backward logistic regression to develop a prediction model . We used the area under the curve (AUC), Brier score and pseudo-R2 to assess model performance . The model was externally validated in an Italian cohort .

RESULTS: We included 1193 patients between March 12 and May 27 2020, of whom 196 (16.4 %) had a poor outcome . We identified 10 predictors of poor outcome: current malignancy (OR 2.774; 95% CI 1.682-4.576), systolic blood pressure (OR 0.981; 95% CI 0.964-0.998), heart rate (OR 1.001; 95% CI 0.97-1.028), respiratory rate (OR 1.078; 95% CI 1.046-1.111), oxygen saturation (OR 0.899; 95% CI 0.850-0.952), body temperature (OR 0.505; 95% CI 0.359-0.710), serum urea (OR 1.404; 95% CI 1.198-1.645), C-reactive protein (OR 1.013; 95% CI 1.001-1.024), lactate dehydrogenase (OR 1.007; 95% CI 1.002-1.013) and SARS-CoV-2 PCR result (OR 2.456; 95% CI 1.526-3.953). The AUC was 0.86 (95% CI 0.83-0.89), with a Brier score of 0.32 and, and R2 of 0.41 . The AUC in the external validation in 500 patients was 0.70 (95% CI 0.65-0.75).

CONCLUSION: The COVERED risk score showed excellent discriminatory ability, also in an external validation . It may aid clinical decision making, and improve triage at the ED in health care environments with high patient throughputs.