What is the impact of medication, and adjustment for medication, on GWAS effect estimates?
(1) mismatched adjustment percentages/values with the truth; (2) variation in medication effects among patients; (3) associations between such variation in medication effects and the outcome and/or exposure variables; and (4) determination of the optimal adjustment percentage/value, and whether the maximum R2 procedure outlined in the real data application is effective in identifying these optimal adjustment values.