Reactions to Thirdhand Smoke are Associated with Openness to Smoking in Young Never Smoking Children.

To investigate the associations between reactions to thirdhand smoke (THS) and openness to smoking in young children. In a school-based survey in Hong Kong, 4762 Chinese primary school students reported their reactions to THS (one or more of 'pleasant/happy', 'nausea', 'excited', 'heart beat faster', 'relaxed', 'dislike the smell', 'like the smell', 'dizzy', 'coughing/choking', 'eye uncomfortable' and 'none of the above'), smoking status and openness to smoking (lack of a firm intention not to smoke). Factor structure of reactions to THS was investigated with factor scores calculated and categorised. Logistic regression yielded adjusted odds ratio (AOR) of openness to smoking for reactions to THS. Factor analysis yielded two factors including 5 and 4 reactions, which were generally deemed negative and positive, respectively. The proportions of students with factor scores ≥1 for negative and positive reactions were 51.3 and 6.3 %, respectively. In never smokers, openness to smoking was negatively associated with 'dislike the smell' (AOR 0.52, 95 % CI 0.39-0.68), 'coughing/choking' (0.53, 0.38-0.75), 'eye uncomfortable' (0.62, 0.40-0.95) and negative reaction factor score of 2-5 (vs. 0) (0.59, 0.40-0.88), and was positively associated with 'pleasant/happy' (2.80, 1.54-5.09), 'excited' (2.83, 1.17-6.87), 'like the smell' (3.06, 1.49-6.26) and positive reaction factor score of 1-4 (vs. 0) (2.86, 1.83-4.48). In experimental or former smokers, fewer associations reached statistical significance. Negative and positive reactions to THS were negatively and positively associated with openness to smoking, respectively, in young never smoking children.