RESUMEN
The purpose of this study was to assess the performance of an osteoporosis self-assessment tool for Asians (OSTA) for screening middle-aged and old healthy women in the Chengdu region of China. OSTA scores were used to evaluate the effect of age on the development of osteoporosis. A total of 15,752 healthy women older than 40 yr, who reside in the Chengdu region, were assigned to 9 age groups divided by 5-yr intervals. Bone mineral density of the lumbar vertebrae, L1-L4, and the left hip was measured with a GE Lunar Prodigy advance dual-energy X-ray absorptiometry system (GE Healthcare, Cincinnati, OH). All subjects were classified into 3 categories according to OSTA cutoff values. The OSTA values used to define the categories were ≥-1, >-4 and <-1, and ≤-4. The accuracy of the OSTA index was compared with T-scores measured by dual-energy X-ray absorptiometry at various skeletal sites. All statistical analyses were performed using SPSS, version 17.0 (SPSS, Inc., Chicago, IL). The detection rate of osteoporosis and osteopenia at the lumbar vertebrae and the femur was found to increase with age. Furthermore, the sensitivity of OSTA value for detection of osteoporosis also gradually enhanced with subject age. In contrast, the specificity gradually decreased with age. The sensitivity and negative predictive value of the OSTA index for detecting osteoporosis gradually increased with higher OSTA cutoff values, and the specificity and positive predictive value appeared to gradually decline. It was concluded that the OSTA is a useful screening tool to detect osteoporosis in middle-aged and old women in the Chengdu region of China. Furthermore, specific OSTA cutoff values should be selected for screening individuals who belong to different age groups.