Fracture prediction from FRAX for Canadian ethnic groups:​ a registry-based cohort study

Leslie, W. D.; Morin, S. N.; Lix, L. M.; McCloskey, E. V.; Johansson, H.; Harvey, N. C.; Kanis, J. A.

Affiliations

¹University of Manitoba, Winnipeg, Canada

²McGill University, Montreal, Canada

³Centre for Metabolic Bone Diseases, University of Sheffield Medical School, Sheffield, UK

⁴Mary McKillop Institute for Health Research, Australian Catholic University, Melbourne, Fitzroy, VIC 3065, Australia

⁵MRC Lifecourse Epidemiology Unit, University of Southampton, Southampton, UK

⁶NIHR Southampton Biomedical Research Centre, University of Southampton and University Hospital Southampton NHS Foundation Trust, Southampton, UK

Abstract and keywords

Summary: We identified large between-ethnicity calibration differences in the Canadian FRAX® tool which substantially overestimated the major osteoporotic fracture (MOF) risk in Asian women and Black women, and overestimated hip fracture risk in Asian women.

Purpose: FRAX® is calibrated using population-specific fracture and mortality data. The need for FRAX to accommodate ethnic diversity within a country is uncertain. We addressed this question using the population-based Manitoba Bone Mineral Density (BMD) Program registry and self-reported ethnicity.

Methods: The study population was women aged 40 years or older with baseline FRAX assessments (Canadian and other ethnic calculators), fracture outcomes, and self-reported ethnicity (White N = 68,907 [referent], Asian N = 1910, Black N = 356). Adjusted hazard ratios (HR) with 95% confidence intervals (CI) for time to MOF and hip fracture were estimated. We examined candidate variables from DXA that might contribute to ethnic differences including skeletal size, hip axis length (HAL), trabecular bone score (TBS), and estimated body composition.

Results: Adjusted for baseline risk using the Canadian FRAX tool with BMD, Asian women compared with White women were at much lower risk for MOF (HR 0.46, 95% CI 0.35–0.59) and hip fracture (0.16, 95% CI 0.08–0.34). Black women were also at lower MOF risk (HR 0.58, 95% CI 0.32–1.00); there were no hip fractures. The US ethnic-specific FRAX calculators accounted for most of the between-ethnicity differences in MOF risk (86% for Asian, 92% for Black) but only partially accounted for lower hip fracture risk in Asian women (40%). The candidate variables explained only a minority of the effect of ethnicity. Gradient of risk in analyses was similar (p-interactions ethnicity*FRAX non-significant).

Conclusions: We identified significant ethnic differences in performance of the Canadian FRAX tool with fracture probability overestimated among Asian and Black women. The US ethnic calculators helped to address this discrepancy for MOF risk assessment, but not for hip fracture risk among Asian women.

Keywords: Dual-energy x-ray absorptiometry; ethnicity; fractures; FRAX; osteoporosis

Links

DOI: 10.1007/s00198-020-05594-8

PubMed: 32809043

WoS: 000561935600001

History

Received: 2020-04-12

Accepted: 2020-07-07

Online: 2020-08-18

Cited Works (7)

Year	Entry
2009	Kanis JA, Oden A, Johansson H, Borgström F, Ström O, McCloskey E. FRAX^® and its applications to clinical practice. Bone. May 2009;44(5):734-743.
1998	Looker AC, Wahner HW, Dunn WL, Calvo MS, Harris TB, Heyse SP, Johnston CC Jr, Lindsay R. Updated data on proximal femur bone mineral levels of US adults. Osteoporos Int. 1998;8(5):468-489.
2012	Kanis JA, Odén A, McCloskey EV, Johansson H, Wahl DA, Cooper C; IOF Working Group on Epidemiology and Quality of Life. A systematic review of hip fracture incidence and probability of fracture worldwide. Osteoporos Int. September 2012;23(9):2239-2256.
2005	Leslie WD, Caetano PA, MacWilliam LR, Finlayson GS. Construction and validation of a population-based bone densitometry database. J Clin Densitom. Spring, 2005;8(1):25-30.
2016	Kanis JA, Harvey NC, Cooper C, Johansson H, Odén A, McCloskey EV; The Advisory Board of the National Osteoporosis Guideline Group. A systematic review of intervention thresholds based on FRAX: a report prepared for the National Osteoporosis Guideline Group and the International Osteoporosis Foundation. Arch Osteoporos. December 2016;11(1):25.
2011	Hans D, Goertzen AL, Krieg M-A, Leslie WD. Bone microarchitecture assessed by TBS predicts osteoporotic fractures independent of bone density: the Manitoba study. J Bone Miner Res. November 2011;26(11):2762-2769.
2010	Leslie WD, Lix LM, Johansson H, Oden A, McCloskey E, Kanis JA; Manitoba Bone Density Program. Independent clinical validation of a Canadian FRAX tool: fracture prediction and model calibration. J Bone Miner Res. November 2010;25(11):2350-2358.