Validation of the Simple Calculated Osteoporosis Risk Estimation (SCORE) for patient selection for bone densitometry

Bone densitometry using dual energy X-ray absorptiometry (DXA) is the 'gold standard' for osteoporosis diagnosis. However, mass screening for osteopor osis has not been recommended, and no consensus has been reached regarding specific targeted screening programs. Recently, the Simple Calculated Osteo porosis Risk Estimation (SCORE) was developed to identify postmenopausal wo men likely to have low BMD (less than or equal to -2.0 SD of the young adul t normal), who may be selected for DXA testing. This instrument uses a case -selective approach to screen for osteoporosis by summing a score based on: age, race, rheumatoid arthritis, history of nontraumatic fracture over 45 years of age, estrogen use, and weight. In our study, SCORE was validated u sing 398 postmenopausal women at least 45 years of age residing within 50 k m of Toronto, Ontario, Canada (one of 9 centers of the Canadian Multicentre Osteoporosis Study, a national population-based study). At the recommended threshold of 6, SCORE had a sensitivity of 90%, specificity of 32% and a p ositive predictive value of 64%. From receiver operating characteristic (RO C) analysis, no threshold identified SCORE as a useful instrument in our po pulation; area under the ROC curve was 0.71. Specificity of the SCORE is po or; at the recommended threshold of 6, 68% of those with normal bone minera l density (BMD) would be selected for bone densitometry. Development and va lidation of SCORE by Lydick and colleagues may have been confounded by the nature of the study sample; sampling from specialty clinics; and by the cho ice of outcome, combining data from different DXA machines, and using only data from the femoral neck to identify low BMD. A simple and effective appr oach to select patients for bone densitometry has yet to be established.