Chat-based instant messaging support integrated with brief interventions for smoking cessation: a community-based, pragmatic, cluster-randomised controlled trial

Abstract

Background Mobile instant messaging apps offer a modern way to deliver personalised smoking cessation support through real-time, interactive messaging (chat). In this trial, we aimed to assess the effect of chat-based instant messaging support integrated with brief interventions on smoking cessation in a cohort of smokers proactively recruited from the community. Methods In this two-arm, pragmatic, cluster-randomised controlled trial, we recruited participants aged 18 years or older who smoked at least one cigarette per day from 68 community sites in Hong Kong, China. Community sites were computer randomised (1:1) to the intervention group, in which participants received chat-based instant messaging support for 3 months, offers of referral to external smoking cessation services, and brief advice, or to the control group, in which participants received brief advice alone. The chat-based intervention included personalised behavioural support and promoted use of smoking cessation services. Masking of participants and the research team was not possible, but outcome assessors were masked to group assignment. The primary outcome was smoking abstinence validated by exhaled carbon monoxide concentrations lower than 4 parts per million and salivary cotinine concentrations lower than 10 ng/mL at 6 months after treatment initiation (3 months after the end of treatment). The primary analysis was by intention to treat and accounted for potential clustering effect by use of generalised estimating equation models. This trial is registered with ClinicalTrials.gov, number NCT03182790. Findings Between June 18 and Sept 30, 2017, 1185 participants were randomly assigned to either the intervention (n=591) or control (n=594) groups. At the 6-month follow-up (77% of participants retained), the proportion of validated abstinence was significantly higher in the intervention group than in the control group (48 [8%] of 591 in intervention vs 30 [5%] of 594 in control group, unadjusted odds ratio 1•68, 95% CI 1•03-2•74; p=0•040). Engagement in the chatbased support in the intervention group was low (17%), but strongly predicted abstinence with or without use of external smoking cessation services. Interpretation Chat-based instant messaging support integrated with brief cessation interventions increased smoking abstinence and could complement existing smoking cessation services. Funding Hong Kong Council on Smoking and Health.

Effects of simple active referrals of different intensities on smoking abstinence and smoking cessation services attendance: a cluster‐randomized clinical trial

“…This is often considered unnecessary in population-based trials of smoking cessation interventions with minimal contact between the investigators and participants [25]. The participation rate in the validation was approximately 51.1%, which was acceptable and comparable to our previous studies [11,15] and trials conducted in similar settings elsewhere [10]. The participation rates were similar among the three study groups, and the relative effect sizes of self-reported and bio-verified abstinence outcomes were homogeneous.…”

“…A significantly higher cumulative rate of the use of a smoking cessation service was observed in the OSR group than in the less intensive TMR and control groups. This, coupled with our observation that the use of a smoking cessation service is associated with increased abstinence at 6 months [15], suggested that the higher 6-month abstinence rate was attributable to the greater use of smoking cessation services in the OSR group than in the control group. However, the TMR group had a higher abstinence rate than the control group, despite a similar rate in the use of smoking cessation services.…”

“…Randomization was performed at the community site level; all participants within the same site received the same intervention. Similar to our previous trials [11,[13][14][15], we were assisted by trained smoke-free ambassadors; namely, undergraduate students and volunteers from non-governmental organizations, to recruit participants and deliver baseline interventions. All ambassadors attended a 1-day workshop and were tested on their knowledge, attitude and practice before participant recruitment.…”

“…This is a three-arm, parallel, cluster-randomized controlled trial wherein participants were randomized to receive an on-site referral (OSR), text messaging referral (TMR), or general cessation advice (control). The trial was nested within a 'Quit to Win' contest for smoking cessation conducted in all 18 districts in Hong Kong [11][12][13][14][15]. The study protocol (Supporting information, Data S1) has been published elsewhere [16] and has been approved by the Institutional Review Board (IRB) of the University of Hong Kong/Hospital Authority Hong Kong West Cluster (UW16-320).…”

“…Similar to our previous trials [11,[13][14][15], all ambassadors were instructed to follow a standardized recruitment script to ensure the accurate delivery of baseline interventions and print-based materials. At each recruitment session, a research assistant provided the necessary supervision and assistance to the ambassadors.…”