The added value of trabecular bone score to FRAXA® to predict major osteoporotic fractures for clinical use in Chinese older people: the Mr. OS and Ms. OS cohort study in Hong Kong

The association of trabecular bone score (TBS) with fracture risk and its added predictive value to FRAXA (R) for clinical use have never been independently evaluated in a Chinese population. TBS may improve the predictive power of FRAXA (R) for clinical use in older Chinese men. Trabecular bone score (TBS) of lumbar spine on Dual X-ray densitometry provides information on bone architecture. We therefore examined the additive value of TBS to FRAXA (R) in predicting major osteoporotic fractures (MOFs) in older Chinese people. Four thousand community-dwelling Chinese men and women aged ae65 years were followed up for fracture incidence for an average period of 9.94 and 8.82 years, respectively. At baseline, areal BMD of hip and lumbar spine were measured by DXA, TBS was estimated for the lumbar spine, and FRAXA (R) for 10-year risk of MOFs (hip, clinical spine, shoulder, and wrist) was estimated. Cox regression model was used to evaluate the associations between TBS and FRAXA (R) with the MOFs risk. The area under receiver-operating characteristic curve (AUC), integrated discrimination improvement (IDI), and category-based net reclassification improvement (NRI) were applied to evaluate the improved prediction ability. During the follow-up, 126 men and 215 women had at least one incident MOF. Each SD decrease in TBS was significantly associated with incident MOFs, with HR (95%CI) of 1.53 (1.30-1.80) and 1.40 (1.22-1.61) in men and women, respectively. TBS-adjusted FRAXA (R) predicts better than FRAXA (R) with a significantly increased AUC and IDI in men. Using specific intervention thresholds, TBS-adjusted FRAXA (R) brings about 5 % overall correct reclassification for MOFs prediction than FRAXA (R) in men. The increased correct MOFs risk classifications were not significant in older women. TBS-adjusted FRAXA (R) may improve the predictive power of FRAXA (R) on MOFs for clinical use in older Chinese men.