Prior research has not clarified exactly which variants in the gene NR3C1 should be studied (Vandenbergh & Schlomer, 2014). Therefore, we undertook a “gene-wide” association study approach (Dick, 2011). This approach surveys variation throughout a gene and conducts comprehensive testing. Results are then subjected to a statistical correction that accounts for increased risk of false positives arising from multiple testing. We surveyed variation throughout NR3C1 using haplotype tagging analysisvi (Dick, Latendresse, & Riley, 2011). Haplotype tagging identified 10 single-nucleotide polymorphisms (SNPs), which were genotyped in the Fast Track sample (Appendix Figure A1)vii. We used linear probability models to test the intervention-moderating effect of each of these 10 SNPs. To correct for multiple testing, we applied an adjusted Bonferroni correction (Nyholt, 2004). SNPs demonstrating significant gene-by-intervention effects after correction for multiple testing were further examined for stratified main effects in intervention vs. control groups and subjected to sensitivity analyses.
