Performance of screening tools for osteoporosis and fractures in community-dwelling elderly Japanese men

The Osteoporosis Self-Assessment Tool for Asians (OSTA) was originally developed for postmenopausal Asian women, but its performance in men is inadequately characterized. This study evaluated the diagnostic accuracy of OSTA for identifying osteoporosis and predicting major osteoporotic fractures (MOF) in elderly Japanese men, and compared its fracture prediction capability with the fracture risk assessment tool (FRAX^®).

Data were drawn from the Fujiwara-kyo Osteoporosis Risk in Men (FORMEN) cohort. The primary analysis included 1888 men aged 65-94 years. Osteoporosis was defined by dual-energy X-ray absorptiometry (DXA)-derived T-score ≤-2.5 at the lumbar spine, total hip, or femoral neck. OSTA and FRAX^® 10-year MOF probability were calculated at baseline. Optimal cutoff values were determined using the Youden index. A sub-analysis for MOF prediction was conducted in 866 men with 10-year follow-up data.

The area under the curve (AUC) of OSTA for identifying osteoporosis was 0.777 (95% CI 0.714-0.840) in men aged 65-74 years and 0.739 (95% CI 0.666-0.812) in those aged ≥75 years. Optimal OSTA cutoff values (- 3 and -5, respectively) differed substantially from the conventional female-derived threshold of ≤-1. For MOF prediction, the AUC of OSTA was not significantly different from that of FRAX^®.

OSTA demonstrated moderate discriminative ability for DXA-defined osteoporosis in elderly Japanese men; however, age-specific cutoff values are required. The comparable fracture prediction performance of OSTA and FRAX^® supports the utility of this simple index as a first-line screening tool in men.