Phase angle as an indicator of nutritional status and prolonged hospitalization risk in inpatients with neurological conditions: A cross‐sectional study

BACKGROUND: Malnutrition is prevalent among inpatients with neurological conditions and is associated with adverse outcomes. This study identified determinants of phase angle (PhA) and its association with prolonged length of stay (LOS). METHODS: This cross-sectional study enrolled 365 inpatients with neurological conditions. Bioelectrical impedance analysis-derived PhA was measured at admission. Nutritional status was assessed using Nutritional Risk Screening 2002 (NRS-2002) and Subjective Global Assessment. PhA was categorized (<6° vs ≥6°) for description and modeled as continuous in regression. Linear regression identified PhA determinants. Logistic regression assessed the association between PhA and prolonged LOS (≥19 days). Receiver operating characteristic analysis compared discrimination of PhA and NRS-2002. PhA below the reference range (<6°) was associated with prolonged LOS (P = 0.043). After adjusting for age, sex, and disease category, lower PhA was independently associated with prolonged LOS (OR = 0.810 per 1° increase; 95% CI, 0.680-0.966; P = 0.019); however, this association was no longer significant in the fully adjusted model or in the sensitivity analysis using continuous LOS. The NRS-2002 showed better discrimination for prolonged LOS (AUC = 0.626; P < 0.001). CONCLUSION: Lower PhA was associated with prolonged hospitalization in the partially adjusted model, but not in the fully adjusted model or sensitivity analyses. PhA may complement existing screening approaches such as the NRS-2002.