Innovations of the youth quitline for improving smoking cessation among youth smokers in Hong Kong

Abstract

Quitline has been found effective in helping youth smokers quit. However, recruiting youths remains challenging due to their reluctance to seek cessation treatments, proactive outreach and online method are adopted to engage more youths in quitting. Depressive symptoms and electronic-cigarettes (e-cigarettes) may also influence quitting. Understanding the associations of various factors with quitting can help improve quitline services. This thesis examined the associations of recruitment methods, e-cigarettes, and depressive symptoms with quitting by analysing data from the Youth Quitline cohort study conducted during 2015-2022. Mobile ecological momentary assessment (EMA) collected real-time data on smoking status, mental states and situational smoking cues in natural contexts. A pilot randomised controlled trial (RCT) was conducted in May-August 2023 with Youth Quitline to examine the feasibility, acceptability, and effectiveness of EMA-based intervention.

Demographic characteristics, smoking profiles, and depressive symptoms were measured in the Youth Quitline cohort study. Participants in the trial were randomised 1:1:1 to EMA+ (EMA-based peer counselling), EMA (EMA and usual peer counselling), and control (usual peer counselling) groups. Feasibility and acceptability measures were collected. Self-reported 7- and/or 30-day point prevalence of abstinence (PPA) and biochemically validated abstinence were assessed at 3 and/or 6 months. Logistic, linear, and Poisson regressions were used.

Online method recruited more participants with moderate-heavy nicotine dependence (53.2% vs 40.9% vs 27.6%) and depression (51.4% vs 42.5% vs 37.4%) than traditional and outreach (all p<0.01). Outreach recruited fewer participants (28.4%) with intention to quit in 30 days than traditional (41.6%) and online (40.3%) methods (p<0.001). Compared to traditional method, the 6-month validated abstinence was similar in online recruited smokers (aOR 1.03, 95% CI 0.54-1.95) but lower in outreach recruited smokers (aOR 0.34, 95% CI 0.19-0.58). The 6-month validated abstinence (aRR 0.76; 95% CI 0.44–1.31) and self-reported PPA (20.2% vs 21.2%, aRR 0.92, 95% CI 0.68-1.24) was insignificant different among current e-cigarette users and non-users, regardless of sex, age, nicotine dependence, and daily smoking (all p >0.05). Being at risk of depression predicted lower 7-day PPA at 1 (aOR 0.66, 95% CI 0.47–0.93) and 3 months (aOR 0.71, 95% CI 0.52–0.97). Quitting at 1 (aOR 0.40, 95% CI 0.23–0.69), 3 (aOR 0.58, 95% CI 0.37–0.92), and 6 months (aOR 0.44, 95% CI 0.29–0.69) predicted lower odds of at depression risk at 6 months.

For EMA study, the recruitment rate and app download rate was 63.3% and 84.3%. The EMA compliance (completed at least 50% of prompts) rate was 53.1% in EMA+ and 51.9% in EMA groups. The 6-month validated abstinence was insignificant different between EMA+, EMA, and control groups (RR 1.33, 95% CI 0.51, 3.46 and RR 1.67 95% CI 0.68, 4.11).

Using a multipronged recruitment approach can broaden the quitline reach and engage a diverse group of youth smokers. E-cigarettes were not found to aid quitting, and depressive symptoms hindered quitting. EMA-based peer counselling was feasible, acceptable and potentially effective. Tailored interventions utilising mobile technologies that address the unique psychological and social needs of youth smokers are needed for improving cessation outcomes.