Supplementary Material for: Frailty predicts postoperative complications following pancreaticoduodenectomy

Introduction: Frailty is a clinically recognizable state of decreased reserve and function across physiologic systems, characterized by an inability to cope with acute stressors. A validated modified frailty index (mFI) was used to evaluate the impact of frailty on postoperative complications following pancreaticoduodenectomy. Methods: Data from consecutive patients undergoing pancreaticoduodenectomy from 2011-2020 was collected retrospectively at a high-volume tertiary care hepatopancreatobiliary hospital. Based on an 11-item mFI, patients were grouped by high (≥0.27) and low mFI. The main outcome was postoperative complications (Clavien-Dindo classification). The impact of frailty on complications was analyzed evaluating baseline and operative characteristics using multivariable logistic regression. Secondary outcomes included postoperative mortality, length of hospital stay, and intensive care unit admission, which were analyzed using univariable logistic regression. Results: There were 64/554 patients (12%) with high mFI. Low and high mFI had similar characteristics, including proportion of pancreatic adenocarcinoma (low mFI = 247/490 (50%) versus high mFI = 31/64 (48%), p=0.767), intermediate or hard pancreatic texture (low mFI = 75/191 (39%) versus high mFI = 6/19 (32%), p=0.512), operative room time (low mFI = 370 minutes versus high mFI = 368 minutes, p=0.630), and drain placement (low mFI = 355/490 (72%) versus high mFI = 48/64 (75%), p=0.642). The mFI score was an independent predictor for the development of any type of postoperative complications (OR 1.44, 95% CI 1.02 to 2.10) and major postoperative complications (OR 1.44, 95% CI 1.05 to 1.98) by multivariable analysis. High mFI patients had a higher 90-day mortality rate (high mFI = 7/64 (11%) versus low mFI = 20/490 (4.1%), p=0.017), longer median length of hospital stay (high mFI = 11 days versus low mFI = 8 days, p=0.016), higher rate of intensive care unit admission (high mFI = 47/64 (73%) versus low mFI = 211/490 (43%), p<0.001). Conclusion: Among patients that are considered surgical candidates, the mFI can identify those at high risk of developing postoperative complications. This tool can be used to accurately discuss postoperative risk with patients undergoing pancreaticoduodenectomy.