Non-smokers, smokers, ex-smokers. Three separate problems for health education.
D001519:Behavior; D003657:Decision Making; D004739:England; D006266:Health Education; D006801:Humans; D012380:Role; D012649:Self Concept; D012803:Sick Role; D012907:Smoking; D000074606:Smoking Prevention; D012931:Social Environment