Table 2. Hierarchicallogistic regression analyses of the association between the smoking and depression: odds ratio (OR) and confidence interval (CI).

Smoking	Univariate model	Model 1	Model 2
Non smoker	1	1	1
Smoker	1.73 (1.50, 1.99)*	1.59 (1.34, 1.88)*	1.27 (1.02, 1.57)*
Cigarette per day
1–2	1.33 (1.04, 1.71)*	1.22 (0.93, 1.62)	1.10 (0.81, 1.50)
3–4	1.06 (0.62, 1.83)	0.88 (0.48, 1.61)	0.92 (0.49, 1.75)
≥5	2.03 (1.71, 2.40)*	1.91 (1.57, 2.34)*	1.48 (1.13, 1.92)*

Notes.

^*p < 0.05.

Model 1: Adjusted for sex, age, type of school, economics home, school record, and satisfaction with school life.

Model 2: Additionally adjusted for self-reported health status, satisfaction with relationship with parents, and drinking experience.