FBAT using the expectation-maximum algorithm. In the case-control samples, a χ2 test was used to examine the association of SNP alleles and genotypes with cocaine-related traits. Odds ratios and their 95% confidence intervals for the allelic associations were computed using logistic regression analysis. Odds ratios were unaffected by adjustment for age and sex. In these analyses, controls were compared with distinct case samples of subjects with CIP and subjects with CD who did not have CIP. Haplotype association analyses were performed in the family samples using HBAT, the haplotype extension routine in the FBAT program,32 and in the case-control samples using haplo.stats.33
