Summary: A procedure for creating a simplified version of fracture risk assessment tool (FRAX ®) is described. Calibration, fracture prediction, and concordance were compared with the full FRAX tool using two large, complementary Canadian datasets. Introduction: The Canadian Association of Radiologists and Osteoporosis Canada (CAROC) system for fracture risk assessment is based upon sex, age, bone mineral density (BMD), prior fragility fracture, and glucocorticoid use. CAROC does not require computer or web access, and categorizes 10-year major osteoporotic fracture risk as low (<10%), moderate (10-20%), or high (>20%). Methods Basal CAROC fracture risk tables (by age, sex, and femoral neck BMD) were constructed from Canadian FRAX probabilities for major osteoporotic fractures (adjusted for prevalent clinical risk factors). We assessed categorization and fracture prediction with the updated CAROC system in the CaMos and Manitoba BMD cohorts. Results The new CAROC system demonstrated high concordance with the Canadian FRAX tool for risk category in both the CaMos and Manitoba cohorts (89% and 88%). Ten-year fracture outcomes in CaMos and Manitoba BMD cohorts showed good discrimination and calibration for both CAROC (6.1-6.5% in low-risk, 13.5-14.6% in moderate-risk, and 22.3-29.1% in high-risk individuals) and FRAX (6.1-6.6% in low-risk, 14.4-16.1% in moderate-risk, and 23.4-31.0% in high-risk individuals). Reclassification from the CAROC risk category to a different risk category under FRAX occurred in <5% for low-risk, 20-24% for moderate-risk, and 27-30% for highrisk individuals. Reclassified individuals had 10-year fracture outcomes that were still within or close to the original nominal-risk range.. Conclusion: The new CAROC system is well calibrated to the Canadian population and shows a high degree of concordance with the Canadian FRAX tool. The CAROC system provides s a simple alternative when it is not feasible to use the full Canadian FRAX tool.
Bibliographical noteFunding Information:
The Canadian Multicentre Osteoporosis Study was funded by the Canadian Institutes of Health Research (CIHR), Merck Frosst Canada Ltd., Eli Lilly Canada Inc., Novartis Pharmaceuticals Inc., The Alliance for Better Bone Health: Sanofi-Aventis, Procter & Gamble Pharmaceuticals Canada Inc., Amgen, The Dairy Farmers of Canada and The Arthritis Society.
William Leslie is part of a speaker bureau for Merck Frosst and Amgen. He has also received unrestricted educational and/or research grants from Amgen; Merck Frosst; sanofi-Aventis; Procter & Gamble; Genzyme and is a member of the following advisory boards: Genzyme; Novartis; and Amgen. Lisa Lix received an unrestricted research grant from Amgen. In the past 3 years, Eugene McCloskey has received speaker fees and/or unrestricted research grants from Novartis, Amgen, AstraZeneca, Pfizer, Bayer, Procter & Gamble, Lilly, Roche, Servier, and Hologic.
- Bone mineral density
- Fracture risk prediction