Hypothesis tests were conducted with the δ coefficient for the product term testing interaction between Fast Track treatment and genotype. We adjusted for multiple testing using a modified Bonferoni correction according to the procedure described by Nyholt (2004). After accounting for the linkage structure (non-0 correlation) among the ten SNPs, the significance criteria approximating α=0.05 for the European-American and African-American samples were p=0.0056 and p=0.0054, respectively. We conducted a series of post-hoc analyses on SNPs meeting the adjusted significance criterion, including sensitivity analyses and analyses examining the diagnostic specificity of interaction effects. All analyses were conducted using both additive and dominance models. We report coefficient estimates and p-values from the additive model (effects in terms of each additional test allele carried). We report outcome prevalences according to the dominance model (carriers vs. non-carriers of test alleles). All analyses were conducted in SPSS 20.0.
