The utility of portable dual-energy X-ray absorptiometry of the wrist in patients referred to a bone health clinic: a pilot study.
Fifty white female patients referred to a bone health care clinic were studied. Patients with a history of fracture were excluded. At the time of hip and spine dual-energy X-ray absorptiometry (DXA), those willing underwent portable dual-energy X-ray absorptiometry (pDXA) of the wrist. The mean age of the patients was 57 yr. Bone mineral density (BMD) assessment was performed on each patient at four different sites: posterior-anterior lumbar spine, nondominant hip, the distal radius and ulna, and the proximal radius and ulna of the nondominant arm. Comparison of the pDXA results with that of the conventional DXA results showed the highest correlation between pDXA of the distal radius and ulna (DR + U) and the DXA of the femoral neck and lumbar spine. By defining a pDXA (DR + U) T-score </= -1 as a positive test and DXA T-score </=-1 as the presence of disease, we obtained a specificity of 93% and a sensitivity of 82% for decreased lumbar spine bone density (positive predictive value 97% and the negative predictive value 70%) and a specificity of 100% and a sensitivity of 83% (positive predictive value is 100% and the negative predictive value is 70%) for decreased femoral neck bone density.