Background: Our study aimed to investigate the prognostic value of a novel inflammatory index, systemic immune-inflammation index (SII), with the clinical outcomes of patients infected with coronavirus disease 2019 (COVID-19).Methods We evaluated a cohort study of COVID-19 patients (18–95 years old) in Tongji Hospital of Huazhong University of Science and Technology from January 28th 2020 to February 29th 2020. The enrolled patients were divided into two groups (including low-SII group and high-SII group) according to the cut-off point which is analyzed by receiver operating characteristic (ROC) curve. Univariate and multivariate COX regression analysis were performed to identify the factors associated with the outcomes of patients with COVID-19 infection. The primary and secondary outcome were in-hospital mortality and the development of acute respiratory distress syndrome (ARDS), respectively.Results A number of 326 adult patients (43.87% males, 61.22 ± 0.86 years) were enrolled in the final analyses. There were 147 cases (45.09%) died in hospital and 116 patients (35.58%) developed ARDS. ROC curve analysis indicated that the SII had a greater prediction accuracy in predicting the in-hospital mortality (area under the curve [AUC] = 0.789, sensitivity = 69.90%, specificity = 70.80%) and the development of ARDS (AUC = 0.736, sensitivity = 67.80%, specificity = 71.10%). Kaplan-Meier analysis revealed that patients in high-SII group had a greater risk of adverse clinical outcomes (all P < 0.001). The multivariate Cox regression analysis indicated that elevated SII was found as the risk predictor of in-hospital mortality (hazard ratio [HR] = 2.839, 95% confidence interval [CI] = 1.116–7.222, P = 0.028) and the developed ARDS (HR = 6.832, 95%CI = 2.583–18.074, P < 0.001). Additional significant independent predictor for adverse outcomes was the lymphocyte proportion. What’s more, it suggests that the invasive mechanical ventilation performed in the early stage of the disease progression may be beneficial for patients.Conclusion SII, a novel biomarker, might be a remarkable prognostic indicator to assess the in-hospital mortality and the development of ARDS in patients with COVID-19 and help for clinical risk assessment.
Systemic Immune-Inflammatory Index predicts prognosis of patients with COVID-19: a retrospective study