Factors Defining the Development of Severe Illness in Patients with COVID-19: A Single-Center, Retrospective, Observational Study

Abstract Objective Early triage of patients with coronavirus disease 2019 (COVID-19) is pivotal in managing the disease. However, data on the risk factors for the development of severe disease remains scant. Here, we report a clinical risk score system for severe illness and highlight possible protective factors, which might inform proper treatment strategies.Methods We conducted a retrospective, single-center, observational study at the JinYinTan Hospital from January 24,2020 to March 31, 2020. We evaluated the demographic, clinical, and laboratory data and performed a 3-fold cross-validation to split the data into training set and validation set. We then screened the prognostic factors for severe illness using the Least Absolute Shrinkage and Selection Operator (LASSO) and logistic regression, and finally conducted a risk score to estimate the probability of critical illness in the training set. Data from the validation set were used to validate the score. Furthermore, the clinical factors of those patients who recovered were compared with those who did not recover from the rapidly worsened illness. We then employed logistic regression tools to delineate the possible protective factors.Results A total of 302 patients were included. From 47 potential risk factors, 6 variables were measured as the risk score: sex(female) (OR, 0.372; 95%CI, 0.211-0.655), Chest Computed Tomography abnormality (OR, 1.90; 95%CI, 1.36-2.66), neutrophil value (OR, 1.33; 95%CI, 1.18-1.50), neutrophil to lymphocyte ratio (OR, 1.23; 95%CI, 1.14-1.34), lactate dehydrogenase (OR, 1.01; 95%CI, 1.006-1.012), albumin (OR, 0.77; 95%CI, 0.71-0.84). The mean AUC of development cohort was 0.82 (95% CI, 0.81-0.92) and the AUC of validation cohort was 0.894 (95% CI, 0.78-0.95). Our comparison data from patients who rapidly worsened but recovered with those who did not showed that 4 variables were predictive factors: Prealbumin (OR, 1.028; 95%CI, 1.010-1.057), percentage of lymphocytes (OR, 1.213; 95%CI, 1.062-1.385), lactate dehydrogenase (OR, 0.984; 95%CI, 0.973-0.996), Prothrombin ativity (OR, 1.065; 95%CI, 1.018-1.115).Conclusion and Relevance In this study, we developed a predictive risk score and highlight 4 factors that might predict recovery from suddenly worsened illness. This report may help define the potential of developing critical illness and recovery prospects in patients with rapidly worsened condition.