Fig 4. Power of stratified GWAMA approaches to identify GxS for unbalanced strata design.

Shown is the power to detect GxS for the same approaches as in Fig 2, but here for unbalanced strata designs with varying proportion of stratum sample sizes, f = n₂/n₁, with stratum 1 being the one with the larger effect. Effect sizes are chosen as in Fig 3 (fixed $R_2^2$ relative to $R_1^2,R_1^2$ as observed for WHRadjBMI loci around STAB1, PPARG, or LYPLAL1): A. qualitative GxS with small $R_1^2$ ($R_1^2=0.014\%,R_2^2=0.014\%$, into opposite direction), B. pure GxS with medium $R_1^2$ ($R_1^2=0.058\%,R_2^2=0\%$), and C. quantitative GxS with large $R_1^2$ ($R_1^2=0.167\%,R_2^2=0.042\%$).