# 重复测量与时间变化：模拟研究方案

数据生成与分析定义：180 simulated individuals with six monthly visits at 0..5, stable binary group and baseline z. Seed230925. Outcome y=2+0.3*time+0.4*group+0.2*time*group+0.25*z+normal subject intercept SD1.3+normal subject slope SD0.35*time+normal measurement error SD1. Fitted linear mixed model y~factor(group)*time+z+(1+time|id), REML with Satterthwaite contrasts at months0 and5. The selected output is the mixed model, not GEE. Educational outcomes in arbitrary units; no clinical observations.

种子与数据生成代码：scripts/validation/ch4-standard-numerics.R、ch4-advanced-numerics.R。

交付：描述性基线、分析纳排记录、模型系数及效应表图、诊断、英文 IMRAD 草稿与摘要。全部数据为程序生成，无临床结论。