Total cases (n=82,269) A–C, cases performed in males (n=36,022) D–F and females (n=46,247) G–I. Expanded OSS defined physiologic stress induced by surgery as 1 (very low), 2 (low), 3 (moderate), 4 (high) and 5 (very high). Frailty assessed by Risk Analysis Index scores of ≤20 robust (R), 21–29 normal (N), 30–39 frail (F), and ≥40 very frail (VF). Small sample size for very frail patients undergoing OSS1 and OSS5 procedures shown with dashed gray line.