Investigation of the Prognostic Values of the Shock Index and Modified Shock Index in Predicting the Clinical Outcomes in Elderly Hospitalized Patients with Coronavirus Disease-2019

Abstract

Introduction: Advanced age is an independent risk factor for increased mortality in coronavirus disease-2019 (COVID-19). However, the best method for estimating mortality in elderly patients with COVID-19 is still under debate. We performed this study to assess the shock index (SI) and the modified shock index (MSI) for the abovementioned problem. Methods: A retrospective study was conducted including elderly cases (>= 65 years) confirmed with COVID-19 who admitted to a tertiary university hospital between March-December 2020. The SI and MSI at the time of the emergency department visits were used to evaluate the intensive care unit admission, ventilator support, septic shock, and 30-day mortality in all patients. The receiver operating characteristic and area under the curve (AUC) were used to measure the overall ability of SI and MSI to predict clinical outcomes. Results: We recruited 334 consecutive COVID-19 patients with a mean age of 75.2 +/- 7.3 and an almost equal gender distribution [170 males (50.9%)]. In deceased and surviving patients, the SI was 0.66 +/- 0.16 and 0.6 +/- 0.1 (p=0.014), while the MSI was 0.95 +/- 0.22 and 1.09 +/- 0.34 (p=0.003), respectively. In predicting mortality, the AUC of the SI and MSI were 0.590 [95% confidence interval (CI): 0.535 to 0.643] and 0.608 (95% CI: 0.553 to 0.660), respectively. Conclusion: Increased SIs and MSIs are associated with 30-day mortality. SI and MSI can benefit the triage of elderly patients hospitalized for COVID-19. However, it was found that there is no single cut-off value of SI or MSI with optimum accuracy for predicting COVID-19-related clinical outcomes.