Simplified system for absolute fracture risk assessment: Clinical validation in Canadian women

Abstract

Absolute 10-yr fracture risk based on multiple factors is the preferred method for risk assessment. A simplified risk assessment system from sex, age, DXA, and two clinical risk factors (CRFs) - prior fracture and systemic corticosteroid (CS) use - has been used in Canada since 2005. This study was undertaken to evaluate this system in the Canadian female population. A total of 16,205 women >50 yr of age at the time of baseline BMD (1998-2002) were identified in a database containing all clinical DXA test results for the Province of Manitoba, Canada. Basal 10-yr fracture risk from age and minimum T-score (lumbar spine, femur neck, trochanter, total hip) was categorized as low (<10%), moderate (10-20%), or high (>20%). Health service records since 1987 were assessed for prior fracture codes (N = 5224), recent major CS use (N = 616), and fracture codes after BMD testing (mean, 3.1 yr of follow-up) for the hip, vertebrae, forearm, or humerus (designated osteoporotic, N = 757). Fracture risk predicted from age and minimum T-score alone showed a significant gradient in observed fracture rates (low 5.1 [95% CI, 4.1-6.4], moderate 11.5 [95% CI, 10.1-13.0], high 25.4 [95% CI, 23.2-27.9] per 1000 person-years; p-for-trend <0.0001). There was an incremental increase in incident fracture rates from a prior fracture (13.9 [95% CI, 11.3-16.4] per 1000 person-years) or major CS use (11.2 [95% CI, 4.1-18.2] per 1000 person-years). This simplified fracture risk assessment system provides an assessment of fracture risk that is consistent with observed fracture rates. © 2009 American Society for Bone and Mineral Research.