The association between the geriatric nutritional risk index (GNRI) and postoperative outcomes after hip fracture in older adults: a prospective cohort study

The GNRI is an objective nutritional status screening tool. This study aimed to investigate the prognostic value of GNRI in predicting long-term outcomes of geriatric hip fracture patients. We prospectively enrolled patients aged ≥ 65 years who underwent hip fracture surgery between November 2018 and November 2019. Admission GNRI was categorized into quartiles (Q1 ≤ 96, Q2 96–101, Q3 101–104, Q4 > 104). Patients were followed up at 30 days, 120 days, 1 year and 3 years postoperatively. Cox proportional hazards model and ROC curve were performed to evaluate mortality risk; multiple logistic regression identified the value for recovery of pre-fracture mobility. Multiple linear regression and generalized estimating equations assessed associations between GNRI and EQ-5D utility scores. Of the 1092 patients, 947 were eligible for the research. The ROC of GNRI for predicting mortality was set. (AUC 0.726, 95% CI 0.687–0.766) Patients in Q2, Q3 and Q4 had significantly lower mortality risks (HRs 0.68, 95% CI 0.48–0.97; 0.47, 95% CI 0.31–0.72; and 0.23, 95% CI 0.13–0.42, respectively) comparing to Q1. Even after applying propensity score matching (PSM), individuals with higher GNRI still remained lower mortality risk. (HRs 0.56, 95% CI 0.34–0.91 and 0.55, 95% CI 0.36–0.85) Compared to Q1, patients in Q4 had a significantly increased possibility of achieving recovery at 1-year (OR 1.71, 95% CI 1.03–2.83, P = 0.037) and 3-year (OR 1.77, 95% CI 1.02–3.07, P = 0.042) follow-up. Admission GNRI was positively associated with EQ-5D utility scores at all follow-ups’ assessments (all P < 0.001), patients with higher GNRI exhibited better quality of life. The GNRI upon admission is potentially a reliable and independent prognostic indicator of long-term mortality, functional status and quality of life in Chinese geriatric hip fracture patients. This study was prospectively registered at ClinicalTrials.gov (Identifier: NCT03184896, Registration Date (First Posted): 2017-06-14) prior to the enrollment of participants.