20 Sep 2019

The Smoking Cessation Research Team at the School of Nursing and School of Public Health of LKS Faculty of Medicine, The University of Hong Kong (HKUMed), conducted a cluster-randomised controlled trial to examine whether WhatsApp, an instant messaging app, could be used to help people quit smoking. The study found that “WhatsApp chat support”, combined with brief smoking cessation interventions, could increase the chance of quitting by 60% to 90%. The results may have implications for strengthening existing smoking cessation services. The result has just been published in The Lancet Digital Health (link to the publication).

Background

The daily smoking prevalence in Hong Kong was 10% in 2017, which is among the world’s lowest. Although the smoking prevalence in Hong Kong has been falling since 1982, the decline has been levelling off in the past 10 years. Most current adult smokers were hardcore smokers who had never tried to quit and were not interested in quitting. Fewer than 3% current smokers had ever sought help from a local smoking cessation service. Developing interventions that can encourage and help unmotivated smokers quit is important for further reducing the smoking prevalence.

In a focus group interview study of 21 local smokers, the research team found that popular instant messaging apps (e.g., WhatsApp and WeChat) are an acceptable and feasible platform for counsellors to chat with smokers and provide personalised advice to quit smoking. Therefore, the team designed a chat-based WhatsApp intervention for smoking cessation (WhatsApp chat support) and did a cluster-randomised controlled trial to examine its effectiveness.

Research Methodology and Findings

The team conducted a pragmatic cluster-randomised controlled trial at the 8^th “Quit to Win” Smoke-free Community Campaign organised by the Hong Kong Council on Smoking and Health. By using a more relaxed participation criteria, pragmatic randomised trial can recruit a more representative cohort of target recipients and examine the effectiveness of an intervention in real-world settings. Between June and September 2017, the team set up 68 booths throughout Hong Kong and proactively approached and recruited adult smokers at smoking hotspots (where smokers gather and smoke) in the nearby areas. Participants were cluster-randomised into the “intervention group” or “control group”. Participants in the intervention group received brief interventions at baseline plus “WhatsApp chat support” for 3 months. By chatting with participants in the intervention group through WhatsApp, the counsellors learnt about their smoking behaviour, provided personalised, behavioural change theory-based quit advice in real time, and promoted the use of and offered referral to a local smoking cessation service. Participants in the control group only received brief advice to quit and a self-help booklet at baseline. All participants were followed by telephone at 1, 2, 3 and 6 months after joining the study. Participants who self-reported having quit smoking at 3-and 6-month follow-up were invited to do an exhaled carbon monoxide test and a salivary cotinine test to verify their quitting.

The team successfully recruited 1,185 daily cigarette smokers, 591 participants were randomised to the intervention group and 594 to the control group. The participants had a mean age of 41.5 years; most (67.2%) were not motivated to quit at baseline and over half (51.8%) had never tried to quit before. At 3-month follow-up, the chance of verified quitting was 90% higher in the intervention group than in the control group (7.6% [45/591] vs 4.0% [24/594]). At 6-month follow-up, which was 3 months after the end of “WhatsApp chat support”, the chance of verified quitting was still 60% higher in the intervention group than in the control group (8.1% [48/591] vs 5.1% [24/594]). Subgroup analyses revealed that the intervention effect was stronger in smokers who were less motivated to quit at baseline (chance of verified quitting increased by 1.1-fold).

Researchers also analysed the associations of effective engagement in “WhatsApp chat support” (defined by having chatted with a counsellor through WhatsApp) and use of smoking cessation service with quitting in the intervention group. The results showed that, compared to participants who were not engaged in “WhatsApp chat support” and did not use a smoking cessation service (3.3% [14/430]), those who only engaged in “WhatsApp chat support” and those who only used a smoking cessation service had, respectively, 5-fold (20.0% [12/59]) and 4-fold (16.1% [10/62]) increases in chance of verified quitting. Participants who both engaged in “WhatsApp chat support” and used a smoking cessation had 9-fold increase in chance of verified quitting (30.0% [12/40]). The results remained very significant after adjusting for predictors of quitting, including baseline level of nicotine dependence, motivation to quit, and previous quit attempt.

To summarise, the study provided initial evidence that “WhatsApp chat support” could help smokers quit as a stand-alone intervention and in combination with treatment provided by existing smoking cessation services. The team recommend providers of local smoking cessation services to consider adopting “WhatsApp chat support” as a new treatment method for enhancing the reach and effectiveness of smoking cessation treatment. The team is conducting further studies to ascertain and improve the effect of “WhatsApp chat support” on quitting and is planning to adapt the intervention model for treatment for other harmful behaviours (e.g., alcoholism).

About the research team

The study was led by Dr Kelvin Wang Man-ping, Associate Professor, and co-ordinated by Mr Kevin Luk Tzu-tsun, PhD candidate of the School of Nursing, HKUMed. Other members of the team include Professor Lam Tai-hing, Chair Professor of Community Medicine and Sir Robert Kotewall Professor in Public Health of the School of Public Health, HKUMed; Professor Sophia SC Chan, Professor; Dr William HC Li, Associate Professor; Dr Derek YT Cheung, Assistant Professor, and Mr Socrates Y Wu, PhD candidate of the School of Nursing, HKUMed; and Mr Antonio SC Kwong, Chairman, and Ms Vienna WY Lai, Executive Director of Hong Kong Council on Smoking and Health. This study was supported by Hong Kong Council on Smoking and Health.

About the “Quit to Win” Smoke-free Community Campaign

Since 2009, Hong Kong Council on Smoking and Health has organised the “Quit to Win” Smoke-free Community Campaign in collaboration with the School of Nursing and School of Public Health, HKUMed. The campaign disseminates smoke-free messages through district-based promotion activities and media and provides smoking cessation counselling training. The “Quit to Win” contest engages over 1,000 smokers in quitting every year. The contest includes scientific research to design and evaluate different interventions for smoking cessation in order to provide recommendations to improve the existing smoking cessation services in Hong Kong.

HKUMed finds “WhatsApp chat support” could substantially enhance smokers’ quitting rate. (From left) Mr Cheng who successfully quit smoking with the help of HKUMed’s “WhatsApp chat support”; Prof Lam Tai-hing, Dr Kelvin Wang and Ms Vienna Lai from the research team.

Download slides here

Media enquiries

Please contact LKS Faculty of Medicine of The University of Hong Kong by email (medkefa@hku.hk).