Geriatric Nutritional Risk Index as a Prognostic Factor for Mortality in Elderly Patients with Moderate to Severe Traumatic Brain Injuries

Background: The Geriatric Nutritional Risk Index (GNRI) is a simple and objective screening tool for clinicians to screen patients' nutritional status based on serum albumin level and their weight and height. The original study had divided patients based on GNRI into quartiles of nutritional risk for death: a no-risk group (GNRI >98), a low-risk group (GNRI 92-98), a moderate-risk group (GNRI 82 to <92), and a major-risk group (GNRI <82). Given that the patients generally sustained traumatic brain injury (TBI) in an acute condition, the study aimed to explore whether GNRI presents a prognostic value for the mortality outcome of these patients.

Methods: From January 1, 2009, to December 31, 2019, 581 elderly patients with moderate to severe TBI, which was defined as sustaining a head Abbreviated Injury Scale ≥3, was included in the study population. The collected data included age, sex, body mass index, serum albumin levels at admission, preexisting comorbidities, Glasgow Coma Scale, and Injury Severity Score. The primary outcome in the comparison was in-hospital mortality.

Results: Multivariate logistic regression analysis revealed that GNRI, ESRD, and ISS were significant independent risk factors for mortality in patients with moderate to severe TBI. When subgrouping the study population into four nutritional risk categories according to the quartile deviation as Q1 (GNRI <85, n = 145), Q2 (GNRI 85 to <93.8 n = 145), Q3 (GNRI 93.8 to 103, n = 145), and Q4 (GNRI >103, n = 146), Q1 patients had a significantly longer LOS in hospital (25.2 days vs 18.6 days, respectively; p = 0.004) and higher mortality rate (28.3% vs 11.7%, respectively; p < 0.001) than Q4 patients. The mortality rate was significantly higher in Q1 patients than in Q4 patients (OR, 2.8; 95% CI, 1.14-6.78; p = 0.021).

Conclusion: This study revealed that the GNRI is a significant independent risk factor and a promising simple assessment tool for mortality in elderly patients with moderate to severe TBI.