Fig. 1
From: The case-only design is a powerful approach to detect interactions but should be used with caution
Quantile–Quantile plot for the case-only and case–control designs. Data were generated under the null with no interaction when there are two main effects [\({\beta }_{G}=\ln(1.2)\) and \({\beta }_{E}=\ln(2)\)]. The MAF for the genetic variant is 0.2 and the frequency of the environmental exposure is 0.1. A total of 1,000,000 replicates were generated. The sample sizes are N = 10,000 cases for both the case-only and case–control designs and additionally for the case–control design there are N = 10,000 controls