FIB-4, APRI, and ALRI as Predictors of COVID-19 Outcomes: Insights from a Large-Scale Study

<b>Background:</b> Simple and cost-effective biochemical markers are still very useful for predicting severity and mortality in COVID-19 patients. This study investigates the association of some inflammatory and also non-invasive biochemical indices of liver function and critical care outcomes of COVID-19 patients. <b>Methods:</b> In this cross-sectional study, a total of 2232 hospitalized COVID-19 patients, regardless of the presence of underlying liver diseases, were followed. Based on the laboratory results at the time of admission, five indices-FIB-4 (Fibrosis-4), NLR (Neutrophil to Lymphocyte Ratio), APRI (Aspartate Aminotransferase to Platelet Ratio), ALRI (Aspartate Aminotransferase to Lymphocyte Ratio), and SII (Systemic Immune-Inflammation)-were calculated. <b>Results:</b> According to the results of multivariate regression, all five indices were predictors of mortality and severity in COVID-19 patients after adjusting for age, sex, comorbidities and BMI. The odds ratios for FIB-4, NLR, APRI, ALRI, and SII to predict mortality were 1.14 (1.07-1.21), 1.07 (1.04-1.1), 1.28 (1.12-1.46), 2.44 (1.76-3.38), and 1.57 (1.13-2.17), respectively. For predicting severity, the odds ratios were 1.22 (1.15-1.30), 1.09 (1.06-1.11), 1.78 (1.44-2.21), 1.73 (1.41-2.14), and 1.27 (1.04-1.57), respectively. Additionally, based on the AUC results, FIB-4 and NLR indices demonstrated the best performance in predicting COVID-19 mortality and severity, respectively. <b>Conclusions:</b> Our results show that the non-invasive biochemical indices of liver function, NLR, and SII can be useful as early predictors of severity and mortality in COVID-19 patients.