Prevention and management of osteoporosis: consensus statements from the Scientific Advisory Board of the Osteoporosis Society of Canada. 2. The use of bone density measurement in the diagnosis and management of osteoporosis.

OBJECTIVE: To determine the best method of diagnosing osteoporosis and determining fracture risk and to promote standards in the use of bone densitometry and the reporting of results. OPTIONS: Methods of bone mineral density measurement: dual-energy x-ray absorptiometry (DXA), radiographic absorptiometry, single-photon absorptiometry, dual-photon absorptiometry, quantitative computed tomography, quantitative ultrasound, neutron activation analysis. The options of using bone densitometry in individual patient management and as a mass screening tool are also considered. OUTCOMES: Appropriate use of densitometry to promote accurate diagnosis and assessment of fracture risk and timely, appropriate treatment. EVIDENCE: Relevant clinical studies and reports were examined. Clinical practice in Canada was also considered. VALUES: Accurate assessment of osteoporotic fracture risk and diagnosis of osteoporosis and assuring low exposure to medical radiation were given a high value. BENEFITS, HARMS AND COSTS: Early diagnosis through bone density measurement allows proper management of osteoporosis to minimize injury and disability, improve quality of life and reduce the personal and social costs associated with the condition. Potential harms include radiation exposure and cost. The harms and costs of appropriate use of DXA are minimal compared with the harms and costs associated with osteoporosis. RECOMMENDATIONS: Bone mineral density should be measured only to assist in making a clinical management choice. DXA is the best method of measuring bone density and, thus, the best available indicator of osteoporotic fracture risk. Plain radiographs may supplement DXA if there is a specific reason for their use. Measurement of the lumbar spine and femoral neck is standard, but a different site or a single measurement is recommended in specific cases. Unless accelerated bone loss is suspected, DXA should be repeated every 2 to 4 years for patients receiving ovarian hormone therapy and 1 to 2 years for patients undergoing bisphosphonate therapy. Measurements and reporting of results must be standardized. Reports should refer to the World Health Organization's recommended definitions of osteopenia and osteoporosis and provide actual measurement and its relation to peak bone mass.