Table 1 Variable definitions and assignment criteria

Health literacy

1=“score ≥ 53”;0=“score < 53”

Knowledge of smoking hazards

1=“score = 6”;0=“score < 6”

 Smoking can cause stroke

1=“yes”;0=“no/not sure”

the total score for each question is the score of the respondents’ knowledge of smoking hazards, with a score range of 0–6

 Smoking can cause heart disease

 Smoking can cause lung cancer

 Secondhand smoke can cause heart disease in adults

 Secondhand smoke can cause lung disease in children

 Secondhand smoke can cause lung cancer in adults

Intention to quit smoking

1="Ready to quit smoking within a month/Ready to quit smoking within 12 months/Will quit smoking, but not within 12 months”;0= “Don’t want to quit smoking”

Intensity of intention to quit smoking

1=“Will quit smoking, but not within 12 months”;2=“Ready to quit smoking within 12 months”3= “Ready to quit smoking within a month”