Thai kids who start with e-cigs more likely to go on to add cigs

Kade Patanavanich, Methavee Worawattanakul, and I just published “Longitudinal bidirectional association between youth electronic cigarette use and tobacco cigarette smoking initiation in Thailand” in Tobacco Control. This paper shows that in Thailand, as in richer countries, never-smoking youth who use e-cigarettes are more likely to become smokers than kids who don’t use e-cigarettes. (Kids who start with cigarettes are also more likely to add e-cigarettes.) The only difference between the risk we found and the average risks found in earlier studies done in rich countries is that the risk of going on to cigarettes we found in Thailand was higher. This may reflect the fact that our study was done at a time when the more addictive protonated e-cigs pioneered by Juul dominated the market whereas the earlier studies were mostly done when the market was dominated by older generation e-cigs.

This paper provides important evidence for Thai policy makers to maintain their ban on sales of electronic nicotine deliver devices (which include liquid e-cigs and solid heated tobacco products) despite industry pressure. Our new paper specifically debunks claims by e-cig advocates in Thailand that youth e-cig use does not increase cigarette smoking.

This is a longitudinal study where youth are followed forward in time, so there is not an issue of reverse causality, a criticism popular with e-cig advocates.

Here is the abstract:

Introduction: This study quantifies the longitudinal association between e-cigarette use and subsequent conventional cigarette initiation and vice versa among Thai youths.

Methods: Data from a longitudinal survey of 6045 Thai seventh grade students with baseline in 2019 and the 12-month follow-up in 2020 were analysed using complex survey multivariate logistic regressions to assess whether e-cigarette use was associated with subsequent cigarette smoking (ever, current and dual product users at follow-up) among baseline never smokers.

Results: Consistent with prior findings from other countries, among those who had never smoked cigarettes at baseline, ever e-cigarette users were more likely to try cigarette smoking (adjusted OR 4.44; 95% CI 2.23 to 8.86; p<0.001), or become dual users (adjusted OR 5.31; 95% CI 2.63 to 10.74; p<0.001) 1 year later. Baseline current e-cigarette users were more likely to become ever smokers (adjusted OR 5.37; 95% CI 1.82 to 15.90; p=0.005), current smokers (OR 3.92; 95% CI 1.69 to 9.14; p=0.003) and dual product users (adjusted OR 6.96; 95% CI 1.54 to 31.38; p=0.015) at the 12-month follow-up than non-e-cigarette users. Similarly, among never e-cigarette users at baseline, ever cigarette smoking were more likely to try e-cigarettes (adjusted OR 3.38; 95% CI 1.66 to 6.88; p=0.002), currently use e-cigarettes (adjusted OR 2.75; 95% CI 1.47 to 5.13; p=0.003) and currently use both e-cigarettes and cigarettes (adjusted OR 4.87; 95% CI 2.92 to 8.13; p<0.001) at the follow-up than never smokers. Among never e-cigarette users at baseline, current-cigarette smoking were more likely to try e-cigarettes (adjusted OR 6.21; 95% CI 2.58 to 14.95; p<0.001), currently use e-cigarettes (adjusted OR 2.80; 95% CI 1.27 to 6.14; p=0.014) and currently use both e-cigarettes and cigarettes (adjusted OR 7.70; 95% CI 3.45 to 17.19; p<0.001) at the follow-up than never smokers.

Conclusions: This longitudinal study in Asian low-income and middle-income countries supports the prospective association of youth e-cigarette use with subsequent smoking initiation and youth cigarette use with subsequent e-cigarette initiation that is similar to that observed in high-income Western countries.

The full citation is: Patanavanich R, Worawattanakul M, Glantz S. Longitudinal bidirectional association between youth electronic cigarette use and tobacco cigarette smoking initiation in Thailand. Tob Control. 2022 Sep 14:tobaccocontrol-2022-057491. doi: 10.1136/tc-2022-057491. Epub ahead of print. PMID: 36104174. It is available here.

Published by Stanton Glantz

Stanton Glantz is a retired Professor of Medicine who served on the University of California San Francisco faculty for 45 years. He conducts research on tobacco and cannabis control and cardiovascular disease/

2 thoughts on “Thai kids who start with e-cigs more likely to go on to add cigs

  1. This research seems a little dodgy to me. As we know, there is always a proportion of teens who will experiment and be prone to addictive behaviour. They’ll try everything. Cigarettes, alcohol and now vaping. Surely the obvious conclusion is to encourage the end of tobacco sales and not vaping? What am I missing here?


    1. What you are missing is that we controlled for demographic and behavioral predictors of smoking in our analysis.

      Here are the details, from the paper:

      “Sociodemographic characteristics assessed at baseline included age, sex, academic achievement (grade point average (GPA) on a 0–4 scale), parental education (with vs without college education), social network smoking behaviour21 (parental smoking: any vs none and peer smoking: any vs none), peer approval of smoking (“Do any of your closest friends mind if you smoke?”), living with both parents (yes vs no) and current (past 30 days) alcohol use.

      “We also included mental health status using a total difficulty score of Strengths and Difficulties Questionnaire (SDQ) in the analysis. The SDQ is a 25-question tool which has been used to evaluate mental health status during the past 6 months of young children and adolescents aged 4–16 years.27–29 Each question is scored on a 3-point Likert scale. The SDQ consists of five subscales (emotion, conduct, hyperactivity, peer problems and prosocial).30 The SDQ’s total difficulty scores are sum of the first four subscales with the total score of 40 (10 on each scale), where larger scores correspond to more social, emotional and behavioural difficulties.29 The fifth subscale (prosocial) is generally scored separately where smaller scores correspond to more antisocial behaviour (the total score of 10), so we added prosocial as a separate variable. [citations omitted]”

      All the good studies showing that kids who initiate tobacco use with e-cigs are more likely to go on to smoke cigarettes include similar corrections.


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