Measurement Error of DXA: Interpretation of Fat and Lean Mass Changes in Obese and Non-Obese Children

Assessing methods to specify the target difference for a randomised controlled trial: DELTA (Difference ELicitation in TriAls) review

“…A very common approach is to use test-retest data for an outcome to specify the magnitude of difference that could be due to random variation in the measurement. 459 The limited usefulness for calculating the MCID, or an important difference, has been noted by a number of authors although this method has been used alongside other methods. 456 An extension to the measurement error approach is the RCI, which uses the former approach but also involves reference to 'normative' and 'abnormal' populations and defining a cut-off between the two.…”

Effect of puberty on body composition

“…It is a highly available technique, with relatively little radiation exposure, though it cannot distinguish subcutaneous from visceral fat stores unless narrow cuts are used. Fat mass calculations are less accurate in lean children and fat free mass calculations are less accurate in obese children [13]. Quantitative CT is accurate [14,15], but not widely used in pediatric patients due to high radiation exposure, a concern of particular importance in children [16].…”

Precision Errors, Least Significant Change, and Monitoring Time Interval in Pediatric Measurements of Bone Mineral Density, Body Composition, and Mechanostat Parameters by GE Lunar Prodigy

“…Our study provided absolute and percent precision errors of a wide spectrum of bone, body composition, and mechanostat parameters that were established in 147 children aged 5e18 yr. Our results are in general agreement with the study of Margulies et al (13) who showed slightly higher percent precision errors for TBBMC (2.82%), LBM (1.29%), FM (2.59%), and similar percent precision error for TBBMD (0.73%). Wosje et al (14) in the precision study of QDR 4500A (Hologic, Bedford, MA) on 32 obese and 34 nonobese children aged 6e19 yr noted that CV% for FM was lower in obese (1.29%) than nonobese children (1.89%). In contrast, LBM percent precision error was higher for obese (0.94%) than nonobese children (0.48%), whereas precision error for bone mass was similar in both groups of children (14).…”

“…Wosje et al (14) in the precision study of QDR 4500A (Hologic, Bedford, MA) on 32 obese and 34 nonobese children aged 6e19 yr noted that CV% for FM was lower in obese (1.29%) than nonobese children (1.89%). In contrast, LBM percent precision error was higher for obese (0.94%) than nonobese children (0.48%), whereas precision error for bone mass was similar in both groups of children (14). In the precision study of bone and body composition measures of 15 young children (aged !10 yr; 9 girls and 6 boys) and 17 older children (aged 10e18 yr; 9 girls and 8 boys) with the use of Discovery A device (Hologic, Bedford, MA) calculated CV% for TBBMC (1.4%), TBBMD (1.1%), LBM (0.9%), and FM (2.4%) were also similar to our results; however, in contrast to our findings, absolute precision error values for TBBMD, SBMD, LBM, and FM were not related to age of investigated children, except TBBMC (r 5 0.44; p !…”