Table 3.

Smoking initiation among Minnesota Adolescent Community Cohort by clean indoor air policy status ^§

Predictor variables	Adjusted OR (95% CI)‡
Main explanatory variable
No clean indoor air policy	1.08 (1.00 – 1.16)*
Individual level variables
Age in years	1.43 (1.41 – 1.44) *
Cohort (age at baseline)
11	0.64 (0.52 – 0.79) *
12	0.91 (0.77 – 1.08)
13	0.78 (0.66 – 0.92) *
14	0.75 (0.64 – 0.92) *
15	0.65 (0.55 – 0.77) *
16	Reference
Male gender	0.98 (0.88 – 1.08)
Race/ethnicity
Black	0.35 (0.25 – 0.50) *
American Indian	2.98 (1.98– 4.25) *
Asian	0.42 (0.29 – 0.62) *
Hispanic/Latino	0.85 (0.60 – 1.19)
Other race	0.92 (0.64 – 1.33)
White	Reference
Parental smoking at baseline
Mother	1.61 (1.41 – 1.85) *
Father	1.78 (1.56 – 2.03) *
No smoking in the home	0.94 (0.89 – 0.99) *
Number of close friends who smoke
4	5.14 (4.74 – 5.57) *
3	3.40 (3.16 – 3.65) *
2	2.48 (2.35 – 2.62) *
1	1.67 (1.59 – 1.75) *
0	Reference

OR = Odds ratio, CI = Confidence interval

^§Smoking initiation defined as ever smoking at least one cigarette

^‡Adjusted by percentage of population 18 and older, percentage college educated or greater, percentage rural, percentage White race, and median income.

^*p<0.05