Trial arm | Intervention | Control | Effect size* (90% CL) | (% higher | trivial | lower)† Inference | p-Value |

Age (years) | 16.0±1.2 | 15.9±1.1 | 0.06 (0.00 to 0.14) | (0 | 100 | 0%) Most likely trivial | 0.19 |

Stature (cm) | 177.4±7.3 | 176.6±7.5 | 0.11 (0.03 to 0.19) | (4 | 96 | 0%) Very likely trivial | 0.03 |

Body mass (kg) | 74.7±12.9 | 72.5±13.1 | 0.17 (0.09 to 0.25) | (27 | 73 | 0%) Possibly trivial | <0.01 |

Maturity offset (%) | |||||

>1 year post-PHV | 642 (71%) | 586 (70%) | 1.03 (0.91 to 1.16) | (4 | 95 | 1%) Very likely trivial | 0.68 |

<1 year post-PHV | 261 (29%) | 251 (30%) |

Data presented as mean ± SD or as raw frequency (%) where specified.

*Effect sizes for age, stature and body mass expressed as Cohen’s d; effect size for maturity offset expressed as a proportion ratio.24

†Percentage likelihood of effect being higher or lower is analogous to effect favouring intervention or control, respectively.

CL, confidence limits; PHV, peak height velocity.