Table 1.
Descriptives and differences between low-, average- and high-YYIR1 performance groups and effect by 2- and 4-year follow-up subsamples.
| Grand mean (n=21) | low (n=7) | average (n=7) | high (n=7) | MANOVA | Cohen’s d | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 2-year follow-up | Test | Mean (SD) | 95% CI | Mean (SD) | 95% CI | Mean (SD) | 95% CI | Mean (SD) | 95% CI | F-value | P-Value | Low-Average | Average-High | Low-High |
| Age (y) | 1 | 13.2 (.3) | ± .1 | 13.2 (.2) | ± .1 | 13.1 (.4) | ± .2 | 13.2 (.2) | ± .1 | .376 | .692 | .00 | .00 | .11 |
| 2 | 14.2 (.3) | ± .1 | 14.2 (.2) | ± .1 | 14.1 (.4) | ± .2 | 14.2 (.2) | ± .1 | .392 | .682 | .24 | .24 | .12 | |
| 3 | 15.2 (.3) | ± .1 | 15.2 (.2) | ± .1 | 15.2 (.3) | ± .1 | 15.2 (.2) | ± .1 | .345 | .713 | .24 | .24 | .24 | |
| Maturity OffSet (y) | 1 | -.85 (.51) | ± .12 | -.76 (.46) | ± .18 | -.60 (.49) | ± .20 | -1.20 (.43) | ± .17 | 3.287 | .061 | .16 | .09 | .11 |
| 2 | .14 (.72) | ± .16 | .27 (.58) | ± .23 | .44 (.76) | ± .30 | -.29 (.69) | ± .28 | 2.181 | .142 | .08 | .06 | .08 | |
| 3 | 1.17 (.70) | ± .16 | 1.36 (.49) | ± .20 | 1.45 (.85) | ± .34 | .70 (.52) | ± .21 | 2.849 | .084 | .07 | .03 | .03 | |
| Stature (cm) | 1 | 157.8 (6.5) | ± 1.5 | 158.4 (3.6) | ± 1.4 | 162.2 (6.5) | ± 2.6 | 152.8 (5.6) | ± 2.2 | 5.432 | .014Σ | .78 | 1.67 | 1.28 |
| 2 | 164.8 (7.5) | ± 1.7 | 165.7 (3.8) | ± 1.5 | 169.8 (7.8) | ± 3.1 | 159.0 (6.4) | ± 2.6 | 5.294 | .016Σ | .72 | 1.64 | 1.38 | |
| 3 | 171.1 (6.5) | ± 1.5 | 172.8 (2.9) | ± 1.2 | 174.6 (7.3) | ± 2.9 | 165.7 (5.2) | ± 2.1 | 5.272 | .016Σ | .35 | 1.52 | 1.82 | |
| Body mass (kg) | 1 | 46.0 (6.8) | ± 1.6 | 48.2 (6.6) | ± 2.6 | 49.3 (5.5) | ± 2.2 | 40.5 (5.0) | ± 2.0 | 4.863 | .020Σ | .20 | 1.81 | 1.42 |
| 2 | 52.7 (8.7) | ± 2.0 | 54.6 (7.6) | ± 3.0 | 57.0 (8.0) | ± 3.2 | 46.2 (7.6) | ± 3.0 | 3.592 | .049Σ | .33 | 1.50 | 1.19 | |
| 3 | 59.3 (8.8) | ± 2.0 | 62.5 (7.7) | ± 3.1 | 63.5 (7.9) | ± 3.2 | 52.0 (6.3) | ± 2.5 | 5.312 | .015Σ | .14 | 1.74 | 1.61 | |
| YYIR1 (m) | 1 | 1319(366) | ± 83 | 886(114) | ± 46 | 1357(100) | ± 40 | 1714(145) | ± 58 | 82.471 | <.001# | 4.74 | 3.10 | 6.86 |
| 2 | 1705(371) | ± 85 | 1366(360) | ± 144 | 1823(231) | ± 92 | 1926(265) | ± 106 | 7.386 | .005# | 1.63 | .45 | 1.91 | |
| 3 | 1823(427) | ±97 | 1411(252) | ± 101 | 1920(414) | ± 166 | 2137(220) | ± 88 | 10.296 | .001# | 1.60 | .71 | 3.32 | |
| Grand mean (n=21) | low (=7) | average (n=7) | high (n=7) | MANOVA | Cohen’s d | |||||||||
| 4-year follow-up | Test | Mean (SD) | 95% CI | Mean (SD) | 95% CI | Mean (SD) | 95% CI | Mean (SD) | 95% CI | F-value | P-value | Low-Average | Average-High | Low-High |
| Age (y) | 1 | 12.2 (.3) | ± .1 | 12.3 (.3) | ± .2 | 12.2 (.4) | ± .3 | 12.2 (.2) | ± .2 | .267 | .769 | .31 | .00 | .42 |
| 2 | 14.2 (.3) | ± .1 | 14.3 (.3) | ± .2 | 14.2 (.4) | ± .3 | 14.2 (.2) | ± .2 | .244 | .786 | .31 | .00 | .42 | |
| 3 | 16.2 (.3) | ± .1 | 16.3 (.3) | ± .2 | 16.3 (.4) | ± .3 | 16.1 (.3) | ± .2 | .462 | .638 | .00 | .61 | .72 | |
| Maturity OffSet (y) | 1 | -1.72 (.34) | ± .15 | -1.54 (.33) | ± .24 | -1.83 (.38) | ± .28 | -1.80 (.28) | ± .21 | 1.553 | .239 | .88 | .10 | .92 |
| 2 | .28 (.61) | ± .26 | .57 (.50) | ± .37 | .04 (.83) | ± .61 | .23 (.36) | ± .27 | 1.388 | .275 | .84 | .32 | .84 | |
| 3 | 2.14 (.47) | ± .20 | 2.28 (.23) | ± .17 | 2.11 (.63) | ± .47 | 2.04 (.52) | ± .39 | .431 | .657 | .39 | .13 | .64 | |
| Stature (cm) | 1 | 150.7 (3.6) | ± 1.5 | 152.5 (1.8) | ± 1.3 | 149.9 (3.4) | ± 2.5 | 149.7 (4.8) | ± 3.6 | 1.408 | .270 | 1.03 | .05 | .83 |
| 2 | 165.2 (5.2) | ± 2.2 | 167.8 (4.6) | ± 3.4 | 163.3 (5.6) | ± 4.2 | 164.5 (4.9) | ± 3.6 | 1.492 | .251 | .95 | .25 | .75 | |
| 3 | 174.6 (3.9) | ± 1.7 | 175.8 (4.1) | ± 3.0 | 174.3 (2.8) | ± 2.1 | 173.8 (4.8) | ± 3.6 | .497 | .647 | .46 | .14 | .48 | |
| Body mass (kg) | 1 | 39.5 (4.4) | ± 1.9 | 42.3 (5.0) | ± 3.7 | 37.9 (4.2) | ± 3.7 | 38.4 (2.8) | ± 2.1 | 2.375 | .121 | 1.03 | .15 | 1.04 |
| 2 | 52.3 (7.2) | ± 3.1 | 57.5 (8.7) | ± 6.4 | 48.5 (5.7) | ± 6.4 | 50.7 (3.6) | ± 2.7 | 3.781 | .043∞ | 1.32 | 1.10 | .15 | |
| 3 | 62.9 (5.1) | ± 2.2 | 66.7 (6.5) | ± 4.8 | 60.7 (3.0) | ± 4.8 | 61.2 (3.1) | ± 2.3 | 3.732 | .044∞ | 1.28 | 0.18 | 1.17 | |
| YYIR1 (m) | 1 | 1090(367) | ± 157 | 703(224) | ± 166 | 1063(128) | ± 95 | 1503(83) | ± 61 | 45.947 | <.001# | 2.13 | 4.41 | 5.12 |
| 2 | 1749(406) | ± 174 | 1686(194) | ± 144 | 1384(311) | ± 230 | 2177(202) | ± 150 | 19.281 | <.001Σ | 1.26 | 3.27 | 2.68 | |
| 3 | 2175(338) | ± 145 | 2126(373) | ± 276 | 1966(218) | ± 161 | 2434(248) | ± 184 | 4.801 | .021Σ | .57 | 2.17 | 1.05 | |
SD=standard deviation; CI=confidence interval;
# significant differences between all performance groups;
∞ Low is different from Average;
Σ high is different from low and average