BackgroundMalnutrition is shown to be associated with worse outcomes among surgical patients, yet its postdischarge outcomes in trauma patients are not clear. This study aimed to evaluate both index admission and postdischarge outcomes of geriatric trauma patients who are at risk of poor nutritional status. MethodsThis is a secondary analysis of the prospective observational American Association of Surgery for Trauma Frailty Multi-institutional Trial. Geriatric (≥65 years) patients presenting to 1 of the 17 Level I/II/III trauma centers (2019–2021) were included and stratified using the simplified Geriatric Nutritional Risk Index (albumin [g/dL] + body mass index [kg/m2]/10) into severe (simplified Geriatric Nutritional Risk Index <5), moderate (5.5> simplified Geriatric Nutritional Risk Index ≥5), mild level of nutritional risk (6> simplified Geriatric Nutritional Risk Index ≥5.5), and good nutritional status (simplified Geriatric Nutritional Risk Index ≥6) and compared. ResultsOf the 1,321 patients enrolled, 22% were at risk of poor nutritional status (mild: 13%, moderate: 7%, severe: 3%). The mean age was 77 ± 8 years, and the median [interquartile range] Injury Severity Score was 9 [5–13]. Patients at risk of poor nutritional status had greater rates of sepsis, pneumonia, discharge to the skilled nursing facility and rehabilitation center, index-admission mortality, and 3-month mortality (P < .05). On multivariable analyses, being at risk of severe level of nutritional risk was independently associated with sepsis (adjusted odds ratio 6.21, 95% confidence interval 1.68–22.90, P = .006), pneumonia (adjusted odds ratio 4.40, 95% confidence interval 1.21–16.1, P = .025), index-admission mortality (adjusted odds ratio 3.16, 95% confidence interval 1.03–9.68, P = .044), and 3-month mortality (adjusted odds ratio 8.89, 95% confidence interval 2.01–39.43, P = .004) compared with good nutrition state. ConclusionNearly one quarter of geriatric trauma patients were at risk of poor nutritional status, which was identified as an independent predictor of worse index admission and 3-month postdischarge outcomes. These findings underscore the need for nutritional screening at admission.