title: Low Levels of Hemoglobin at Admission Are Associated With Increased 30-Day Mortality in Patients With Hip Fracture.
abstract: BACKGROUND
  Previous smaller studies suggest that anemia is a risk factor for mortality in patients with hip fracture. The purpose of this investigation was to assess the correlation between hemoglobin at admission with 30-day mortality following a hip fracture in a large-scale study.
  
  
  METHODS
  From January 1996 to December 2012, all patients with hip fracture (>60 years of age) admitted to Bispebjerg Hospital, Copenhagen, were identified from a local hip fracture database. We excluded conservatively treated patients and patients who died preoperatively.
  
  
  RESULTS
  Seven thousand four hundred twenty-one consecutive patients with hip fracture were identified. Of those 7319 had a hemoglobin measurement on admission and were thus eligible for further analysis. Mean hemoglobin for patients alive at 30 days was 7.6 (standard deviation [SD]: 1.0) and for deceased patients 7.4 (SD: 1.1), P < .0001. Mean age was 82.6 years (SD: 8.5), and 76.5% of the population were female (Nfemales = 5600). The 30-day mortality decreases for every increase in hemoglobin of 1.0 mmol/L in a univariate analysis (P < .0001). The hazard ratio (HR) with 95% confidence interval (CI) for 30-day mortality in patients with anemia (<7.3 mmol/L for females and <8.3 mmol/L for males; Nanemic = 3235) was 1.66 (CI: 1.43-1.91, P < .0001). Adjusting for age, type of fracture, gender, and comorbidities (Charlson score) slightly attenuated the risk estimate (HR: 1.21, CI: 1.03-1.41, P = .02).
  
  
  CONCLUSIONS
  This study demonstrates increased 30-day mortality in patients with low hemoglobin at admission, even after adjusting for comorbidities.
authors.affiliation: Department of Orthopaedic Surgery, Bispebjerg Hospital, University of Copenhagen, Copenhagen, Denmark.
authors.forename: Katrine
authors.initials: K
authors.lastname: Praetorius
authors.affiliation: Department of Orthopaedic Surgery, Bispebjerg Hospital, University of Copenhagen, Copenhagen, Denmark.
authors.forename: Christian M
authors.initials: CM
authors.lastname: Madsen
authors.affiliation: OPEN-Odense Patient Data Explorative Network, Institute of Clinical Research, University of Southern Denmark, Odense, Denmark.
authors.forename: Bo
authors.initials: B
authors.lastname: Abrahamsen
authors.affiliation: Department of Clinical Biochemistry, Bispebjerg Hospital, University of Copenhagen, Copenhagen, Denmark.
authors.forename: Henrik L
authors.initials: HL
authors.lastname: Jørgensen
authors.affiliation: Department of Orthopaedic Surgery, Bispebjerg Hospital, University of Copenhagen, Copenhagen, Denmark.
authors.forename: Jes B
authors.initials: JB
authors.lastname: Lauritzen
authors.affiliation: Department of Orthopaedic Surgery, Bispebjerg Hospital, University of Copenhagen, Copenhagen, Denmark.
authors.forename: Anne Sofie B
authors.initials: AS
authors.lastname: Laulund
keywords: anemia; hemoglobin; hip fractures; mortality