Aim to test the effectiveness of different incentive models for increasing the follow-up response rate in the current smoker subject.

According to the Hong Kong Census and Statistic Department, 10.5% of the Hong Kong population who aged 15 years or above are daily smokers (Thematic Household Survey Report - Report No. 59, 2016). The smoking prevalence was estimated from a thematic household survey that has been conducted every 2 or 3 years. Another population-based survey related to tobacco control is the Tobacco Control Policy-related Survey conducted by the Hong Kong Council on Smoking and Health and the University of Hong Kong. Both surveys were in a cross-sectional design and no follow-up was done. A cohort study with follow-up data could provide more insights for the causal relationship. However, most people are not willing to complete follow-up survey and the response rate is often low (Mellahi, 2016). The low survey response rate could lead to statistically bias in the research funding (Pit, 2014). Therefore, cohort surveys need to provide attractive monetary incentive to the interviewee to increase the response rate (Pit, 2014).

This study aims to assess and compare the 3-month response rate of a follow-up survey due to different financial incentive schemes. The findings will be used for a feasibility assessment of future cohort studies of evaluating tobacco control measures and public opinion, and exploration of appropriate incentive scheme.

Inclusion Criteria:

• Aged 15 or above
• Cantonese or Mandarin speakers

Exclusion Criteria:

• Unable to provide a consent form
• Speak language other than Cantonese and Mandarin

All Hong Kong residents