Evolution of Tobacco and E-cigarette Experimentation and Use Among French Adolescents Aged 15-16 Years From 2018 to 2020: A Cross-sectional Observational Study

Background We assessed and compared the evolution of tobacco and e-cigarette experimentation and use among French adolescents aged 15-16 years. Methods A Results


Introduction
The rapid development of e-cigarette experimentation and use has been declared a major public health concern by the EU (Tobacco Products Directive 2014/40/EU) [1]. Indeed, vaping could soon become widespread in the population. The practice has been shown to grow rapidly among youth [2][3][4], with data from the US indicating a high prevalence among non-smoking adolescents [5]. More worrying still, a meta-analysis of UK studies found the risk of smoking traditional cigarettes to be vastly increased in adolescents who use e-cigarettes [6]. In French adolescents aged 17 years, however, e-cigarette use has been shown to remain moderate and to be mainly initiated by daily smokers [7].
In fact, a major scienti c controversy is currently ongoing based on contrasting perceptions of ecigarettes. On one side of the debate are those who consider that vaping helps smokers reduce or quit smoking. Some authors note that e-cigarettes are perceived as a smoking cessation tool [3], with smokers themselves highlighting their therapeutic potential [8,9]. Three Cochrane reviews nd that nicotine e-cigarettes are more effective than nicotine substitutes in helping young adult smokers wean themselves off smoking [10][11][12]. In the UK, the 2021 Public Health England report [13] concludes that e-cigarettes are an effective aid to smoking cessation and reduction, while Levy et al. [14] suggest that the observed reduction in smoking prevalence in the adult population is explained by the increased use of nicotine ecigarettes. In France, Legleye et al. [15] report a 42% reduction in the risk of becoming a daily smoker in adolescents aged 17-18.5 years who experimented with e-cigarettes rst, and Chyderiotis et al. [16] [15] con rm the absence of an increased risk of progression from vaping to daily smoking among adolescents aged 17 years.
On the other side of the debate are those who view vaping as a gateway to smoking. A detailed report of the National Academies of Sciences, Engineering and Medicine [17][18][19] describes e-cigarettes as a "gateway" object and concludes that they are associated with the risk of progression to smoking, especially when they contain nicotine. Likewise, a meta-analysis of 30 longitudinal studies from 22 different cohorts states that e-cigarette use can be considered a predictor of subsequent smoking [20].
Several other studies [21][22][23] highlight an association between e-cigarette use and subsequent smoking initiation among adolescents and young adults. More generally, Brown et al. [24] and Kinnunen et al. [25] recommend caution over nicotine e-cigarettes, arguing that nicotine exposure can cause dependence and, consequently, the progression to smoking among young vapers. These various studies, however, should be interpreted with caution, as the factors underpinning the progression from e-cigarette experimentation to daily smoking are not yet clearly understood and must be clari ed in future studies.
The contrasting perceptions of e-cigarettes have raised concerns among public health agencies about the uncertain impact of vaping in the general population, and especially in adolescents [7]. Indeed, adolescence is a particularly sensitive age marked by experimentation with psychoactive products [26], with some studies showing that the majority of adult daily smokers began smoking at that age [27]. Uncertainties about the impact of vaping are compounded by con icting data on the evolution of vaping and smoking behaviour: while some studies report that adolescent and young adult vapers tend to progress to smoking over time [28], others observe a decrease in smoking prevalence and attribute it to the increase in e-cigarette use [14,26]. In fact, the mechanisms behind these trends are not well understood, as few studies [8,29,30] have explored the expectations and motivations of youth who experiment and use e-cigarettes and/or tobacco products. In France, cross-sectional studies data on vaping and smoking mainly rely on data published by public research organisations like Santé Publique France and the O ce Français des Drogues et des Toxicomanies (OFDT) [31]. These organisations conduct yearly surveys, including the ESCAPAD and Baromètre Santé surveys, to trace the evolution of e-cigarette and tobacco experimentation and use in the general population. According to the 2014-2019 Baromètre Santé survey [32], the prevalence of e-cigarette experimentation in adults aged 18-75 years was 34.4% in 2019, a gure very close to that reported for 2018 (34.7%) [33] but lower than that reported for 2017 (41.7%) [34]. Moreover, in 2019, the prevalence of current vaping was 5.7% and that of daily vaping was 4.4% [32]. These gures are higher than those reported for the year 2017 (3.8% for current vaping and 2.7% for daily vaping) [34] but fairly close to those reported for the year 2018 (5.3% for current vaping and 3.8% for daily vaping) [35], suggesting a stabilization of current and daily vaping in the general population. According to the 2020 Baromètre Santé survey [36], the prevalence of e-cigarette experimentation in adults aged 18-75 years was 37.4% in 2020, a gure slightly higher than those reported for the years 2019 (34.4%) [32], 2018 (34,7%) [33] and 2017 (41.7%) [34]. Moreover, in 2020, the prevalence of current vaping was 5.4% and that of daily vaping was 4.3% [36]. These gures are higher than those reported for the year 2017 (3.8% for current vaping and 2.7% for daily vaping) [34] but fairly close to those reported for the years 2018 (5.3% for current vaping and 3.8% for daily vaping) [33] and 2019 (5.7% for current vaping and 4.4% for daily vaping) [32], suggesting a stabilization of current and daily vaping in the general population. As regards tobacco use, the 2020 Baromètre Santé survey reports a prevalence of current smoking of 31.8% in adults aged 18-75 years in 2020 [36]. This gure is similar to those reported for the years 2017 (31.9%) [34] and 2018 (32.0%) [33] but represents a decrease of 2.5 points compared to 2014 (34.3%) [32]. Lastly, a signi cant and continuous decline is observed in the prevalence of daily smoking between 2014 and 2019: from 28.5% in 2014 to 26.9% in 2017 [34], 25.4% in 2018 [33] and 24.0% in 2019 [32]. While the prevalence of daily smoking increased slightly in 2020 (25.5%) [36], the difference is too small to contradict this downward trend.
Smoking and vaping behaviour among French adolescents appear to follow similar trends. Thus, according to the 2017 French ESCAPAD survey, the 2014-2017 period saw a sharp decline in the prevalence of tobacco experimentation (from 68.4% in 2014 to 59.0% in 2017) and that of daily smoking (from 32.4% in 2014 to 25.1% in 2017) in adolescents aged 17 years [37]. More than one out of two (52.4%) adolescents aged 17 years experimented with e-cigarettes in 2017, a level similar to that reported in 2014 (53.3%) [7]. Moreover, in 2017, the prevalence of occasional vaping was 34.9% in this population while daily vaping was almost non-existent (1.9%) [7]. Lastly, monthly vaping decreased by ve points between 2014 and 2017 (from 22.1% to 16.8%) [7].
It should be noted, however, that published data on smoking and vaping in France mainly concern adults aged 18-75 years or adolescents aged 17 years. The few available data on adolescents aged 15-16 years are often incomplete or outdated. While the Health Behaviour in School-Aged Children (HBSC) and the European School Survey Project on School and Other Drugs (ESPAD) do publish data on this particular age group, these four-yearly surveys mainly consist of overviews of national trends in Europe and of international comparisons of data on tobacco and e-cigarette experimentation and use. As such, they provide global and partial data that do not allow for cross-sectional studies or comparisons of smoking and vaping behaviour among adolescents aged 15-16 years in France.
For public health authorities to make fully informed decisions, it is crucial to better understand both the relationship between smoking and vaping at the pivotal age of 15-16 years and the motivations of adolescents for tobacco and e-cigarette experimentation and use. With a view to reinforcing French observational systems, we conducted a cross-sectional study to complement national data with regional data on smoking and vaping behaviour in the speci c population of adolescents aged 15-16 years. Our main objective was to assess and compare the evolution of tobacco and e-cigarette experimentation and use among thousands of Year 11 pupils attending public secondary school in the Loire department. The point was to closely examine the evolution of smoking and vaping behaviour at the speci c age of 15-16 years. Our secondary objective was to identify the motivations of French adolescents for vaping and smoking and to describe the characteristics of their preferred e-liquids (nicotine content, avour). Data was collected using self-administered questionnaires drawn up by a multidisciplinary team composed of a tobacco specialist, scienti c mediators specialised in adolescence, a researcher in public health and educational sciences as well as aerosol experts and toxicologists specialised in smoking and vaping. Adolescents were asked to answer a number of questions on their experimentation and use of tobacco and e-cigarettes allowing to determine their vaping or smoking status as previously described in Denis-Vatant et al. [26] study. Preliminary reliability and validity tests were conducted with some of the adolescents during the design phase of the questionnaires to ensure proper understanding of the questions.

Methods
The 2018 questionnaire was completed in paper format and the 2019 and 2020 questionnaires were recorded online on the Google Forms platform. The questionnaires were mainly composed of closedended questions, with some semi-open-ended questions on the e-liquid avours used, etc., and with an "Other" question for respondents to add any comments they wished. The data collected via the questionnaires met the con dentiality and anonymity requirements of the National Commission for Information Technology and Liberties (CNIL). They were divided into four main categories: 1. Basic demographic characteristics of study participants: sex and age. Note that age was not recorded in the generated database in order to guarantee the anonymity of adolescents; 2. Experimentation and use of tobacco products, as determined for each year of the study via the question: "Have you ever tried/used tobacco products?" Respondents were asked to specify their preferred types of tobacco products, the duration and frequency of their smoking habit; 3. Experimentation and use of vaping products, as determined for each year of the study via the question: "Have you ever tried/used vaping products?" Respondents were asked to specify their preferred types of vaping products, the avour and nicotine content of the e-liquids they used, the duration and frequency of their vaping habit; 4. Motivations for experimenting with vaping and/or tobacco products ("Why did you start smoking or vaping?") and motivations for using vaping and/or tobacco products ("Why do you like smoking or vaping?"); The questionnaire was proposed to the adolescents by the school nurse of each high school included in the studies with the support of the National Education of the Loire. The adolescents completed the questionnaire under the guidance of the school nurse or, in his or her absence, of a teacher. The questionnaire was administered from January to July of each year, at a date and time decided in consultation with the school principal.
A protocol for administering the questionnaire was established to ensure that the students felt con dent in responding. The objectives of the study were clearly explained both to the adolescents and to the nurses who were to help them complete the questionnaire. During questionnaire completion, the adolescents were seated alone at a desk to guarantee anonymity, to facilitate reading and to ensure that the answers given were personal. The maximum time for completing the questionnaire was 15 minutes. The topics covered were designed to t within this time limit. They were told that they could speak to the school nurse if they had any questions about lling the questionnaire.
The analysis consisted in assessing and comparing the evolution of tobacco and e-cigarette experimentation and use from 2018 to 2020. Speci cally, we sought to determine whether the prevalence of vaping and smoking increased, decreased or remained stable over the study period. The motivations of adolescents for vaping and smoking and their e-liquid preferences were also analysed, as was the evolution of these motivations and preferences over time. Questionnaires were processed anonymously using Excel® software. Statistical analyses were carried out using IBM SPSS Statistics 21® software. Percentages were compared in univariate analysis using the Chi-square test. Averages were compared using an analysis of variance or the non-parametric Kruskal-Wallis test, as appropriate. Pearson's correlation coe cient was calculated to determine the association between quantitative variables.  (Table 1).   1).
Evolution of tobacco experimentation and use by sex Fewer girls than boys reported having experimented with at least one tobacco product (Fig. 2). Approximately one in four girls and one in three boys reported being current smokers. The prevalence of occasional smoking was lower in girls than in boys as was that of daily smoking. Over the study period, the prevalence of tobacco experimentation decreased slightly and gradually in girls from 40.24% in 2018 to 39.54% in 2019 and 37.90% in 2020. In boys, the prevalence of tobacco experimentation remained fairly stable between 2018 (42.17%) and 2020 (42.20%), despite a three-point increase in 2019 (45.34%). The prevalence of occasional smoking decreased slightly in boys from 21.08% in 2018 to 17.38% in 2020; however, it increased in girls from 13.01% in 2018 to 16.46% in 2020. The prevalence of daily smoking fell slightly in both sexes, with a lower prevalence in girls (7.85%) than in boys (11.59%) in 2020 (Fig. 2).
Evolution of e-cigarette experimentation and use Overall, 44.92% (n=3,577) of adolescents reported having experimented with e-cigarettes. Moreover, 25.84% (n=1,977) reported being current vapers. The prevalence of occasional vaping was 20.44% (n=1,592) and that of daily vaping was 5.40% (n=385). The prevalence of use and experimentation of vaping products for the 7,883 adolescents included in the study between 2018 and 2020 is shown in the Table 2. However, the prevalence of daily vaping increased signi cantly from 3.50% in 2018 to 5.13% in 2020 (Fig. 3).
Evolution of e-cigarette experimentation and use by sex Fewer girls than boys reported having experimented with vaping products (Fig. 4) (Fig. 4).

Discussion
In France, a sharp decline in smoking prevalence has been observed among adults [36] and adolescents aged 17 years since 2014. In this context, our study aimed to assess and compare the evolution of smoking and vaping behaviour among French adolescents aged 15-16 years. Speci cally, we sought to determine whether the prevalence of tobacco and e-cigarette experimentation and use increased, decreased or remained stable among Year 11 pupils attending public secondary school in the Loire department between 2018 and 2020.
On the one hand, we can compare the prevalence of tobacco use and experimentation obtained in our study to some results described in the literature. In our sample of adolescents aged 15-16 years, the average prevalence of tobacco experimentation over the study period was 41.67%. This gure is almost identical to the European average (41%) and slightly lower than the French average (45%) reported in the 2019 ESPAD report for adolescents of the same age (15-16 years) [38]. The average prevalence of current smoking was 27.51%, which is nearly identical to the average prevalence reported by the OFDT (27.58%) for all French departments for the year 2021 [31] but lower than the European (30%) and French (34%) averages reported in the 2019 ESPAD report [38]. The average prevalence of daily smoking (10.24%) was very close to the European average (10.0%) and slightly lower than the French average (12%), while that of occasional smoking (17.27%) was lower than both the European (20%) and French (22%) averages [38]. Between 2018 and 2020, a continuous decline was observed in tobacco experimentation in our sample. A similar downwards trend was observed in the study by Chyderiotis et al. [16] and in the 2017 ESCAPAD survey [37] for adolescents aged 17 years. Likewise, the prevalence of daily smoking decreased in our sample, which is perfectly consistent with the results of the 2015 and 2019 ESPAD reports for French adolescents aged 15-16 years [38,39]. This decline is also in line with the ndings of the 2017 [34] and 2018 Baromètre Santé surveys [40] for the adult population and those of the 2017 ESCAPAD survey [41]. In the US, the study by Jarvis et al. [4] observed a similar decrease (20.4%) in smoking prevalence among adolescents (from 28.5% in 1999 to 8.1% in 2018), a trend that was associated with the increased market availability of e-cigarettes in the study by Sokol et al. [5].
On the other hand, we can compare the prevalence of vaping use and experimentation obtained in our study to some results described in the literature. The average prevalence of e-cigarette experimentation over the study period was 44.92%. This gure is higher than the European average (40%) and almost identical to the French average (46%) reported in the 2019 ESPAD report for adolescents of the same age [38]. By contrast, the average prevalence of daily vaping was low at 5.40%. The prevalence of ecigarette experimentation in our sample decreased from 50.28% to 41.25% between 2018 and 2020. However, if we compare the prevalence of e-cigarette experimentation for the year 2020 with that reported in the 2015 ESPAD report (35.1%) [39], we observe a considerable increase in this indicator over a period of 5 years. Conversely, the prevalence reported in the 2018 EnCLASS report (52.1%) [42] suggests a decrease in this indicator between 2018 and 2020. It should be noted that in the study by Hammond et al. [43], the prevalence of e-cigarette experimentation increased from 29.3% in 2017 to 40.6% in 2019 among adolescents aged 16-19 years. Over the same period, the study by Jarvis et al. [4] observed a statistically signi cant increase of 15.8% (from 11.7% to 27.5%) in the prevalence of past-30-day ecigarette use among high school students in the US. In our sample of French adolescents, there was a moderate increase in daily vaping (from 3.50% in 2018 to 5.13% in 2020), but this nding needs to be con rmed in future studies.
Over the study period, the prevalence of current smoking was higher in boys than in girls, as was that of current vaping. These ndings are in line with published data showing a male predominance in the prevalence of smoking and vaping in adolescents, young adults and the general population in France and beyond [26,41].
The prevalence of e-cigarette experimentation (44.92%) was higher than that of tobacco experimentation (41.67%) over the study period. This is consistent with French and international studies which show an increase in vaping prevalence and a simultaneous decrease in smoking prevalence in both the adolescent and adult populations. Thus, a meta-analysis of French studies found a simultaneous increase in ecigarette use (from 10.0% to 39.0%) and decrease in tobacco use among lower secondary school pupils (from 15.3% to 10.9%) and higher secondary school pupils (from 38.3% to 33.5%) over the 2012-2014 period [44,45]. Similarly, in the study by Walker et al. [2], all measures of e-cigarette use increased and all measures of tobacco use decreased or remained stable over the 2014-2019 period among New Zealand youth aged 14-15 years. Lastly, in the UK, the substantial reduction in smoking prevalence in the adult population was found to coincide with a rise in e-cigarette use between 2012 and 2019 [14]. The upward trend in e-cigarette experimentation and use may be partly explained by the gradual progression from smoking to vaping in the general population, a shift in behaviour actually recommended by bodies such as Public Health England and the French National Academy of Medicine. Note that our results can be view to be quite consistent with studies suggesting that e-cigarette use is increasingly dissociated from tobacco use among adolescents [16].
The secondary objective of our study was to determine the motivations for e-cigarette and tobacco experimentation and use among French adolescents aged 15-16 years. Curiosity was found to be the primary motivation for e-cigarette and tobacco experimentation (36.98% and 34.88%, respectively), which is consistent with earlier studies on the topic [8,[46][47][48]. Motivations for using tobacco included "to blow smoke" (16.60%) and "for the taste" (10.78%) and those for using e-cigarettes were primarily "to make vapour clouds" (11.53%) and "the variety of avours" (12.02%), re ecting the playful aspect of vaping and smoking [47,48]. Nearly one in ve adolescents (19.32%) said that they smoked to "relax." Furthermore, almost one in six reported smoking to "be with friends" (16.04%). The latter nding con rms the in uence of peers on the decision to use psychoactive products [49] and highlights the need for studies to identify the factors that lead adolescents to resist peer pressure with regards to vaping or smoking. Finally, very few adolescents (4.36%) reported using e-cigarettes "to reduce or quit smoking," in line with studies showing that the majority of adolescents vape for recreational rather than smoking cessation purposes [13,28,49]. This nding nevertheless contrasts with those of the 2021 Eurobarometer survey [50] according to which the majority of adults initiate vaping in order to curb their tobacco consumption. Other studies have shown that motivations for vaping and smoking vary according to age [8,50], raising questions about the formation of consumption habits among adolescents. Future studies should explore the expectations of adolescents to shed light on their motivations for e-cigarette and tobacco experimentation and use. A better understanding of these expectations and motivations would help to develop educational intervention strategies that effectively combat early smoking in young adolescents, thereby preventing adult smoking.
The nicotine content and avour of the e-liquids used were also investigated. Our results show that these did not vary over the study period. Most adolescent vapers did not know the nicotine content of the eliquids they used. Those who did (77.94% of adolescents who answered the question on the nicotine content of their e-liquids) reported contents ranging from 0 to 16 mg/ml: the majority (16.47%) used nicotine-free e-liquids, while 0.34% and 2.69% reported nicotine contents of 16 mg/ml and 12 mg/ml, respectively. This nding suggests that the use of nicotine e-cigarettes can be quite marginal among French adolescents aged 15-16 years, which could partly explain why we found no increased risk of progression from vaping to smoked tobacco. In line with this, some US studies [51][52][53] have shown that adolescents who use nicotine-free e-cigarettes are less likely to become daily smokers than those who use nicotine e-cigarettes. Future studies are needed to understand the relationship between the nicotine content of e-liquids used and the progression from vaping to daily smoking among young adolescents.
The most commonly used e-liquid avours in our study population were fruit and other sweet avours (41.73% of adolescents who answered the question on e-liquid avours). This nding is comparable to the European average (48.00%) reported in the 2021 Eurobarometer survey [54]; it is also consistent with studies showing that the appeal of e-cigarettes among young adolescents is associated with the use of sweet-avoured e-liquids [43,54,55]. Adolescents in our study reported preferring mint-avoured e-liquids (15.70% of adolescents who answered the question on e-liquid avours) to tobacco-avoured ones (6.38% of adolescents who answered this question), which could partly explain why the increase in daily vaping prevalence was not accompanied by a rise in daily smoking prevalence in this population. Interestingly, in the study by Friedman et al. [28], vaping non-tobacco-avoured e-liquids was associated with increased smoking cessation in young adults (18-24 years) and was not associated with increased smoking initiation in adolescents (12-17 years). The relationship between the use of tobacco-avoured eliquids and smoking initiation among adolescents should be explored in future studies.
In our study, approximately one in ve (19.76%) adolescents were dual users of vaping and smoked tobacco products. The exclusive use of either type of products was less frequent, as only 7.90% of adolescents were 'non-vapers and smokers' and 6.15% were 'vapers and non-smokers.' These results are consistent with other French studies conducted among adolescents aged 17 years [7] and with studies from the UK [6]. Between 2018 and 2020, the proportion of "non-vapers and non-smokers" increased from 64.85% to 67.81%, while that of "vapers and non-smokers" remained stable with a slight decrease from 6.30% to 5.89%. Our analysis could not provide reliable results on the proportion of "non-vapers and smokers" who became "vapers and non-smokers" or "non-vapers and non-smokers". However, we did nd that 2-3% of "non-vapers and smokers" seems to progress to the dual use of vaping and smoked tobacco products. This progression may be explained by the fact that exclusive smokers initiate vaping with the intent to reduce or quit smoking in the future. In this regard, the study by 2021 Eurobarometer survey [54]found dual users to be more likely to attempt to quit smoking than exclusive smokers. Yet, the progression from exclusive tobacco use to dual use could also be explained by a loss of interest in smoking and a concomitant desire to adopt exclusive vaping. The motivations for this progression have so far been studied by means of quantitative approaches [56,57] and should be clari ed in future studies using qualitative methods.
Our most relevant nding for public health was the temporal coincidence between an increase in the prevalence of daily vaping and a decrease in that of daily smoking. This nding may be explained by the fact that adolescents who rst experiment with e-cigarettes are more likely not to initiate smoking or to delay their entry into smoking. Thus, the study by Chyderiotis et al. [7] found that French adolescents aged 17 years who initially experiment with e-cigarettes have a very low risk of becoming daily smokers.
Likewise, in the study by Friedman et al. [28], adolescent dual users who had experimented with e-cigarettes rst were less likely to become daily smokers than those who had experimented with tobacco rst. In the study by Legleye et al. [15], experimenting with e-cigarettes before tobacco cigarettes was associated with a 42% reduction in the risk of daily smoking among youth aged 18 to 21 years. Kalhoran et al. [58] found early e-cigarette use to be associated with higher odds of prolonged smoking abstinence, suggesting that e-cigarettes play a role in delaying smoking initiation [59]. Lastly, the study by Coleman et al. [60], conducted in the same sample of US adults, noted that dual users who had initially experimented with e-cigarettes were more likely to quit smoking than those who had initially experimented with tobacco. Future studies are needed to determine the association between vaping initiation and smoking prevalence at the speci c age of 15-16 years.

Study limitations
Our study has several limitations. The use of cross-sectional and descriptive data made it impossible to perform a prospective analysis. However, our research team is currently conducting longitudinal cohort studies in France to explore the temporal evolution of vaping and smoking behaviour (including smoking cessation) between the ages of 15 and 18 years and to determine the relationship between e-cigarette use and tobacco use during adolescence. Furthermore, since our sample was limited to adolescents aged 15-16 years in the Loire department, our ndings cannot be directly extrapolated to other populations. Lastly, although the nicotine content and avour of the e-liquids used appear to be important indicators, we did not evaluate the link between these preferences and the expectations and motivations of adolescents.
Future studies should examine whether adolescents who use nicotine e-liquids are more likely than those who use nicotine-free e-liquids to become daily smokers. Studies are also needed to determine the factors associated with successful or unsuccessful attempts at smoking cessation, with the duration of smoking cessation or abstinence, with occasional smoking relapse, and with resistance to relapse.

Conclusion
Our study shows that e-cigarette experimentation is signi cantly more prevalent than tobacco experimentation among French adolescents aged 15-16 years. Between 2018 and 2020 clear increase is observed in the prevalence of daily vaping. Their motivations for experimenting with e-cigarettes seems to be mainly associated with recreational leisure, much less so with the desire to reduce or quit smoking.
No increase was observed in the progression from vaping to smoking in our sample. French adolescent vapers frequently use e-liquids with little or no nicotine or with fruit or sweet avours. Besides, some "nonvapers and smokers" seems to switch to dual use, maybe with the likely intention to reduce or quit smoking. Given the increase in the proportion of "non-vapers and non-smokers" and the stabilization of ecigarette use, the health situation of French adolescents aged 15-16 years can be said to have globally improved between 2018 and 2020.
Declarations Figure 1 Evolution of tobacco experimentation and use among French adolescents aged 15-16 years from 2018 to 2020