Risk score for mortality due to COVID-19: a prospective temporal validation cohort study in the emergency department of a tertiary care hospital.

OBJECTIVES

To validate a previously described hospital emergency department risk model to predict mortality in patients with COVID-19.

MATERIAL AND METHODS

Prospective observational noninterventional study. Patients aged over 18 years diagnosed with COVID-19 were included between December 1, 2020, and February 28, 2021. We calculated a risk score for each patient based on age 50 years (2 points) plus 1 point each for the presence of the following predictors: Barthel index 90 points, altered level of consciousness, ratio of arterial oxygen saturation to fraction of inspired oxygen 400, abnormal breath sounds, platelet concentration 100 × 109/L, C reactive protein level 5 mg/dL, and glomerular filtration rate 45 mL/min. The dependent variable was 30-day mortality. We assessed the score's performance with the area under the receiver operating characteristic curve (AUC).

RESULTS

The validation cohort included 1223 patients. After a median follow-up of 80 days, 143 patients had died; 901 patients were classified as having low risk (score, 4 points), 270 as intermediate risk (5-6 points), and 52 as high risk ( 7 points). Thirty-day mortality rates at each risk level were 2.8%, 22.5%, and 65.4%, respectively. The AUC for the score was 0.883; for risk categorization, the AUC was 0.818.

CONCLUSION

The risk score described is useful for stratifying risk for mortality in patients with COVID-19 who come to a tertiary-care hospital emergency department.