Fixed Effect Parameters | Means Only | Straight Line (Covariance: Identity) | Straight Line (Covariance: Unstructured) | Straight Line (Covariance: Unstructured) | Straight Line (Covariance: Unstructured) |

Intercept | 11.8 [11.5, 12.1]^{a} | 11.8 [11.5, 12.1]^{a} | 11.9 [11.6, 12.2]^{a} | 12.5 [12.1, 12.9]^{a} | 12.5 [12.1, 12.9]^{a} |

Epo dose | | | | −0.15 [−0.22, − 0.08]^{a} | −0.19 [−0.27, −0.11]^{a} |

Epo dose × time^{c} | | | | | 0.03 [0.001, 0.06]^{b} |

Random effect parameters | | | | | |

SD Intercept | 1.22 | 1.29 | 1.63 | 1.51 | 1.52 |

SD Time | NA | 0.45 | 0.63 | 0.59 | 0.58 |

Corr (intercept, time) | NA | NA | −0.61 | −0.59 | −0.58 |

SD Residual | 1.320 | 1.130 | 1.030 | 1.020 | 1.01 |

Pseudo *R*^{2} | | 0.267 | 0.391 | 0.403 | 0.415 |

LL | −593 | −587 | −578 | −569 | −566.8 |

Model comparison | | 2 vs. 1^{a} | 3 vs. 2^{a} | 4 vs. 3^{a} | 5 vs 4^{b} |