AUTHOR=Li Yang , Kong Yanlei , Ebell Mark H. , Martinez Leonardo , Cai Xinyan , Lennon Robert P. , Tarn Derjung M. , Mainous Arch G. , Zgierska Aleksandra E. , Barrett Bruce , Tuan Wen-Jan , Maloy Kevin , Goyal Munish , Krist Alex H. , Gal Tamas S. , Sung Meng-Hsuan , Li Changwei , Jin Yier , Shen Ye 

TITLE=Development and Validation of a Two-Step Predictive Risk Stratification Model for Coronavirus Disease 2019 In-hospital Mortality: A Multicenter Retrospective Cohort Study

JOURNAL=Frontiers in Medicine

VOLUME=Volume 9 - 2022

YEAR=2022

URL=https://www.frontiersin.org/journals/medicine/articles/10.3389/fmed.2022.827261

DOI=10.3389/fmed.2022.827261

ISSN=2296-858X

ABSTRACT=OBJECTIVES: An accurate prognostic score to predict mortality for adults with COVID-19 infection is needed to understand who would benefit most from hospitalizations and more intensive support and care. We aimed to develop and validate a two-step score system for patient triage, and to identify patients at a relatively low level of mortality risk using easy-to-collect individual information.
DESIGN: Multicenter retrospective observational cohort study.
SETTING: Four health centers from Virginia Commonwealth University, Georgetown University, the University of Florida, and the University of California, Los Angeles.
PATIENTS: Coronavirus Disease 2019-confirmed and hospitalized adult patients.
MEASUREMENTS AND MAIN RESULTS: We included 1,673 participants from Virginia Commonwealth University (VCU) as the derivation cohort. Risk factors for in-hospital death were identified using a multivariable logistic model with variable selection procedures after repeated missing data imputation. A two-step risk score was developed to identify patients at lower, moderate, and higher mortality risk. The first step selected increasing age, more than one pre-existing comorbidities, heart rate >100 beats/minute, respiratory rate ≥30 breaths/minute, and SpO2 <93% into the predictive model. Besides age and SpO2, the second step used blood urea nitrogen, absolute neutrophil count, C-reactive protein, platelet count, and neutrophil-to-lymphocyte ratio as predictors. C-statistics reflected very good discrimination with internal validation at VCU (0.83, 95% CI 0.79–0.88) and external validation at the other three health systems (range, 0.79 to 0.85). A one-step model was also derived for comparison. Overall, the two-step risk score had better performance than the one-step score.
CONCLUSIONS: The two-step scoring system used widely available, point-of-care data for triage of COVID-19 patients and is a potentially time- and cost-saving tool in practice.