Comparison of three tools for predicting primary osteoporosis in an elderly male population in Beijing: a cross-sectional study

Abstract

Purpose: In this cross-sectional study, three clinical tools, the Osteoporosis Self-Assessment Tool for Asians (OSTA), Fracture Risk Assessment Tool (FRAX) without bone mineral density (BMD), and body mass index (BMI), for predicting primary osteoporosis (OP) were compared and ideal thresholds for omission of screening BMD were proposed in a community-dwelling elderly Han Beijing male population.

Patients and methods: A total of 1,349 community-dwelling elderly Han Beijing males aged ≥50 years were enrolled in this study. All subjects completed a questionnaire and measured BMD by dual-energy X-ray absorptiometry (DXA). Osteoporosis was defined as a T-score of -2.5 SD or lower than that of the average young adult in different diagnostic criteria (lumbar spine [L1-L4], femoral neck, total hip, worst hip, and World Health Organization [WHO]). FRAX without BMD, OSTA, and BMI were assessed for predicting OP by receiver operating characteristic (ROC) curves. Sensitivity, specificity, and areas under the ROC curves (AUCs) were determined. Ideal thresholds for omission of screening BMD were proposed.

Results: The prevalence of OP ranged from 1.8% to 12.8% according to different diagnostic criteria. This study showed that the BMI has highest discriminating ability. The AUC of FRAX without BMD ranged from 0.536 to 0.630, which suggested limiting predictive value for identifying OP in elderly Beijing male. The AUCs of BMI (0.801-0.880) were slightly better than OSTA (0.722-0.874) in predicting OP at all sites. The AUC of BMI to identify OP in worst hip was 0.824, yielding a sensitivity of 84.8% and a specificity of 64.4%. 40% of participants on BMD measurements saved only 0.1%-2.7% missed OP. Compared to OSTA and FRAX without BMD, the BMI got the best predictive value for OP.

Conclusion: BMI may be a simple and effective tool for identifying OP in the elderly male population in Beijing to omit BMD screening reasonably.

Keywords: BMI; FRAX; Fracture Risk Assessment Tool; OSTA; Osteoporosis Self-Assessment Tool for Asians; body mass index; male; osteoporosis.

Figure 1

The flow diagram of the study. Abbreviations: BMD, bone mineral density; BMI, body mass index; FRAX, Fracture Risk Assessment Tool; OSTA, Osteoporosis Self-Assessment Tool for Asians.

Figure 2

Comparison of different AUCs (BMI, OSTA, MOF, and HF for identifying osteoporosis) and sensitivity and specificity values according to worst hip criteria. Abbreviations: AUCs, areas under the receiver-operating characteristic curves; BMI, body mass index; FRAX, Fracture Risk Assessment Tool; HF, hip fractures; +LR, positive likelihood ratio; −LR, negative likelihood ratio; MOF, major osteoporotic fractures; OSTA, Osteoporosis Self-Assessment Tool for Asians.