Table 1 Questions asked and options provided in the survey, and recoding for analysis.

During the past 30 days (one month), on how many days did you smoke cigarettes?

0 day; 1 or 2 days; 3 to 5 days; 6 to 9 days; 10 to 19 days; 20 to 29 days; all 30 days

Any number of days except 0 were coded as current smoker = yes (1)

Do you think boys who smoke cigarettes have more or less friends?

More friends; Less friends; No difference from non-smokers

Re-coded as binary variable, less friends and makes no difference combined and recoded = 0; More friends recoded = 1

Do you think girls who smoke cigarettes have more or less friends?

More friends; Less friends; No difference from non-smokers

Re-coded as binary variable, less friends and makes no difference combined and recoded = 0; More friends recoded = 1

Do you think smoking cigarettes makes girls look more or less attractive

More attractive; Less attractive; Smoking doesn't make a difference

Less attractive and doesn't make a difference recoded = 0; More attractive coded = 1

Do you think smoking cigarettes makes boys look more or less attractive

More attractive; Less attractive; Smoking doesn't make a difference

Less attractive and doesn't make a difference recoded = 0; More attractive coded = 1

Do you think cigarette smoking is harmful to your health?

Definitely not; Probably not; Probably yes; Definitely yes

Definitely yes or probably yes coded = 1; Otherwise 0

Do any of your closest friends smoke cigarettes?

None of them; Some of them; Most of them; all of them

Indicator variables created, with one of the categories as referent

During the past 30 days (one month), when you watched sports events or other programs on TV how often did you see cigarette brand names?

I never watch TV; A lot; Sometimes; Never.

Never and I never watch TV combined and coded=0; A lot or sometimes coded = 1

During the past 30 days (one month), how many advertisements for cigarettes have you seen on billboards?

A lot; A few; None

None = 0; A lot or a few = 1

During the past 30 days (one month), how many advertisements or promotions for cigarettes have you seen in newspapers or magazines?

A lot; A few; None

None = 0; A lot or a few = 1

When you go to sports events, fairs, concerts, community events, or other events, how often do you see anti-smoking information?

A lot; A few; None

None = 0; A lot or a few = 1