High prevalence of iron deficiency and predictive value of nutritional risk scores in critically ill geriatric emergency patients: a prospective cross-sectional study

Malnutrition and iron deficiency (ID) are prevalent yet frequently underdiagnosed in critically ill geriatric emergency patients, contributing to anemia and adverse clinical outcomes. However, data on ID prevalence and its association with nutritional status in this population remain scarce. This prospective cross-sectional study aimed to investigate the prevalence of ID and its correlation with nutritional risk scores among critically ill geriatric emergency patients. We enrolled 443 critically ill geriatric emergency patients (≥ 60 years) admitted to the emergency department. ID was defined as serum ferritin < 100 µg/L, or 100-299 µg/L with transferrin saturation < 20%. Nutritional risk was assessed using mNUTRIC and NRS-2002 scores. The prevalence of ID was 47.4%, significantly higher in anemic patients than non-anemic patients (57.1% vs. 46.8%; P = 0.029). Patients with ID exhibited lower hemoglobin, albumin, and serum iron levels but higher mNUTRIC and NRS-2002 scores (all P < 0.05). Multivariate analysis identified mNUTRIC score (OR = 1.551; 95% CI: 1.315-1.829), NRS-2002 score (OR = 1.381; 95% CI: 1.132-1.685), and albumin level (OR = 0.909; 95% CI: 0.875-0.944) as independent risk factors for ID. The mNUTRIC score demonstrated superior predictive performance (AUC = 0.744; cutoff ≥ 4; sensitivity 79.5%, specificity 71.7%) compared to NRS-2002 (AUC = 0.670) and albumin (AUC = 0.639).Nearly half of critically ill geriatric emergency patients present with ID, which is closely linked to nutritional risk. The mNUTRIC score (≥ 4) can effectively guide targeted iron screening in this high-risk, critically ill population.