The neutrophil-to-lymphocyte ratio (NLR) after surgery for hip fracture (HF)

Abstract

Background: The NLR is a prognostic factor for outcome and survival in cardiology, oncology and digestive surgery. NLR has not yet been studied in HF.

Methods: Retrospective analysis of a prospective cohort of 247 consecutive patients, older than 65 years, operated for HF. Mortality at 12 months was registered, as the perioperative NLR values.

Results: After hip surgery in the 247 patients (women 71%, median age 85 years, range: 66-102), the mortality was 27.2% [95%confidence interval (CI): 21.4-33.0] at 12 months. Univariate analysis detected four risk factors for mortality: age (Hazard Ratio (HR)--by 10 year-increments: 2.08 [95%CI: 1.37-3.17], P<0.001), male gender (HR: 1.92 [95%CI: 1.17-3.14], P=0.009, MCM (≥3) (HR: 1.71 [95%CI: 1.006-2.92], P=0.047 and NLR>5 at day 5 (HR: 1.8 [95%CI: 1.11-2.94], P=0.002). In multivariate analysis, two factors remained significantly associated with mortality: age (HR: 2.28 [95%CI: 1.49-3.47], P<0.001) and male gender (HR: 2.26 [95%CI: 1.38-3.72], P=0.001). Two independent risk factors of postoperative cardiovascular complications were identified: NLR>5 at day 5 (Odds Ratio (OR): 3.34 [95%CI: 2.33-4.80], P=0.001) and MCM (OR: 3.04 [95%CI: 2.16-4.29], P=0.006). A higher risk of infection was independently associated with a NLR>5 at day 5 (OR: 2.12 [95%CI: 1.44-3.11], P=0.02).

Conclusions: The NLR at fifth postoperative day is a risk factor of postoperative mortality and cardiovascular complications.

Keywords: Hip fracture; Mortality; Neutrophil-to-lymphocyte ratio.