Research Square · Oct 22, 2026
Incremental Prognostic Value of the Geriatric Nutritional Risk Index in Mechanically Ventilated Older ICU Patients: A Retrospective Cohort Study
By Caliskan DK, Ergul RB
Background The Geriatric Nutritional Risk Index (GNRI) is a simple marker of nutrition-related risk in older adults, but its prognostic value in mechanically ventilated older intensive care unit (ICU) patients remains uncertain. We evaluated the association of GNRI with 28-day mortality and its incremental prognostic value beyond conventional severity scores. Methods This single-center retrospective cohort study included 285 ICU patients aged ≥ 65 years who received invasive mechanical ventilation between January 2025 and July 2026. Patients were classified as having nutritional risk (GNRI ≤ 98) or no nutritional risk (GNRI > 98). The primary outcome was 28-day mortality; extubation failure was evaluated as a secondary outcome. Multivariable logistic regression and receiver operating characteristic analyses were performed, and GNRI was compared with APACHE II and SOFA scores. Results Twenty-eight-day mortality was higher in patients with nutritional risk than in those without risk (52.6% vs. 14.0%; p < 0.001). GNRI-defined nutritional risk remained independently associated with mortality (adjusted OR 2.50, 95% CI 1.01–6.25; p = 0.049). GNRI showed moderate discrimination for mortality (area under the curve [AUC] 0.767, 95% CI 0.708–0.826) and outperformed SOFA (AUC 0.701; p = 0.010). Adding GNRI to SOFA increased the AUC to 0.772 (p = 0.016). Although GNRI was associated with extubation failure in unadjusted analysis, this association did not persist after multivariable adjustment. Conclusions GNRI was independently associated with 28-day mortality in mechanically ventilated older ICU patients and provided incremental prognostic information beyond SOFA. GNRI may serve as a simple complementary tool for early mortality risk stratification, but not as a standalone predictor of extubation failure.