Association between inflammatory index and mortality in advanced lung cancer patients with chronic bronchitis: A cross-sectional study

Background Chronic bronchitis (CB) threatens public health, and its prognosis is related to inflammation and nutritional status. The advanced lung cancer inflammation index (ALI) integrates these two factors, but its association with CB prognosis remains unknown. Methods We collected data from NHANES (1999 - 2018) and used the National Death Index to calculate mortality until December 31, 2019. Kaplan - Meier analysis explored the ALI - mortality relationship in CB patients. Weighted univariate and multivariate Cox models, adjusting for relevant factors, further examined this relationship. Restricted cubic spline analysis estimated the non - linear association, and subgroup and sensitivity analyses ensured result reliability. Results Involving 2103 CB patients, elevated ALI was associated with reduced death risk. An inverse J - shaped non - linear relationship was found between ALI and all - cause mortality, with a turning point of 96.33 (p < 0.0001). Below 96.33, increased ALI meant lower death risk; above it, increased ALI led to higher risk. Findings were consistent across subgroups and stable in sensitivity analysis. Conclusion This study reveals a novel link between elevated ALI and reduced death risk in CB patients. Maintaining ALI within an optimal range is crucial for long - term survival. ALI's dynamic changes can help clinicians set personalized criteria for better long - term outcomes.