# Performance of the Osteoporosis Self-Assessment Tool for Asians (OSTA) Index for Osteoporosis Screening in Thai Men: A Cross-Sectional Study

## TL;DR

This study evaluates the OSTA index's effectiveness in predicting osteoporosis in Thai men and finds the KKOS score to be a better screening tool.

## Contribution

The study compares the OSTA index with the KKOS score and age cutoff for osteoporosis screening in Thai men, identifying the most effective method.

## Key findings

- The OSTA index cutoff of −1 had higher sensitivity but lower specificity than −4 for predicting osteoporosis.
- The KKOS score ≤−1 outperformed the OSTA index ≤−1 in predicting osteoporosis (AUC 0.636 vs. 0.594).
- An age cutoff of ≥70 years was less effective than both the OSTA and KKOS methods.

## Abstract

Background

Addressing the under-recognition of osteoporosis in men necessitates the use of suitable screening tools tailored to the male population. The Osteoporosis Self-Assessment Tool for Asians (OSTA) index is a reliable tool for evaluating the risk of osteoporosis. This cross-sectional study aims to assess the predictive performance of the OSTA index in Thai men. Additionally, the study compares the performance of the OSTA index with the Khon Kaen Osteoporosis Study (KKOS) score and an age cutoff value of ≥70 years.

Methods

Between November 2017 and October 2024, men aged 50 years or older who underwent dual-energy X-ray absorptiometry and did not receive any osteoporosis treatment were included. The performance of the individual OSTA index cutoff values in predicting osteoporosis was assessed.

Results

A total of 427 men were included in this study and classified into normal bone mineral density (BMD) (175 men, 41%), osteopenia (210 men, 49.2%), and osteoporosis (42 men, 9.8%). The mean age, weight, and body mass index were 76.4 years, 65.9 kg, and 24.1 kg/m², respectively. The OSTA index cutoff of −1 at any BMD site produced a Youden index of 0.187, with a sensitivity of 85.7% and a specificity of 33%. Meanwhile, the OSTA index cutoff of −4 at any BMD site resulted in a Youden index of 0.395, with a sensitivity of 59.5% and a specificity of 80%. The area under the receiver operating characteristic curve (AUC) of the KKOS score ≤−1 was 0.636. The AUC of the OSTA index ≤−1 was 0.594, which was significantly lower than the AUC of the KKOS score ≤−1 (P = 0.003). The AUC of age ≥70 years was 0.494, which was significantly lower than the AUC of the OSTA index ≤−1 (P < 0.001).

Conclusion

For osteoporosis screening in Thai men, the OSTA index cutoff value of −1 is more appropriate than a cutoff value of −4. However, the KKOS score cutoff value of ≤−1 serves as the most effective predictor for osteoporosis screening.