TABLE 3.
Cross-validation of the NiPPeR and the University of Queensland (UQ) BIA prediction equations.
| Origin | Parameters | Equation | Destination | MAPE | CCC | Bias | SD | LOA | p | ||||
| NiPPeR | 6 week | M | W + L | −1.07 + 0.62W + 0.03L | UQ | 6 week | M | 6.82% | 0.729 | −0.279 (−6.64%) | 0.154 (3.67%) | −0.581, 0.023 | 0.053 |
| F | −1.06 + 0.51W + 0.04L | F | 4.35% | 0.753 | −0.129 (−3.39%) | 0.183 (4.82%) | −0.488, 0.230 | 0.093 | |||||
| M | W + L + GA + BWSDS | −2.48 + 0.51W + 0.01L + 0.08GA + 0.07BWSDS | M | 4.28% | 0.831 | −0.165 (−3.93%) | 0.144 (3.43%) | −0.448, 0.118 | 0.581 | ||||
| F | −2.39 + 0.38W + 0.03L + 0.06GA + 0.08BWSDS | F | 6.43% | 0.633 | −0.226 (−5.95%) | 0.186 (4.89%) | −0.591, 0.139 | 0.056 | |||||
| M | W + L + GA + BWSDS + SS + AC | −3.14 + 0.48W + 0.02L + 0.07GA + 0.03BWSDS − 0.04SS + 0.03AC | M | 2.80% | 0.908 | 0.001 (0.02%) | 0.154 (3.67%) | −0.300, 0.302 | 0.410 | ||||
| F | −2.27 + 0.43W + 0.03L + 0.05GA + 0.06BWSDS − 0.04SS + 0.02AC | F | 5.63% | 0.694 | 0.172 (4.53%) | 0.187 (4.92%) | −0.195, 0.540 | 0.046 | |||||
| M | W + L2/R50 | 0.23 + 0.65W + 0.10L2/R50 | M | 3.23% | 0.884 | −0.021 (−0.50%) | 0.194 (4.62%) | −0.402, 0.360 | 0.048 | ||||
| F | 0.60 + 0.58W + 0.08L2/R50 | F | 3.29% | 0.783 | −0.020 (−0.53%) | 0.197 (5.18%) | −0.406, 0.366 | 0.047 | |||||
| M | W + L2/R50 + GA + BWSDS | −2.00 + 0.52W + 0.05L2/R50 + 0.08GA + 0.06BWSDS | M | 3.04% | 0.903 | 0.051 (1.21%) | 0.154 (3.67%) | −0.252, 0.353 | 0.926 | ||||
| F | −1.08 + 0.45W + 0.04L2/R50 + 0.06GA + 0.08BWSDS | F | 3.96% | 0.750 | −0.090 (−2.37%) | 0.197 (5.18%) | −0.477, 0.297 | 0.038 | |||||
| M | W + L2/R50 + GA + BWSDS + SS + AC | −2.42 + 0.52W + 0.01L2/R50 + 0.07GA + 0.04BWSDS − 0.03SS + 0.03AC | M | 3.13% | 0.882 | −0.086 (−2.05%) | 0.158 (3.76%) | −0.395, 0.223 | 0.852 | ||||
| F | −1.11 + 0.52W + 0.03L2/R50 + 0.05GA + 0.06BWSDS − 0.04SS + 0.01AC | F | 5.70% | 0.636 | −0.191 (−5.03%) | 0.197 (5.18%) | −0.577, 0.195 | 0.011 | |||||
| 6 month | M | W + L | −2.94 + 0.37W + 0.09L | 4.5 month | M | 6.42% | 0.784 | 0.308 (5.70%) | 0.213 (3.94%) | −0.110, 0.726 | 0.353 | ||
| F | −2.32 + 0.37W + 0.07L | F | 4.84% | 0.564 | 0.102 (2.08%) | 0.303 (6.18%) | −0.490, 0.695 | 0.270 | |||||
| M | W + L + GA + BWSDS | −3.49 + 0.29W + 0.07L + 0.06GA + 0.12BWSDS | M | 7.30% | 0.725 | 0.350 (6.48%) | 0.231 (4.28%) | −0.102, 0.802 | 0.075 | ||||
| F | −3.68 + 0.35W + 0.06L + 0.06GA + 0.06BWSDS | F | 6.02% | 0.486 | −0.170 (−3.47%) | 0.324 (6.61%) | −0.806, 0.466 | 0.301 | |||||
| M | W + L + GA + BWSDS + SS + AC | −1.63 + 0.37W + 0.05L + 0.04GA + 0.09BWSDS − 0.06SS + 0.004AC | M | 5.91% | 0.735 | 0.266 (4.93%) | 0.262 (4.85%) | −0.248, 0.780 | < 0.001 | ||||
| F | −0.88 + 0.56W + 0.03L + 0.04GA + 0.06BWSDS − 0.06SS − 0.03AC | F | 6.13% | 0.404 | 0.156 (3.18%) | 0.354 (7.22%) | −0.537, 0.849 | 0.076 | |||||
| M | W + L2/R50 | 1.26 + 0.46W + 0.14L2/R50 | M | 3.46% | 0.920 | 0.110 (2.04%) | 0.191 (3.54%) | −0.263, 0.484 | 0.723 | ||||
| F | 1.40 + 0.36W + 0.21L2/R50 | F | 5.73% | 0.526 | −0.245 (−5.00%) | 0.276 (5.63%) | −0.786, 0.295 | 0.330 | |||||
| M | W + L2/R50 + GA + BWSDS | −0.11 + 0.37W + 0.09L2/R50 + 0.06GA + 0.12BWSDS | M | 5.54% | 0.822 | 0.260 (4.81%) | 0.196 (3.63%) | −0.124, 0.645 | 0.082 | ||||
| F | −1.47 + 0.32W + 0.20L2/R50 + 0.08GA + 0.07BWSDS | F | 6.43% | 0.480 | −0.258 (−5.27%) | 0.303 (6.18%) | −0.851, 0.335 | 0.328 | |||||
| M | W + L2/R50 + GA + BWSDS + SS + AC | 0.74 + 0.47W + 0.07L2/R50 + 0.05GA + 0.08BWSDS − 0.08SS − 0.01AC | M | 5.13% | 0.780 | 0.104 (1.93%) | 0.296 (5.48%) | −0.477, 0.685 | < 0.001 | ||||
| F | 0.76 + 0.57W + 0.23L2/R50 + 0.04GA + 0.06BWSDS − 0.08SS − 0.05AC | F | 7.02% | 0.443 | 0.099 (2.02%) | 0.392 (8.00%) | −0.671, 0.868 | 0.295 | |||||
| UQ | 6 week | W + S + L | 0.260 + 0.528W − 0.125S + 0.022L | NiPPeR | 6 week | M | 4.63% | 0.822 | 0.092 (2.36%) | 0.200 (5.13%) | −0.300, 0.485 | < 0.001 | |
| F | 4.48% | 0.810 | 0.073 (2.03%) | 0.199 (5.53%) | −0.317, 0.462 | < 0.001 | |||||||
| W + S + L2/R0 | 1.169 + 0.568W − 0.128S + 0.032L2/R0 | M | 7.08% | 0.695 | 0.243 (6.23%) | 0.199 (5.10%) | −0.148, 0.633 | < 0.001 | |||||
| F | 6.76% | 0.702 | 0.195 (5.42%) | 0.206 (5.72%) | −0.209, 0.598 | < 0.001 | |||||||
| W + S + L2/R∞ | 1.322 + 0.588W − 0.148S + 0.009L2/R∞ | M | 4.74% | 0.808 | 0.101 (2.59%) | 0.205 (5.26%) | −0.300, 0.502 | < 0.001 | |||||
| F | 4.93% | 0.798 | 0.067 (1.86%) | 0.207 (5.75%) | −0.339, 0.472 | < 0.001 | |||||||
| W + S + L2/Zc | 1.253 + 0.585W − 0.143S + 0.001L2/Zc | M | 4.81% | 0.804 | 0.107 (2.74%) | 0.205 (5.26%) | −0.294, 0.508 | < 0.001 | |||||
| F | 4.98% | 0.795 | 0.072 (2.00%) | 0.207 (5.75%) | −0.333, 0.478 | < 0.001 | |||||||
| W + S + L2/R50 | 1.248 + 0.584W − 0.142S + 0.002L2/R50 | M | 4.48% | 0.825 | 0.088 (2.26%) | 0.199 (5.10%) | −0.302, 0.479 | < 0.001 | |||||
| F | 4.79% | 0.806 | 0.058 (1.61%) | 0.204 (5.67%) | −0.342, 0.458 | < 0.001 | |||||||
| 4.5 month | W + S + L | −0.044 + 0.397W − 0.427S + 0.045L | 6 month | M | 4.66% | 0.693 | −0.051 (−0.89%) | 0.339 (5.95%) | −0.715, 0.613 | < 0.001 | |||
| F | 6.64% | 0.541 | −0.264 (−5.08%) | 0.346 (6.65%) | −0.942, 0.414 | < 0.001 | |||||||
| W + S + L2/R0 | 1.909 + 0.280W − 0.279S + 0.305L2/R0 | M | 4.63% | 0.666 | −0.063 (−1.11%) | 0.343 (6.02%) | −0.735, 0.610 | < 0.001 | |||||
| F | 6.35% | 0.539 | −0.256 (−4.92%) | 0.345 (6.63%) | −0.932, 0.420 | < 0.001 | |||||||
| W + S + L2/R∞ | 2.484 + 0.416W − 0.430S + 0.040L2/R∞ | M | 4.56% | 0.669 | −0.091 (−1.60%) | 0.343 (6.02%) | −0.764, 0.582 | < 0.001 | |||||
| F | 6.07% | 0.562 | −0.263 (−5.06%) | 0.336 (6.46%) | −0.921, 0.396 | < 0.001 | |||||||
| W + S + L2/Zc | 2.059 + 0.313W − 0.320S + 0.201L2/Zc | M | 4.61% | 0.674 | −0.134 (−2.35%) | 0.337 (5.91%) | −0.795, 0.528 | < 0.001 | |||||
| F | 6.33% | 0.566 | −0.284 (−5.46%) | 0.330 (6.35%) | −0.931, 0.363 | < 0.001 | |||||||
| W + S + L2/R50 | 2.203 + 0.334W − 0.361S + 0.185L2/R50 | M | 4.87% | 0.673 | −0.100 (−1.75%) | 0.351 (6.16%) | −0.788, 0.587 | < 0.001 | |||||
| F | 6.04% | 0.585 | −0.247 (−4.75%) | 0.336 (6.46%) | −0.906, 0.412 | < 0.001 | |||||||
AC, abdominal circumference (cm); BWSDS, INTERGROWTH-21st birthweight standard deviation score; CCC, Lin’s concordance correlation coefficient; GA, gestational age (weeks); L, length (cm); LOA, 95% limits of agreement; MAPE, mean absolute percentage error; R0, resistance at very low, i.e. 0 kHz (Ω); R50, resistance at 50 kHz (Ω); R∞, resistance at very high, i.e. ∞ kHz (Ω); SD, standard deviation; SS, subscapular skinfold thickness (mm); W, weight (kg); ZC, impedance at the characteristic frequency (Ω).