Kaplan-Meier curve for 90-day outcomes grouped based on SI ≤ 43 (high specificity cut-off), SI between 43 and 101 (high-sensitivity cut-off), and SI ≥ 101 (reference). The risk of death in patients with an SI ≤ 43 was significantly greater [HR 2.61 (95% CI 1.06, 6.48), P = 0.038]. For patients with an SI between 43 and 101, the HR for death was 1.71 (95% CI 0.74–3.94) (P = 0.21). Abbreviations: CI, confidence interval; HR, hazard ratio; SI, Sarcopenia Index