Supplementary Material for: Effect of Preoperative Geriatric Nutritional Risk Index on Prognosis in Patients after Surgery for Lower Gastrointestinal Perforation

Introduction: Geriatric Nutritional Risk Index (GNRI) is a reliable index derived from serum al-bumin levels, height, and weight. Although various prognostic factors have been studied, the effect of preoperative nutritional status on surgical outcomes remains unexplored. This study aimed to evaluate the efficacy of the GNRI in predicting postoperative outcomes of lower gastro-intestinal perforation.
Methods: Eighty patients treated at our institution between January 2016 and December 2022 were retrospectively analyzed. This study primarily focused on the correlation between pre-operative GNRI and two key outcomes: postoperative hospital stay duration and 1-year mortality rate.
Results: Our findings revealed a significant association between low GNRI scores and increased 1-year mortality (Odd ratio 4.0, 95% confidence interval [CI] 1.1–16, p=0.025). Kaplan–Meier analysis and log-rank test showed that patients in the low GNRI group had markedly poorer overall survival rates than those in the high GNRI group (12-month survival rate 0.88 [95%CI: 0.75–0.95] vs. 0.65 [95%CI: 0.47–0.78]; p=0.018). Additionally, both univariate and multivariate analyses indicated that lower GNRI scores were associated with prolonged hospital stays.
Conclusion: We showed that a low GNRI score was associated with high mortality and pro-longed hospital stay after emergency surgery for lower gastrointestinal perforation.