Development and Validation of a Laboratory Score Based on Blood Cell Parameters to Predict Survival in Hospitalized COVID-19 Patients (preprint)

ABSTRACT

Background: A relevant portion of patients with disease caused by the ‘severe acute respiratory syndrome coronavirus 2’ (COVID-19) experience poor outcome and several laboratory tests have been proposed to predict disease severity. Among others, dramatic changes in peripheral blood cells have been described. We developed and validated a laboratory score based on blood cell parameters to predict survival in hospitalized COVID-19 patients.Methods: We retrospectively analyzed 1619 blood cell counts from 226 COVID-19 patients, consecutively admitted to our institution, to select variables for inclusion in the severity score. The lymphocyte percentage, the immature granulocyte number, the highly fluorescent lymphocyte cell percentage, the neutrophils side fluorescent light, and the lymphocytes fluorescence light intensity were finally selected and the derived score then validated on a separate cohort of 140 COVID-19 patients.Findings: Using ROC curve analysis, a best cut-off for score of 30.6 was derived, which was associated to an overall 82.0% sensitivity (95% CI 78-84) and 82.5% specificity (95% CI 80-84), respectively, for detecting outcome. The score trend effectively separated the patients’ groups, starting on average two weeks before the end of the hospitalization period.Interpretation: The developed scoring system accurately predicted survival in hospitalized COVID-19 patients. As the laboratory parameters employed in the model are easily accessible on the modern haematology analyzers, the proposed score may offer a fast and reliable tool for supporting clinical decisions in COVID-19 patients.Funding Statement None.Declaration of Interests The authors declare no competing interests.Ethics Approval Statement The Institutional Review Board approved the study.