Fig 5. Recommended stratified GWAMA approaches to detect GxS.

Shown are the recommended approaches to detect GxS when there is no prior hypothesis on the type of GxS (H₀: No GxS) and when there is a prior hypothesis on the type of GxS (H₀: No qualitative GxS; or H₀: No pure GxS; or H₀: No quantitative GxS). The recommendations vary on the degree to which the strata sample sizes differ (f being the proportion of stratum 2 sample size over stratum 1 sample size, f = n₂/n₁ with stratum 1 being the stratum with the larger absolute value of the genetic effect).