Prevalence and factors associated with malnutrition in critically ill elderly patients: a retrospective cohort study

Abstract

Abstract Background Malnutrition is a common but often under-recognized condition in critically ill older adults. Age-related physiological decline, including reduced nutritional reserve and increased vulnerability to stress, may exacerbate its impact; however, data focusing specifically on elderly intensive care unit (ICU) populations remain limited. This study aimed to determine the prevalence of malnutrition and identify associated factors in critically ill elderly patients. Methods We conducted a retrospective cohort study of patients aged ≥ 60 years admitted to the medical ICU, Faculty of Medicine, Chiang Mai University, Thailand, between 1 January 2022 and 31 December 2023. Malnutrition was defined using the Nutrition Triage 2013 (NT2013) tool. Multivariable logistic regression was performed to identify factors associated with malnutrition, reported as adjusted odds ratios (aORs) with 95% confidence intervals (CIs). Results Among 411 patients, 41.4% were malnourished at ICU admission. Compared with non-malnourished patients, those with malnutrition had greater illness severity (APACHE II 22 [IQR 18, 25] vs. 19 [IQR 15, 23], p < 0.001) and higher ICU mortality (17.7% vs. 2.5%, p < 0.001). Independent factors associated with malnutrition included lower body mass index (aOR 0.91, 95% CI 0.86–0.96, p < 0.001), male (aOR 1.67, 95% CI 1.08–2.57, p = 0.021), higher total bilirubin (aOR 1.12, 95% CI 1.01–1.24, p = 0.039), lower serum albumin level (aOR 0.48, 95% CI 0.34–0.67, p < 0.001), and higher APACHE II score (aOR 1.09, 95% CI 1.04–1.13, p < 0.001). Conclusion Malnutrition is highly prevalent among critically ill elderly patients and is associated with greater illness severity and increased ICU mortality. Early identification through systematic nutritional screening and appropriate management, particularly in patients with identified factors associated with malnutrition, may help mitigate adverse outcomes.