The Association Between Geriatric Nutritional Risk Index and Readmission Within Six Months in Elderly Heart Failure Patients: A Retrospective Cohort Study

Background: The geriatric nutritional risk index (GNRI) is a valuable tool that may predict the prognosis of elderly patients with heart failure (HF). Malnutrition and low GNRI scores have been associated with a higher risk of hospitalization and mortality. This study aimed to investigate the association between GNRI and 6-month readmission for HF in elderly Chinese patients.Materials and Methods: The study utilized data from hospitalized HF patients by combining electronic medical records from the PhysioNet restricted health data database with external outcome data. In our study, we used the GNRI as the independent variable and assessed its association with the risk of readmission within 6 months. The main analytical methods were multivariable Cox regression, stratified analysis with interaction, threshold effect analysis, and Kaplan-Meier survival curves.Results: This study involved 767 elderly HF patients, 61.3% of whom had malnutrition. In the threshold analysis, HF patients' 6-month readmission risk was significantly reduced with increasing GNRI, with a hazard ratio (HR) and 95% confidence interval (CI) of 0.99 (0.97.1). Malnutrition group was associated with a higher risk of readmission within 6 months for HF patients in analyses that were controlled for confounding factors, with HRs and their 95% CI of 1.17 (0.99, 1.38), 1.18 (1, 1.4), and 1.44 (1.08,1.93), respectively. Subgroup analysis showed that GNRI levels had a consistent impact on outcome events, unaffected by covariates.Conclusions: GNRI was negatively correlated with the outcome event of readmission within 6 months in elderly HF patients. Malnutrition group showed a higher risk of readmission within 6 months.