High platelet-to-lymphocyte ratio predicts poor survival of elderly patients with hip fracture

Abstract

Purpose: The platelet-to-lymphocyte ratio (PLR) has been extensively studied in various diseases. However, the relationship between PLR and hip fracture remains unknown. The aim of this study was to evaluate whether PLR would be an independent prognostic factor in elderly hip fracture patients. Methods: Between January 2014 and December 2018, a retrospective cohort study was conducted in a orthopaedic centre, China. A total of 460 hip fracture patients were included. PLR was calculated as the ratio of platelet to lymphocyte counts and divided into high PLR group (≥ 189) and low PLR group (< 189) by using the receiver operating characteristic (ROC) curve. The relationship between PLR and one year all-cause mortality rate was assessed by univariate and multivariate Cox proportional hazard models. Further subgroup analysis stratified by different clinical and biological characteristics was performed to make the results more accurate. Results: After a median follow-up of 32.0 months (range, 12.0–75.4), 92 patients (mortality rate: 20.0%) died within one year. PLR was significantly higher in dead patients compared with alive patients (p < 0.05), and high PLR group also had a high mortality rate (32.21% vs. 14.15%, p < 0.001). After multivariate adjustment, high PLR remained an independent predictor for one year all-cause mortality (adjusted hazard ratio (HR) 1.56, 95% confidence interval (CI) 1.02–2.41, p = 0.041). Moreover, advanced age (HR 1.05, 95% CI 1.01–1.08), male (HR 1.62, 95% CI 1.06–2.45), CCI ≥ 2 (HR 2.83, 95% CI 1.64–4.89), conservative treatment (HR 5.94, 95% CI 3.71–9.73), low haemoglobin level (HR 1.02, 95% CI 1.01–1.04), and low albumin level (HR 1.07, 95% CI 1.02–1.13) were independent risk factors for survival. Furthermore, subgroup analysis results were consistent with the main findings in most stratified groups. Conclusion: This study highlights that high PLR (≥ 189) is associated with increased one year all-cause mortality in elderly hip fracture patients. As PLR is a simple indicator that can be calculated from the blood routine test, it can be easily performed in usual clinical practice.