title: WHO absolute fracture risk models (FRAX): do clinical risk factors improve fracture prediction in older women without osteoporosis?
abstract: Bone mineral density (BMD) is a strong predictor of fracture, yet most fractures occur in women without osteoporosis by BMD criteria. To improve fracture risk prediction, the World Health Organization recently developed a country-specific fracture risk index of clinical risk factors (FRAX) that estimates 10-year probabilities of hip and major osteoporotic fracture. Within differing baseline BMD categories, we evaluated 6252 women aged 65 or older in the Study of Osteoporotic Fractures using FRAX 10-year probabilities of hip and major osteoporotic fracture (ie, hip, clinical spine, wrist, and humerus) compared with incidence of fractures over 10 years of follow-up. Overall ability of FRAX to predict fracture risk based on initial BMD T-score categories (normal, low bone mass, and osteoporosis) was evaluated with receiver-operating-characteristic (ROC) analyses using area under the curve (AUC). Over 10 years of follow-up, 368 women incurred a hip fracture, and 1011 a major osteoporotic fracture. Women with low bone mass represented the majority (n = 3791, 61%); they developed many hip (n = 176, 48%) and major osteoporotic fractures (n = 569, 56%). Among women with normal and low bone mass, FRAX (including BMD) was an overall better predictor of hip fracture risk (AUC = 0.78 and 0.70, respectively) than major osteoporotic fractures (AUC = 0.64 and 0.62). Simpler models (eg, age + prior fracture) had similar AUCs to FRAX, including among women for whom primary prevention is sought (no prior fracture or osteoporosis by BMD). The FRAX and simpler models predict 10-year risk of incident hip and major osteoporotic fractures in older US women with normal or low bone mass.
authors.affiliation: Center for Health Research, Kaiser Permanente Northwest/Hawaii, Portland, OR 97227, USA. teresa.hillier@kpchr.org
authors.forename: Teresa A
authors.initials: TA
authors.lastname: Hillier
authors.forename: Jane A
authors.initials: JA
authors.lastname: Cauley
authors.forename: Joanne H
authors.initials: JH
authors.lastname: Rizzo
authors.forename: Kathryn L
authors.initials: KL
authors.lastname: Pedula
authors.forename: Kristine E
authors.initials: KE
authors.lastname: Ensrud
authors.forename: Douglas C
authors.initials: DC
authors.lastname: Bauer
authors.forename: Li-Yung
authors.initials: LY
authors.lastname: Lui
authors.forename: Kimberly K
authors.initials: KK
authors.lastname: Vesco
authors.forename: Dennis M
authors.initials: DM
authors.lastname: Black
authors.forename: Meghan G
authors.initials: MG
authors.lastname: Donaldson
authors.forename: Erin S
authors.initials: ES
authors.lastname: Leblanc
authors.forename: Steven R
authors.initials: SR
authors.lastname: Cummings
mesh_terms: D015519:Bone Density / Q000502:physiology; D001842:Bone and Bones / Q000473:pathology / Q000503:physiopathology; D015331:Cohort Studies; D005260:Female; D005500:Follow-Up Studies; D050723:Fractures, Bone / Q000175:diagnosis* / Q000453:epidemiology* / Q000503:physiopathology / Q000628:therapy; D006801:Humans; D008954:Models, Biological; D009929:Organ Size; D010024:Osteoporosis / Q000150:complications*; D011379:Prognosis; D012307:Risk Factors; D014944:World Health Organization