Quality and performance measures in bone densitometry
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This is part 2 of a core chapter of the forthcoming Report on Bone Densitometry commissioned by the International Commission on Radiation Units (ICRU). It is written with the aim to review definitions of quantities and units used in bone densitometry research and to describe parameters and methods that can be used to compare and standardize densitometric equipment and measurements. Part 2 of this chapter contains the section on fracture risk.
Performance measures in the assessment of fracture risk
Building on concepts of risk assessment, including risk ratios and odds ratios, we review statistical concepts commonly used in cross-sectional and prospective fracture studies. Performance measures are defined that allow a comparison of the ability of densitometry techniques to assess fracture risk.
The methods of discriminant analysis, logistic regression, Poisson regression models, and the Cox proportional hazard model are presented and compared. In addition, statistical concepts to characterize risk for the individual patient are reviewed.
KeywordsBone densitometry Fracture risk Performance Quality
The study was supported by travel grants of the International Commission on Radiation Units (ICRU). We thank the ICRU for the possibility to separately publish a part of the forthcoming report on bone densitometry. Members of the report committee are W. Kalender, Institute of Medical Physics, University of Erlangen (head); P. Laugier, Laboratoire d’Imagérie Paramétrique, Université Paris IV; J. Shepherd, Department of Radiology, University of California San Francisco; T. Fuerst, Synarc Inc., San Francisco; and two of the authors of this article (KE and CCG).
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