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 m ineral density measurement: dual-energy x-ray absorptiometry (DXA), ra diographic absorptiometry, single-photon absorptiometry, dual-photon a bsorptiometry, quantitative computed tomography, quantitative ultrasou nd, neutron activation analysis. The options of using bone densitometr y in individual patient management and as a mass screening tool are al so considered.Outcomes: Appropriate use of densitometry to promote acc urate diagnosis and assessment of fracture risk and timely, appropriat e treatment. Evidence: Relevant clinical studies and reports were exam ined. Clinical practice in Canada was also considered. Values: Accurat e assessment of osteoporotic fracture risk and diagnosis of osteoporos is and assuring low exposure to medical radiation were given a high va lue. Benefits, harms and costs: Early diagnosis through bone density m easurement allows proper management of osteoporosis to minimize injury and disability, improve quality of life and reduce the personal and s ocial costs associated with the condition. Potential harms include rad iation exposure and cost. The harms and costs of appropriate use of DX A are minimal compared with the harms and costs associated with osteop orosis. Recommendations: Bone mineral density should be measured only to assist in making a clinical management choice. DXA is the best meth od of measuring bone density and, thus, the best available indicator o f osteoporotic fracture risk. Plain radiographs may supplement DXA if there is a specific reason for their use. Measurement of the lumbar sp ine and femoral neck is standard, but a different site or a single mea surement is recommended in specific cases. Unless accelerated bone los s is suspected, DXA should be repeated every 2 to 4 years for patients receiving ovarian hormone therapy and 1 to 2 years for patients under going bisphosphonate therapy. Measurements and reporting of results mu st be standardized. Reports should refer to the World Health Organizat ion's recommended definitions of osteopenia and osteoporosis and provi de actual measurement and its relation to peak bone mass. Validation: These recommendations were developed by the Scientific Advisory Board of the Osteoporosis Society of Canada at its 1993 Consensus Conference and revised in 1995. They agree with and expand upon recommendations of the United States National Osteoporosis Foundation. Sponsors: Spons ors of the 1993 conference include Merck Frosst Canada Inc., Proctor & Gamble Pharmaceuticals Canada, Inc., Rhone-Poulenc Rorer Canada Inc., Eli Lilly Canada Inc., Sandoz Canada Inc., Ciba-Geigy Canada Ltd., Or tho-McNeil Inc., the Dairy Bureau of Canada, Wyeth-Ayerst Canada Inc. and Lederle Laboratories.