Genes | R 2 | AIC | P -value |
|---|
SLC6A3
| 0.054, 0.048 | 77.940, 72.719 | 0.025, 0.040 |
SLC6A3 + ANKK1/DRD2
| 0.057, 0.260 | 78.660, 74.262 | 0.045, 0.098 |
SLC6A3 + CYP2A6
| 0.098, 0.087 | 75.327*, 70.761 | 0.009, 0.018 |
- Each analysis was performed for the whole cohort (the left side) and the male subgroup only (the right side). Forward-selection regression began with the effect of the SLC6A3 polymorphism alone. Variables were added one at a time to the model until no remaining variable produced a significant result. SLC6A3: input 1 or 0 for the 10r/10r or other genotype, respectively; ANKK1/DRD2: input 1 for the A2/A2 genotype, 0 for the A1/A2 or A1/A1 genotypes; CYP2A6: input 1 for the *1/*1 genotype, 0 for genotypes including the *4 allele. R2, squared multiple correlation coefficient adjusted for degrees of freedom; AIC, Akaike’s information criterion. *The appropriate model was selected on the basis of minimising AIC.
