title: Effects of FRAX(®) model calibration on intervention rates: a simulation study.
abstract: The WHO fracture risk assessment tool (FRAX(®)) estimates an individual's 10-yr major osteoporotic and hip fracture probabilities using a tool customized to the fracture epidemiology of a specific population. Incorrect model calibration could therefore affect performance of the model in clinical practice. The current analysis was undertaken to explore how simulated miscalibration in the FRAX(®) tool would affect the numbers of individuals meeting specific intervention criteria (10-yr major osteoporotic fracture probability ≥20%, 10-yr hip fracture probability ≥3%). The study cohort included 36,730 women and 2873 men aged 50yr and older with FRAX(®) probability estimates using femoral neck bone mineral density. We simulated relative miscalibration error in 10% increments from -50% to +50% relative to a correctly calibrated FRAX(®) model. We found that small changes in model calibration (even on the order of 10%) had large effects on the number of individuals qualifying for treatment. There was a steep gradient in the relationship between relative change in calibration and relative change in intervention rates: for every 1% change in calibration, there was a 2.5% change in intervention rates for women and 4.1% for men. For hip fracture probability, the gradient of the relationship was closer to unity. These results highlight the importance of FRAX(®) model calibration, and speak to the importance of using high-quality fracture epidemiology in constructing FRAX(®) tools.
authors: Department of Medicine, University of Manitoba, Winnipeg, Canada. bleslie@sbgh.mb.ca
authors: William D
authors: WD
authors: Leslie
authors: Lisa M
authors: LM
authors: Lix
mesh_terms: D015502:Absorptiometry, Photon; D000368:Aged; D015519:Bone Density; D002138:Calibration; D003936:Diagnosis, Computer-Assisted; D005260:Female; D005272:Femur Neck / Q000000981:diagnostic imaging / Q000473:pathology; D006620:Hip Fractures / Q000175:diagnosis*; D006801:Humans; D008297:Male; D008875:Middle Aged; D015233:Models, Statistical; D010024:Osteoporosis / Q000188:drug therapy; D058866:Osteoporotic Fractures / Q000175:diagnosis* / Q000517:prevention & control; D018570:Risk Assessment