Table 3. CHRN variants and propensity to smoke or chew tobacco.

Adjustment model	n	Fold-change in tobacco use/day (95% CI)	P- Value
Smoking propensity ? (Cigarettes/day)
rs16969968 (CHRNA5)
Base model$	388	1.13 (0.96– 1.34)	0.15
Base+ chewing frequency	388	1.13 (0.95– 1.34)	0.16
Base, among never chewers only	212	1.19 (0.98– 1.44)	0.08
rs578776 (CHRNA3)
Base model$	383	0.99 (0.86– 1.13)	0.87
Base+ chewing frequency	383	0.99 (0.86– 1.13)	0.87
Base, among never chewers only	205	0.95 (0.82– 1.11)	0.54
Propensity to chew tobacco* (Chewing events/day)
rs16969968 (CHRNA5)
Base model$	622	1.13 (1.01– 1.25)	0.03
Base+ smoking frequency	622	1.13 (1.01– 1.26)	0.03
Base, among never smokers only	446	1.19 (1.06– 1.34)	0.003
rs578776 (CHRNA3)
Base model$	613	0.91 (0.84– 0.99)	0.04
Base+ smoking frequency	613	0.91 (0.84– 0.99)	0.04
Base, among never smokers only	435	0.88 (0.81– 0.97)	0.01

^?derived from linear regression of log transformed number of cigarettes smoked per day as outcome, respective CHRN variant as explanatory.

^*derived from linear regression of log transformed number of chewing events per day as outcome, respective CHRN variant as explanatory.

^$Base model included age, sex, center and case-control status.

significant p- values are indicated in bold.