title: Independent external validation of nomograms for predicting risk of low-trauma fracture and hip fracture.
abstract: BACKGROUND
  A set of nomograms based on the Dubbo Osteoporosis Epidemiology Study predicts the five- and ten-year absolute risk of fracture using age, bone mineral density and history of falls and low-trauma fracture. We assessed the discrimination and calibration of these nomograms among participants in the Canadian Multicentre Osteoporosis Study.
  
  
  METHODS
  We included participants aged 55-95 years for whom bone mineral density measurement data and at least one year of follow-up data were available. Self-reported incident fractures were identified by yearly postal questionnaire or interview (years 3, 5 and 10). We included low-trauma fractures before year 10, except those of the skull, face, hands, ankles and feet. We used a Cox proportional hazards model.
  
  
  RESULTS
  Among 4152 women, there were 583 fractures, with a mean follow-up time of 8.6 years. Among 1606 men, there were 116 fractures, with a mean follow-up time of 8.3 years. Increasing age, lower bone mineral density, prior fracture and prior falls were associated with increased risk of fracture. For low-trauma fractures, the concordance between predicted risk and fracture events (Harrell C) was 0.69 among women and 0.70 among men. For hip fractures, the concordance was 0.80 among women and 0.85 among men. The observed fracture risk was similar to the predicted risk in all quintiles of risk except the highest quintile of women, where it was lower. The net reclassification index (19.2%, 95% confidence interval [CI] 6.3% to 32.2%), favours the Dubbo nomogram over the current Canadian guidelines for men.
  
  
  CONCLUSIONS
  The published nomograms provide good fracture-risk discrimination in a representative sample of the Canadian population.
authors.affiliation: CaMos National Coordinating Centre, McGill University, Montréal, Que., Canada.
authors.forename: Lisa
authors.initials: L
authors.lastname: Langsetmo
authors.forename: Tuan V
authors.initials: TV
authors.lastname: Nguyen
authors.forename: Nguyen D
authors.initials: ND
authors.lastname: Nguyen
authors.forename: Christopher S
authors.initials: CS
authors.lastname: Kovacs
authors.forename: Jerilynn C
authors.initials: JC
authors.lastname: Prior
authors.forename: Jacqueline R
authors.initials: JR
authors.lastname: Center
authors.forename: Suzanne
authors.initials: S
authors.lastname: Morin
authors.forename: Robert G
authors.initials: RG
authors.lastname: Josse
authors.forename: Jonathan D
authors.initials: JD
authors.lastname: Adachi
authors.forename: David A
authors.initials: DA
authors.lastname: Hanley
authors.forename: John A
authors.initials: JA
authors.lastname: Eisman
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D002170:Canada / Q000453:epidemiology; D005260:Female; D005598:Fractures, Spontaneous / Q000453:epidemiology / Q000517:prevention & control*; D006620:Hip Fractures / Q000453:epidemiology / Q000517:prevention & control*; D006801:Humans; D008297:Male; D008875:Middle Aged; D049451:Nomograms; D010024:Osteoporosis / Q000145:classification / Q000175:diagnosis*; D016016:Proportional Hazards Models; D012016:Reference Values; D015203:Reproducibility of Results; D018570:Risk Assessment