Table 2.

Mean Difference (95% CI) in Years of Smoking by Race/Ethnicity, NHANES 1999–2012

	N	Unadjusted	Model 1	Model 2	Model 3	Model 4
Overall
White	3707	0.0 (ref)	0.0 (ref)	0.0 (ref)	0.0 (ref)	0.0 (ref)
Black	1127	2.0 (1.1, 3.0)*	1.7 (0.8, 2.6)*	0.7 (−0.1, 1.6)	1.7 (0.9, 2.5)*	2.1 (1.3, 2.9)*
Mexican American	1196	−3.9 (−4.8, −3.0)*	0.3 (−0.8, 1.4)	−1.9 (−2.9, −0.8)*	−1.2 (−2.2, −0.1)*	−0.4 (−1.5, 0.6)
Men
White	2185	0.0 (ref)	0.0 (ref)	0.0 (ref)	0.0 (ref)	0.0 (ref)
Black	656	1.4 (0.1, 2.6)*	1.5 (0.5, 2.6)*	0.6 (−0.4, 1.6)	1.7 (0.8, 2.7)*	2.3 (1.3, 3.3)*
Mexican American	806	−4.0 (−5.2, −2.8)*	0.7 (−0.7, 2.2)	−1.4 (−2.8, −0.1)*	−1.0 (−2.4, 0.3)	−0.2 (−1.6, 1.2)
Women
White	1522	0.0 (ref)	0.0 (ref)	0.0 (ref)	0.0 (ref)	0.0 (ref)
Black	471	2.8 (1.5, 4.1)*	1.9 (0.7, 3.1)*	0.9 (−0.3, 2.1)	1.6 (0.4, 2.8)*	1.9 (0.7, 3.0)*
Mexican American	390	−4.3 (−5.5, −3.0)*	−0.6 (−2.0, 0.8)	−2.6 (−4.2, −1.1)*	−1.5 (−2.9, 0.0)	−0.9 (−2.4, 0.5)

CI = confidence interval; NHANES = National Health and Nutrition Examination Survey. Model 1 adjusted for age, sex (overall only), and country of birth. Model 2 further adjusted for education. Model 3 further adjusted for age at smoking initiation. Model 4 further adjusted for intensity of smoking before quitting (number of cigarettes per day at time of quitting).

*p < .05 for t test.