FIB‐4 Index and APRI Score Predict Short‐ and Long‐Term Mortality in Hospitalized COVID‐19 Patients: A 4‐Year Follow‐Up Study

Noninvasive liver fibrosis indices, including the Fibrosis-4 (FIB-4) and AST-to-platelet ratio index (APRI), are widely used in clinical practice. We investigated whether admission FIB-4 and APRI, together with inflammatory markers and comorbidities, chest CT severity, and intensive care unit (ICU) admission, were associated with short- and long-term mortality in hospitalized COVID-19 patients. We retrospectively analyzed 691 adults hospitalized with PCR-confirmed COVID-19 between October and November 2020. Demographic characteristics, comorbidities, admission laboratory parameters, chest CT severity, length of stay, and intensive care unit (ICU) admission were recorded. Mortality during hospitalization, within 100 days, and within 4 years was obtained from the hospital database. FIB-4 and APRI were calculated using routine laboratory parameters. The cohort included 410 women (59.3%) and 281 men (40.7%); 79 patients (11.4%) required ICU admission, and 36 (5.2%) had malignancy. In-hospital, 100-day, and 4-year mortality rates were 12.0%, 14.6%, and 23.3%, respectively. Across all time points, mortality was associated with older age, higher inflammatory markers (including CRP), higher neutrophil counts and neutrophil-to-lymphocyte ratio (NLR), higher FIB-4 and APRI scores, severe chest CT findings, ICU admission, and comorbidities including malignancy, hypertension, and chronic renal failure. Lymphocyte count, hemoglobin, and platelet count were inversely associated with mortality. Admission inflammatory markers and noninvasive fibrosis indices (FIB-4 and APRI), combined with comorbidities and disease severity (CT and ICU requirement), are strong predictors of short- and long-term mortality up to 4 years in hospitalized COVID-19 patients.