Association between the Geriatric Nutritional Risk Index and the Risk of Readmission in Older Inpatients: A Systematic Review and Meta-Analysis

Background: The Geriatric Nutritional Risk Index (GNRI) is associated with readmission risk in older hospitalized patients, but evidence is from single-center studies.Methods Searched Cochrane Library, Web of Science, PubMed, and Embase until October 23, 2024, for case-control or cohort studies on GNRI and readmission in patients aged ≥60. Study quality was assessed using the Newcastle-Ottawa Scale (NOS). Analyses were performed in Stata 15.0, employing random- or fixed-effects models based on heterogeneity (I2≥50%, P < 0.05). Effect sizes were reported as relative risk (RR) or standardized mean difference (SMD) with 95% confidence intervals (CI). Subgroup and sensitivity analyses were conducted.Aim: To quantify the association between GNRI and readmission risk, total hospital length of stay, and intensive care unit (ICU) stay in older hospitalized patients.Results Thirty-six studies were included. Twelve studies (n = 234,116) confirmed a lower readmission risk for the high-GNRI group (RR = 0.60, 95% CI: 0.53–0.68; I2 = 70.8%). Twenty-six studies (n = 30,461) showed shorter total hospital and ICU stays.Conclusion A lower GNRI is significantly associated with higher readmission risk and longer total hospital and ICU stays in older inpatients, supporting its role as a biomarker for adverse outcomes.