Figure 2.

Power and type I error probability (α) for mixed effects analysis, and 40% missingness in sample variances when τ² = 1, ${\tau }_b^2=1$ and τ² = 2, ${\tau }_b^2=2$. The target significance level is 0.05. NM is no missingness, MI is multiple imputation using gamma meta-regression, ME is mean imputation, SGR is single imputation using gamma meta-regression, SLM is single imputation using linear regression based on the log-variance, and CC is complete case analysis.