Table 4. OR and 95% CI of logistic regression analysis of SHS exposure in the work place.

Categorical variables	In the work place
	Male		Female
	OR	95% CI	OR	95% CI
Social and demographic factors
Age
Younger (19-39 yr)	Ref
Middle-aged (40-59 yr)	0.759†	0.714-0.808	0.789†	0.741-0.839
Older (60 yr and older)	0.492†	0.449-0.539	0.478†	0.431-0.531
Education
≤ Elementary school	Ref
Middle school	1.054	0.945-1.175	1.108*	1.012-1.213
High school	1.024	0.926-1.132	0.855†	0.784-0.933
College or higher	0.739†	0.661-0.825	0.654†	0.589-0.726
Household income yearly
1st quartile (lowest)	Ref
2nd quartile	1.281†	1.162-1.412	1.083	0.999-1.173
3rd quartile	1.264†	1.143-1.399	1.010	0.929-1.098
4th quartile (highest)	1.15†	1.035-1.277	0.863	0.790-1.042
Location of residence
Rural	Ref
Urban	1.134†	1.069-1.203	1.12†	1.060-1.183
Health-related factors
Smoking status
Never smoker	Ref
Ex-smoker	1.037	0.987-1.091	1.262†	1.086-1.468
Drinking
No	Ref
Yes	1.334†	1.250-1.425	1.295†	1.228-1.367
Physical activity
No	Ref
Yes	1.113†	1.059-1.17	1.220†	1.156-1.289
Work-related factors
Employment
Employer and owner-operator	Ref
Paid worker	1.151†	1.081-1.225	0.641†	0.602-0.683
Unpaid family worker	0.874	0.699-1.093	1.045	0.957-1.142
Occupation
Officials or managers	Ref
Professionals	1.037	0.954-1.128	2.24†	2.059-2.437
Service workers	1.511†	1.353-1.687	2.621†	2.395-2.868
Sale workers	1.449†	1.309-1.605	1.715†	1.556-1.89
Skilled agricultural or forestry or fishery	0.353†	0.313-0.398	0.392†	0.344-0.448
Craft and related trades workers, Plant or machine operators and Assemblers	1.82†	1.683-1.967	1.886†	1.668-2.133
Manual laborer	1.495†	1.354-1.652	1.989†	1.799-2.198
Professional soldiers	1.291*	1.037-1.607	1.939	0.653-5.757

OR, odds ratio; 95% CI, 95% confidence interval; SHS, secondhand smoke.

^* P value less than 0.05; ^† P value less than 0.01.