Comparison of speed of sound ultrasound with single photon absorptiometry for determining fracture odds ratios.

The purpose of this study was to compare the ability of ultrasound velocity measurement with that of single photon absorptiometry to determine the odds of history of fracture since age 40, for a population-based study. To do this we computed odds ratios and 95% confidence intervals for 809 women and 502 men, aged 50 years and older, who are participants in the prospective phase of the Saunders County Bone Quality Study. These participants received both the ultrasound and single photon absorptiometry bone measurements at the initiation of the study. In addition, a history of all fractures that had occurred to participants since age 40 was obtained. The two bone assessment methods were compared by examining the magnitude of the odds ratios, to determine which produces the highest estimate of the probability of odds of fracture, and by examining widths of the respective confidence intervals to show which estimate of odds ratio is the most precise. Ultrasound velocity estimates a higher probability of odds of both low-trauma fractures and all fractures than distal radius and ulna bone mineral content, but lower than bone mineral density at the same sites for both women and men. However, the ultrasound measure is more precise than bone mineral density, but less precise than bone mineral content. We conclude that ultrasound velocity is as good as single photon absorptiometry in estimating odds of fracture.