Table 4

Technical error of measurement between two repeat measurements of adiposity using skinfold thickness taken 2–4 weeks apart

Number of paired measurements (n)Mean of paired measurementsDifference between
first and second measurement Mean (95% CI)
P valuesTechnical error measurement (CV)
Non-standers (n=30)
 Mid-upper arm circumference (cm)2822.1−0.5 (−0.9 to 0.1)0.030.82 (3.72)
 Triceps skinfold thickness (mm)2715.5−0.5 (−1.6 to 0.6)0.41.94 (12.5)
 Triceps SDS270.75−0.13 (−0.36 to 0.11)0.45 (59.43)
 Biceps skinfold thickness (mm)269.3−0.0 (−1.5 to 1.5)1.02.36 (25.6)
 Subscapular skinfold thickness (mm)2612.1−0.5 (−2.0 to 0.3)0.21.28 (8.3)
 Subscapular SDS260.331.23 (0.48 to 1.97)0.34 (102.33)
 Suprailiac skinfold thickness (mm)
Standers (n=23)
 Mid-upper arm circumference (cm)2226.1−0.1 (−0.7 to 0.5)0.70.91 (3.5)
 Triceps skinfold thickness (mm)1717.21.4 (−0.7 to 3.5)0.22.99 (17.4)
 Triceps SDS171.09−0.17 (−0.45 to 0.12)0.110.39 (36.3)
 Biceps skinfold thickness (mm)1616.41.1 (−1.2 to 3.5)0.33.11 (19.03)
 Subscapular skinfold thickness (mm)1216.4−2.6 (5.4 to 0.2)0.063.49 (21.29)
 Subscapular SDS121.18−0.12 (−0.3 to 0.06)0.080.2 (17.5)
 Suprailiac skinfold thickness (mm)818.90.1 (−3.1 to 4.0)0.82.79 (14.8)
  • SDS using LMS method12; difference in means P value assessed by paired t-test; TEM=√∑d2⁄2 n, where d is difference between two measurements and n is no. of measurements. CV: 100xTEM/mean of measurements taken, expressed as a percentage.

  • CV, coefficient of variability; LMS, L skewness M median S coefficient of variation; SDS, SD score.