Simulation results at significance level with different methods for phenotypic data generated from model (2).

<p>LME-RSI: a linear mixed-effects model with random slope and intercept; LME-RI: a linear mixed-effects model with only a random intercept term; GEE-Robust: GEE with the sandwich covariance estimator; GEE-Naive: GEE with the model-based covariance estimator; Baseline: a linear model at the baseline testing for the main effects of an SNP.