Table 2 Mean difference, Pearson correlation coefficient, intra-class correlation coefficient, and kappa coefficient for reported and measured height, weight, and body mass index (BMI)
Measured minus self-reported values | Pearson correlation coefficient | Intra-class correlation coefficient and 95% CI | Non-weighted kappa coefficient (SE) for categorised BMI | Regression equation of reported in terms of measured data:regression coefficient and 95% CI | |||||
|---|---|---|---|---|---|---|---|---|---|
Mean (SD) | <0 (%) | Zero (%) | >0(%) | Slope | Constant term | ||||
Boys (N = 708) | |||||||||
Height (m) | 0.0069 (0.33) | 28.8 | 24.6 | 46.6 | 0.96 | 0.92 (0.89-0.95) | - | 1.00 (0.98-1.02) | −0.01 (−0.045-0.025) |
Weight (kg) | 1.03 (2.63) | 21.5 | 11.9 | 66.7 | 0.98 | 0.96 (0.95-0.97) | - | 0.96 (0.94-0.97) | 1.06 (0.25-1.88) |
BMI (kg/m2) | 0.22 (1.21) | 32.8 | 6.6 | 60.6 | 0.92 | 0.90 (0.84-0.96) | 0.66 (0.027) | 0.90 (0.87-0.93) | 1.72 (1.16-2.28) |
Girls (N = 693) | |||||||||
Height (m) | 0.0016 (0.023) | 33.3 | 28.4 | 38.2 | 0.96 | 0.93 (0.89-0.96) | - | 1.03 (1.01-1.05) | −0.045 (−0.079- -0.011) |
Weight (kg) | 0.81 (2.22) | 23.5 | 11.4 | 65.1 | 0.98 | 0.96 (0.95-0.97) | - | 0.97 (0.96-0.99) | 0.61 (−0.19-1.41) |
BMI (kg/m2) | 0.29 (1.12) | 31.8 | 5.5 | 62.8 | 0.94 | 0.88 (0.83-0.93) | 0.75 (0.029) | 0.93 (0.90-0.95) | 1.18 (0.66-1.69) |
Total sample (N = 1401) | |||||||||
Height (m) | 0.0043 (0.29) | 31.0 | 26.5 | 42.5 | 0.96 | 0.96 (0.95-0.96) | - | 1.01(0.99-1.02) | −0.014 (−0.038-0.011) |
Weight (kg) | 0.92 (2.44) | 22.5 | 11.6 | 65.9 | 0.98 | 0.92 (0.89-0.95) | - | 0.96 (0.95-0.97) | 0.92 (0.35-1.49) |
BMI (kg/m2) | 0.25 (1.17) | 32.3 | 6.1 | 61.7 | 0.93 | 0.88 (0.85-0.91) | 0.70 (0.020) | 0.91 (0.89-0.93) | 1.44 (1.06-1.83) |