Table 3. Summary of logistic regression analysis (major and interaction effects) for prediction of smoking abstinency by nonsmokers (n=380).

Variable	OR	SE	95 % CI	Nagelkerke’s R2
First step of regression				0.10
Study group (ref.: control group)	3.01	0.69	0.78−11.70
Sex (ref.: male)	1.47	0.83	0.29−7.47
Interaction
Study group × sex	1.75	0.95	0.27−11.13
Last step of regression				0.10
Study group (ref.: control group)	2.54	0.56	0.85−7.53
Interaction
Study group × sex	2.56	0.45	1.06−6.19

OR=odds ratio; SE=standard error; CI=confidence interval; ref.=reference group