Leslie William D, Aftabi Sajjad, Schousboe John T, Krueger Diane, Binkley Neil
University of Manitoba, Winnipeg, Canada.
Park Nicollet Clinic and HealthPartners Institute, HealthPartners, Minneapolis, USA; University of Minnesota, Minneapolis, USA.
J Clin Densitom. 2025 Oct-Dec;28(4):101620. doi: 10.1016/j.jocd.2025.101620. Epub 2025 Jul 22.
Bone mineral density (BMD) measurement with dual-energy X-ray absorptiometry (DXA) is widely used to assess osteoporosis and monitor BMD in untreated and treated individuals. Systematic sources of error can occur with DXA scanners, including calibration drift. Publications suggest a drift tolerance in the range 0.5 % to 1.5 %, but are not evidence- based. The current study was performed to directly determine how varying degrees of simulated DXA calibration drift would affect misclassification of BMD change in routine clinical practice. Using data from the Manitoba Bone Density Program, we accessed results for 14,942 individuals age 40 years and older undergoing baseline and repeat fan-beam DXA measurements of the total hip within an interval of 1-5 years. A small amount of simulated drift (absolute 0.003 g/cm or relative 0.25 %) had little effect, and resulted in less than 5 % BMD change misclassification. Misclassification exceeded 10 % with absolute BMD drift greater than 0.006 g/cm or relative drift over 0.75 %, and was greater than 35 % for absolute BMD drift of 0.024 g/cm. Similar trends were seen when results were stratified according to use of anti-osteoporosis medication, when varying the least significant change (LSC), and for evaluating lumbar spine BMD change. In summary, relatively small degrees of DXA calibration drift can have large effects on misclassifying BMD change. Our results support a calibration drift tolerance of 0.006 g/cm or 0.5 %. These findings may help to guide timing for DXA scanner servicing and repair.
采用双能X线吸收法（DXA）测量骨密度（BMD）被广泛用于评估骨质疏松症以及监测未接受治疗和正在接受治疗个体的骨密度。DXA扫描仪可能会出现系统性误差来源，包括校准漂移。出版物提出的漂移容限范围为0.5%至1.5%，但并非基于证据。本研究旨在直接确定不同程度的模拟DXA校准漂移如何影响常规临床实践中骨密度变化的错误分类。利用马尼托巴骨密度项目的数据，我们获取了14942名40岁及以上个体的结果，这些个体在1至5年的间隔内接受了全髋部的基线和重复扇形束DXA测量。少量的模拟漂移（绝对漂移0.003 g/cm或相对漂移0.25%）影响很小，导致骨密度变化错误分类不到5%。当绝对骨密度漂移大于0.006 g/cm或相对漂移超过0.75%时，错误分类超过10%，当绝对骨密度漂移为0.024 g/cm时，错误分类大于35%。根据抗骨质疏松药物的使用情况进行分层、改变最小有意义变化（LSC）以及评估腰椎骨密度变化时，也观察到了类似趋势。总之，相对较小程度的DXA校准漂移可能会对骨密度变化的错误分类产生很大影响。我们的结果支持0.006 g/cm或0.5%的校准漂移容限。这些发现可能有助于指导DXA扫描仪的维护和维修时机。
