title: 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.
authors.affiliation: Department of Anesthesiology, Post-Anesthetic Outcome Unit, Institute of Neuroscience (Pôle CEMO), Université catholique de Louvain, Av. Hippocrate 10, 1200 Brussels, Belgium. Electronic address: forgetpatrice@yahoo.fr.
authors.forename: Patrice
authors.initials: P
authors.lastname: Forget
authors.affiliation: Department of Anesthesiology, Post-Anesthetic Outcome Unit, Institute of Neuroscience (Pôle CEMO), Université catholique de Louvain, Av. Hippocrate 10, 1200 Brussels, Belgium.
authors.forename: Nicolas
authors.initials: N
authors.lastname: Moreau
authors.affiliation: Department of Anesthesiology, Post-Anesthetic Outcome Unit, Institute of Neuroscience (Pôle CEMO), Université catholique de Louvain, Av. Hippocrate 10, 1200 Brussels, Belgium.
authors.forename: Harald
authors.initials: H
authors.lastname: Engel
authors.affiliation: Department of Orthopaedic and Traumatology Surgery, Cliniques universitaires Saint-Luc, Université catholique de Louvain, Av. Hippocrate 10, 1200 Brussels, Belgium.
authors.forename: Olivier
authors.initials: O
authors.lastname: Cornu
authors.affiliation: Department of Geriatric Medicine, Cliniques universitaires Saint-Luc, Université catholique de Louvain, Av. Hippocrate 10, 1200 Brussels, Belgium.
authors.forename: Benoît
authors.initials: B
authors.lastname: Boland
authors.affiliation: Department of Anesthesiology, Post-Anesthetic Outcome Unit, Institute of Neuroscience (Pôle CEMO), Université catholique de Louvain, Av. Hippocrate 10, 1200 Brussels, Belgium.
authors.forename: Marc
authors.initials: M
authors.lastname: De Kock
authors.affiliation: Department of Internal and Perioperative Medicine, Cliniques universitaires Saint-Luc, Université catholique de Louvain, Av. Hippocrate 10, 1200 Brussels, Belgium.
authors.forename: Jean-Cyr
authors.initials: JC
authors.lastname: Yombi
mesh_terms: D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D001530:Belgium / Q000453:epidemiology; D005260:Female; D006620:Hip Fractures / Q000097:blood / Q000401:mortality* / Q000601:surgery*; D006801:Humans; D007958:Leukocyte Count; D008297:Male; D015999:Multivariate Analysis; D009504:Neutrophils / Q000378:metabolism*; D011184:Postoperative Period; D012189:Retrospective Studies; D012307:Risk Factors; D012737:Sex Factors
keywords: Hip fracture; Mortality; Neutrophil-to-lymphocyte ratio