Lymphocyte-albumin-neutrophil ratio predicting short-term and long-term mortality risk in elderly patients with...

Inflammatory response and nutritional status are closely related to the prognosis of critically ill patients, especially in elderly patients with delirium, where the situation is more complex. This study aims to explore the relationship between the Lymphocyte-Albumin-Neutrophil Ratio (LANR) and short- and long-term mortality risks in elderly delirium patients, providing valuable insights for clinical management.

This study utilized the MIMIC-IV ICU public database to identify elderly delirium patients based on ICD-9 and ICD-10 codes. First, a qualitative approach was employed using Restricted Cubic Spline (RCS) analysis to visually illustrate the potential relationship between LANR and 30-day and 365-day mortality rates. Second, from a quantitative perspective, a Cox proportional hazards model was used for multivariable regression analysis to assess the independent effect of LANR on short- and long-term mortality risks after adjusting for other confounding factors. Additionally, to further explore heterogeneity, subgroup analyses were conducted, and forest plots were generated to examine potential significant interactions.

A total of 1,804 elderly delirium patients were extracted from the MIMIC-IV database, with a mean age of 77.6 ± 7.9 years and an ICU length of stay of 3.3 days [IQR 1.8-6.7 days]. Restricted cubic spline analysis revealed a linear relationship between LANR and 30-day mortality risk reduction in elderly delirium patients (P for non-linearity>0.05). Although LANR showed a non-linear relationship with 365-day mortality risk, the risk decreased progressively as LANR levels increased. Cox multivariable regression analysis, after adjusting for covariates, indicated that higher LANR levels (T2, 0.21 < LANR≤0.47) were associated with an 26% reduction in short-term mortality risk and an 18% reduction in long-term mortality risk [HR_30-day = 0.74, 95% CI: 0.60-0.91, p = 0.004; HR_365-day = 0.82, 95% CI: 0.70-0.96, p = 0.013]. Extremely high LANR levels (T3, LANR>0.47) were associated with a 45% reduction in short-term mortality risk and a 40% reduction in long-term mortality risk [HR_30-day = 0.55, 95% CI: 0.44-0.69, p < 0.001; HR_365-day = 0.60, 95% CI: 0.51-0.71, p < 0.001]. Subgroup analysis further identified a significant interaction between LANR and vasopressor use in relation to 365-day mortality (p = 0.018 < 0.05).

The inflammatory marker LANR is closely associated with increased short- and long-term ICU mortality risk in elderly delirium patients, highlighting its potential as a prognostic tool in clinical practice.