High-sensitivity C-reactive protein to lymphocyte ratio as a novel biomarker for predicting postoperative delirium in elderly patients with hip fractures: A retrospective cohort study

Emerging evidence suggests that inflammatory and immune biomarkers may serve as prognostic indicators across diverse clinical contexts. This study sought to investigate the association between the high-sensitivity C-reactive protein to lymphocyte ratio (hs-CLR) and the risk of postoperative delirium in elderly patients undergoing surgery for hip fractures. We conducted a retrospective cohort study of patients aged 60 years or older who underwent surgical management for hip fractures at a university-affiliated tertiary hospital between January 2021 and December 2024. The primary exposure was hs-CLR, and the primary endpoint was 30-day postoperative delirium, ascertained through systematic review of inpatient medical records and confirmed by outpatient and telephone follow-up. The relationship between hs-CLR and delirium was explored using restricted cubic spline modeling, receiver operating characteristic curve analysis, univariate comparisons, and multivariate logistic regression. A total of 582 patients (192 males, 390 females; mean age 73.8 ± 8.4 years) were included. The 30-day incidence of delirium was 21.3% (124/582). Both unadjusted and adjusted restricted cubic spline analyses revealed a significant nonlinear dose-response association between hs-CLR and delirium risk (P