Abstract
INTRODUCTION: The efficacy of smoking cessation intervention has been proven with randomized controlled trials. Our study aims to elucidate the effects of the delivery method of smoking cessation advice on the process of stage of changes with transtheorectical model underpinning in a community setting. METHODS: A total of 436 subjects were recruited in a quasi-experimental untreated control design study, with 46 receiving advice from healthcare professionals (HCP group) and 390 in the control group, in 2003, Nantou, Taiwan. A discrete time Markov model was used to quantify the multi-state process of smoking cessation in light of the transtheorectical model. Multiple polytomous logistic regression models were simultaneously applied to different transitions. RESULTS: The estimated forward transition probabilities were higher in the HCP group compared to their counterparts in the control group. On the other hand, the backward transition probabilities were smaller in the HCP group. After adjusting for confounding factors, HCP had a 4.3-fold (95% CI: 2.21-8.46) odds ratio of moving forward from the contemplation stage, and 2.4-fold odds ratio (95% CI: 1.03-4.42) from the preparation stage. Elderly people were more reluctant to change from precontemplation (AOR=0.50; 95% CI: 0.34-0.74) and contemplation (AOR=0.58; 95% CI: 0.44-0.84), but once in the preparation stage, they were more likely to take action (AOR=1.28; 95% CI: 1.01-1.83). For those in the preparation stage, longer smoking years had a negative effect on taking action (AOR=0.74; 95% CI: 0.52-0.99), but cessation advice from others enhanced the likelihood to take action (AOR=1.36; 95% CI: 1.01-1.99). CONCLUSIONS: The direct advice on smoking cessation from healthcare professionals enforced the net forward transition towards smoking cessation, especially the transition from contemplation and preparation. The proposed Markov regression model assessed the net effect of different intervention approaches allowing for the simultaneous consideration of multiple transitions and the effects of other confounders.