Description

This study will separate into two phases. Phase I is a large scale cross-sectional survey of corporations in Hong Kong to examine the employers' knowledge, attitudes and practices in promoting SC in the workplace. Phase II is a 2-arm randomized controlled trial that will be conducted to examine the effectiveness of mobile phone-based intervention combined with company health talk, brief phone counselling and nicotine replacement therapy sampling, for SC in workplaces.

Data analyses Phase I: Descriptive statistics will be used to analyze the (1) profile of the corporations, including the total number of employees and smoking employees; (2) employers/managerial staff's knowledge on smoking; (3) employers/managerial staff's attitudes on smoking cessation; (4) practices of the companies with respect to smoking cessation.

Phase II: Primary outcome is self-reported abstinence in the past 7 days at 6-month follow-up. Secondary outcomes for smoking cessation include self-reported abstinence in the past 7 days at 9- and 12-month follow-ups, the biochemically validated abstinence (defined as exhaled CO level <4ppm and saliva cotinine level ≤30 ng/ml); smoking reduction (50% or above reduction in cigarette consumption compared with baseline. Secondary outcomes for mental health include stress (Perceived Stress Scale-10), depression (Personal Health Questionnaire for Depression), anxiety (Generalized Anxiety Disorder scale) and self-rated health.

Descriptive statistics such as frequency, percentage, and mean will be used to summarize the outcomes and other variables. Chi-square tests and t-tests will be used to compare outcome variables between subgroups. The intention-to-treat (ITT) analysis will be used such that those lost to contact and refused cases at the follow-ups will be treated as no reduction in cigarette consumption nor quitting. Multiple imputations will be used to compute missing data for outcome variables. The association between intervention adherence (e.g., engagement in the IM interaction) and the primary outcome within the participants in the intervention group will be examined. The intervention effect by subgroups will be assessed respectively, including sex, age, education level, company types, previous quit attempts, cigarette dependence, and intention to quit, although the statistical power would be lower due to smaller numbers.