title: External validation of the Garvan nomograms for predicting absolute fracture risk: the Tromsø study.
abstract: BACKGROUND
  Absolute risk estimation is a preferred approach for assessing fracture risk and treatment decision making. This study aimed to evaluate and validate the predictive performance of the Garvan Fracture Risk Calculator in a Norwegian cohort.
  
  
  METHODS
  The analysis included 1637 women and 1355 aged 60+ years from the Tromsø study. All incident fragility fractures between 2001 and 2009 were registered. The predicted probabilities of non-vertebral osteoporotic and hip fractures were determined using models with and without BMD. The discrimination and calibration of the models were assessed. Reclassification analysis was used to compare the models performance.
  
  
  RESULTS
  The incidence of osteoporotic and hip fracture was 31.5 and 8.6 per 1000 population in women, respectively; in men the corresponding incidence was 12.2 and 5.1. The predicted 5-year and 10-year probability of fractures was consistently higher in the fracture group than the non-fracture group for all models. The 10-year predicted probabilities of hip fracture in those with fracture was 2.8 (women) to 3.1 times (men) higher than those without fracture. There was a close agreement between predicted and observed risk in both sexes and up to the fifth quintile. Among those in the highest quintile of risk, the models over-estimated the risk of fracture. Models with BMD performed better than models with body weight in correct classification of risk in individuals with and without fracture. The overall net decrease in reclassification of the model with weight compared to the model with BMD was 10.6% (p = 0.008) in women and 17.2% (p = 0.001) in men for osteoporotic fractures, and 13.3% (p = 0.07) in women and 17.5% (p = 0.09) in men for hip fracture.
  
  
  CONCLUSIONS
  The Garvan Fracture Risk Calculator is valid and clinically useful in identifying individuals at high risk of fracture. The models with BMD performed better than those with body weight in fracture risk prediction.
authors.affiliation: Department of Health and Care Sciences, Faculty of Health Sciences, UiT - The Arctic University of Norway, Tromsø, Norway.
authors.forename: Luai A
authors.initials: LA
authors.lastname: Ahmed
authors.affiliation: Osteoporosis & Bone Biology Program, Garvan Institute of Medical Research, Sydney, Australia.
authors.forename: Nguyen D
authors.initials: ND
authors.lastname: Nguyen
authors.affiliation: Department of Health and Care Sciences, Faculty of Health Sciences, UiT - The Arctic University of Norway, Tromsø, Norway.
authors.forename: Åshild
authors.initials: Å
authors.lastname: Bjørnerem
authors.affiliation: Department of Clinical Medicine, Faculty of Health Sciences, UiT - The Arctic University of Norway, Tromsø, Norway; Medical Clinic, University Hospital of Northern Norway, Tromsø, Norway.
authors.forename: Ragnar M
authors.initials: RM
authors.lastname: Joakimsen
authors.affiliation: Department of Health and Care Sciences, Faculty of Health Sciences, UiT - The Arctic University of Norway, Tromsø, Norway.
authors.forename: Lone
authors.initials: L
authors.lastname: Jørgensen
authors.affiliation: Department of Radiology, University Hospital of Northern Norway, Tromsø, Norway.
authors.forename: Jan
authors.initials: J
authors.lastname: Størmer
authors.affiliation: Osteoporosis & Bone Biology Program, Garvan Institute of Medical Research, Sydney, Australia.
authors.forename: Dana
authors.initials: D
authors.lastname: Bliuc
authors.affiliation: Osteoporosis & Bone Biology Program, Garvan Institute of Medical Research, Sydney, Australia; Department of Endocrinology, St Vincent's Hospital, Sydney, Australia; St. Vincent's Clinical School, UNSW Australia, Sydney, Australia.
authors.forename: Jacqueline R
authors.initials: JR
authors.lastname: Center
authors.affiliation: Osteoporosis & Bone Biology Program, Garvan Institute of Medical Research, Sydney, Australia; Department of Endocrinology, St Vincent's Hospital, Sydney, Australia; School of Medicine Sydney, University of Notre Dame Australia, Sydney, Australia; St. Vincent's Clinical School, UNSW Australia, Sydney, Australia.
authors.forename: John A
authors.initials: JA
authors.lastname: Eisman
authors.affiliation: Osteoporosis & Bone Biology Program, Garvan Institute of Medical Research, Sydney, Australia; St. Vincent's Clinical School, UNSW Australia, Sydney, Australia; School of Public Health and Community Medicine, University of New South Wales, Sydney, Australia; Centre for Health Technologies, University of Technology, Sydney, Australia.
authors.forename: Tuan V
authors.initials: TV
authors.lastname: Nguyen
authors.affiliation: Department of Health and Care Sciences, Faculty of Health Sciences, UiT - The Arctic University of Norway, Tromsø, Norway.
authors.forename: Nina
authors.initials: N
authors.lastname: Emaus
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015331:Cohort Studies; D005260:Female; D050723:Fractures, Bone / Q000175:diagnosis* / Q000453:epidemiology; D006620:Hip Fractures / Q000175:diagnosis / Q000453:epidemiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D049451:Nomograms; D009664:Norway / Q000453:epidemiology; D058866:Osteoporotic Fractures / Q000175:diagnosis / Q000453:epidemiology; D012372:ROC Curve; D018570:Risk Assessment / Q000379:methods*