Independent external validation of nomograms for predicting risk of low-trauma fracture and hip fracture
Lisa Langsetmo, Tuan V Nguyen, Nguyen D Nguyen
Christopher S Kovacs, Jerilynn C Prior, David A Hanley, Jacqueline R Center, John A Eisman, Jonathan D Adachi, Robert G Josse, S. Morin , Canadian Multicentre Osteoporosis Study Research Group , the Canadian Multicentre Osteoporosis Study Research Group
A set of nomograms based on the Dubbo Osteoporosis Epidemiology Study predicts the fiveand ten-year absolute risk of fracture using age, bone mineral density and history of falls and low-trauma fracture. We assessed the discrimination and calibration of these nomograms among participants in the Canadian Multicentre Osteoporosis Study.
Methods
We included participants aged 55-95 years for whom bone mineral density measurement data and at least one year of follow-up data were available. Self-reported incident fractures were identified by yearly postal questionnaire or interview (years 3, 5 and 10). We included low-trauma fractures before year 10, except those of the skull, face, hands, ankles and feet. We used a Cox proportional hazards model.
Results
Among 4152 women, there were 583 fractures, with a mean follow-up time of 8.6 years. Among 1606 men, there were 116 fractures, with a mean follow-up time of 8.3 years. Increasing age, lower bone mineral density, prior fracture and prior falls were associated with increased risk of fracture. For low-trauma fractures, the concordance between predicted risk and fracture events (Harrell C) was 0.69 among women and 0.70 among men. For hip fractures, the concordance was 0.80 among women and 0.85 among men. The observed fracture risk was similar to the predicted risk in all quintiles of risk except the highest quintile of women, where it was lower. The net reclassification index (19.2%, 95% confidence interval [CI] 6.3% to 32.2%), favours the Dubbo nomogram over the current Canadian guidelines for men.
Interpretation
The published nomograms provide good fracture-risk discrimination in a representative sample of the Canadian population.
fracture risk nomogram validation, low-trauma fracture prediction, bone density nomogram external validation, clinical risk factors fracture prediction, osteoporosis prediction model, fracture risk calculator validation, bone mineral density fracture model, independent fracture risk tool, clinical fracture prediction accuracy, osteoporosis screening model
PMID 21173069 21173069 DOI 10.1503/cmaj.100458 10.1503/cmaj.100458
Cite this article
Langsetmo, L., Nguyen, T. V., Nguyen, N. D., Kovacs, C. S., Prior, J. C., Center, J. R., Morin, S., Josse, R. G., Adachi, J. D., Hanley, D. A., Eisman, J. A., & Canadian Multicentre Osteoporosis Study Research Group (2011). Independent external validation of nomograms for predicting risk of low-trauma fracture and hip fracture. CMAJ : Canadian Medical Association journal = journal de l'Association medicale canadienne, 183(2), E107-E114. https://doi.org/10.1503/cmaj.100458
Langsetmo L, Nguyen TV, Nguyen ND, Kovacs CS, Prior JC, Center JR, et al. Independent external validation of nomograms for predicting risk of low-trauma fracture and hip fracture. CMAJ. 2011;183(2):E107-E114. doi:10.1503/cmaj.100458
Langsetmo, L., et al. "Independent external validation of nomograms for predicting risk of low-trauma fracture and hip fracture." CMAJ : Canadian Medical Association journal = journal de l'Association medicale canadienne, vol. 183, no. 2, 2011, pp. E107-E114.
Fractures have largely been assessed by their impact on quality of life or health care costs. We conducted this study to evaluate the relation between fractures and mortality. A total of 7753 randomly selected people (2187 men and 5566 women) aged 50 years and older from across Canada participated in a 5-year observational cohort study. Incident fractures were identified on the basis of validated self-report and were classified by type (vertebral, pelvic, forearm or wrist, rib, hip and "other"). We subdivided fracture groups by the year in which the fracture occurred during follow-up; those occurring in the fourth and fifth years were grouped together. We examined the relation between the time of the incident fracture and death. Compared with participants who had no fracture during follow-up, those who had a vertebral fracture in the second year were at increased risk of death (adjusted hazard ratio [HR] 2.7, 95% confidence interval [CI] 1.1-6.6); also at risk were those who had a hip fracture during the first year (adjusted HR 3.2, 95% CI 1.4-7.4). Among women, the risk of death was increased for those with a vertebral fracture during the first year (adjusted HR 3.7, 95% CI 1.1-12.8) or the second year of follow-up (adjusted HR 3.2, 95% CI 1.2-8.1). The risk of death was also increased among women with hip fracture during the first year of follow-up (adjusted HR 3.0, 95% CI 1.0-8.7). Vertebral and hip fractures are associated with an increased risk of death. Interventions that reduce the incidence of these fractures need to be implemented to improve survival.
To revise and expand the 1996 Osteoporosis Society of Canada clinical practice guidelines for the management of osteoporosis, incorporating recent advances in diagnosis, prevention and management of osteoporosis, and to identify and assess the evidence supporting the recommendations. All aspects of osteoporosis care and its fracture complications - including classification, diagnosis, management and methods for screening, as well as prevention and reducing fracture risk - were reviewed, revised as required and expressed as a set of recommendations. Strategies for identifying and evaluating those at high risk; the use of bone mineral density and biochemical markers in diagnosis and assessing response to management; recommendations regarding nutrition and physical activity; and the selection of pharmacologic therapy for the prevention and management of osteoporosis in men and women and for osteoporosis resulting from glucocorticoid treatment. All recommendations were developed using a justifiable and reproducible process involving an explicit method for the evaluation and citation of supporting evidence. All recommendations were reviewed by members of the Scientific Advisory Council of the Osteoporosis Society of Canada, an expert steering committee and others, including family physicians, dietitians, therapists and representatives of various medical specialties involved in osteoporosis care (geriatric medicine, rheumatology, endocrinology, obstetrics and gynecology, nephrology, radiology) as well as methodologists from across Canada. BENEFITS, Earlier diagnosis and prevention of fractures should decrease the medical, social and economic burdens of this disease. This document outlines detailed recommendations pertaining to all aspects of osteoporosis. Strategies for identifying those at increased risk (i.e., those with at least one major or 2 minor risk factors) and screening with central dual-energy x-ray absorptiometry at age 65 years are recommended. Bisphosphonates and raloxifene are first-line therapies in the prevention and treatment of postmenopausal osteoporosis. Estrogen and progestin/progesterone is a first-line therapy in the prevention and a second-line therapy in the treatment of postmenopausal osteoporosis. Nasal calcitonin is a second-line therapy in the treatment of postmenopausal osteoporosis. Although not yet approved for use in Canada, hPTH(1-34) is expected to be a first-line treatment for postmenopausal women with severe osteoporosis. Ipriflavone, vitamin K and fluoride are not recommended. Bisphosphonates are the first-line therapy for the prevention and treatment of osteoporosis in patients requiring prolonged glucocorticoid therapy and for men with osteoporosis. Nasal or parenteral calcitonin is a first-line treatment for pain associated with acute vertebral fractures. Impact-type exercise and age-appropriate calcium and vitamin D intake are recommended for the prevention of osteoporosis. All recommendations were graded according to the strength of the evidence; where the evidence was insufficient and recommendations were based on consensus opinion alone, this is indicated. These guidelines are viewed as a work in progress and will be updated periodically in response to advances in this field.
Bone HealthDiagnosticsPerimenopause/Menopause
Open Access
Most premenopausal women with low trauma fracture(s) or low bone mineral density have a secondary cause of osteoporosis or bone loss. Where possible, treatment of the underlying cause should be the focus of management. Premenopausal women with an ongoing cause of bone loss and those who have had, or continue to have, low trauma fractures may require pharmacologic intervention. Clinical trials provide evidence of benefits of bisphosphonates and teriparatide for bone mineral density in several types of premenopausal osteoporosis, but studies are small and do not provide evidence regarding fracture risk reduction.