Absolute mortality risk assessment of COVID-19 patients: the Khorshid COVID Cohort (KCC) study

Marateb, Hamid Reza; von Cube, Maja; Sami, Ramin; Haghjooy Javanmard, Shaghayegh; Mansourian, Marjan; Amra, Babak; Soltaninejad, Forogh; Mortazavi, Mojgan; Adibi, Peyman; Khademi, Nilufar; Sadat Hosseini, Nastaran; Toghyani, Arash; Hassannejad, Razieh; Mañanas, Miquel Angel; Binder, Harald; Wolkewitz, Martin

BACKGROUND: Already at hospital admission, clinicians require simple tools to identify hospitalized COVID-19 patients at high risk of mortality. Such tools can significantly improve resource allocation and patient management within hospitals. From the statistical point of view, extended time-to-event models are required to account for competing risks (discharge from hospital) and censoring so that active cases can also contribute to the analysis. METHODS: We used the hospital-based open Khorshid COVID Cohort (KCC) study with 630 COVID-19 patients from Isfahan, Iran. Competing risk methods are used to develop a death risk chart based on the following variables, which can simply be measured at hospital admission: sex, age, hypertension, oxygen saturation, and Charlson Comorbidity Index. The area under the receiver operator curve was used to assess accuracy concerning discrimination between patients discharged alive and dead. RESULTS: Cause-specific hazard regression models show that these baseline variables are associated with both death, and discharge hazards. The risk chart reflects the combined results of the two cause-specific hazard regression models. The proposed risk assessment method had a very good accuracy (AUC = 0.872 [CI 95%: 0.835–0.910]). CONCLUSIONS: This study aims to improve and validate a personalized mortality risk calculator based on hospitalized COVID-19 patients. The risk assessment of patient mortality provides physicians with additional guidance for making tough decisions.