Association of Combined Nutritional Risk and Oral Frailty Assessment with Postoperative Complications in Older Surgical Patients: A Pilot Cohort Study

Abstract

Introduction: Postoperative complications are common in older adults and are influenced by frailty-related factors. This study examined whether the combined assessment of nutritional risk and oral frailty was associated with postoperative complications in older surgical patients. Methods: We retrospectively analyzed 200 patients aged ≥65 years who underwent elective surgery under general anesthesia at Kyorin University Hospital (July–October 2021). Nutritional risk was defined as a Geriatric Nutritional Risk Index (GNRI) <98, and oral frailty as an Oral Frailty Index-8 score ≥4. Patients were stratified into four groups: no risk, oral frailty only, nutritional risk only, and both conditions. The primary outcome was complications of Clavien–Dindo grade ≥II. Multivariable logistic regression analyses were performed, including a sensitivity analysis using log-transformed intraoperative blood loss as an alternative indicator of surgical invasiveness. Results: Median age was 75 years (interquartile range 70-80), and 52.5% were male. Complications occurred in 32.0% overall: 22.4% (no risk), 25.9% (oral frailty only), 45.0% (nutritional risk only), and 50.0% (both conditions) (p < 0.01). In multivariable models adjusted for age, sex, and American Society of Anesthesiologists Physical Status, nutritional risk (adjusted odds ratio [aOR] 2.72, 95% confidence interval [CI] 1.13-6.51) and combined risk (aOR 2.85, 95% CI 1.12-7.23) were significant predictors. After additional adjustment for operative time, only nutritional risk remained significant (aOR 2.86, 95% CI 1.11-7.36), whereas in a sensitivity analysis using log-transformed intraoperative blood loss, both nutritional risk alone (aOR 3.12, 95% CI 1.21-8.01) and combined risk (aOR 3.26, 95% CI 1.21-8.75) remained significantly associated with complications. Conclusions: Preoperative nutritional risk assessed by the GNRI was consistently associated with postoperative complications, whereas oral frailty alone was not. Although the combined presence of nutritional risk and oral frailty showed the highest crude complication burden, its association varied according to the indicator of surgical invasiveness. These findings support the importance of nutritional assessment in perioperative risk stratification in older surgical patients.