A retrospective study of 696 postmenopausal women with hip measurement by Dual-energy X-ray absorptionmetry (DEXA) from Sapphasittprasong Hospital, Ubon Rahatani and Srinagarind Hospital,Khon Kaen University. All variables : T-score , age and weight were collected and calculated by the original OSTA index and modified OSTA index. Thai osteoporosis foundation recognized Original OSTA index the cut point below or equal 4 as high risk of osteoporosis. The authors used the modified OSTA index for calculation without truncate, the authors found that the cut off point was <-3.5 making 79 % sensitivity and 58.7% specificity while the original OSTA gave 73%, 62% respectively. The authors proposed modified OSTA index as a making-decision tool before sending the patient for bone mass measurement. That saves the expense of further investigation.

Keywords: OSTA index, DEXA measurement