Abstract
Although a few countries have banned flavored cigarettes (except menthol), flavors in most tobacco products remain unregulated across the globe. We conducted a systematic review of qualitative studies examining perceptions of and experiences with flavored non-menthol tobacco products. Of 20 studies on flavored tobacco products included in our qualitative systematic review, 10 examined hookah, six examined e-cigarettes, two examined little cigars and cigarillos (LCCs), and three examined other tobacco products, including cigarettes. The majority of studies, regardless of product type, reported positive perceptions of flavored tobacco products, particularly among young adults and adolescents. In six studies that assessed perceptions of harm (including hookah, LCCs, and other flavored tobacco products), participants believed flavored tobacco products to be less harmful than cigarettes. In studies that examined the role of flavors in experimentation and/or initiation (including three studies on e-cigarettes, one hookah study and one LCC study), participants mentioned flavors as specifically leading to their experimentation and/or initiation of flavored tobacco products. Given that many countries have not yet banned flavors in tobacco products, these findings add to existing research on why individuals use flavored tobacco products and how they perceive harm in flavored tobacco products, providing further support for banning non-menthol flavors in most tobacco products.
Keywords: other tobacco products, tobacco control, flavored tobacco products, regulation
1. Introduction
Flavored tobacco product use among youth and young adults is high, with prevalence rates for current use (i.e., past 30 days) of any flavored tobacco product ranging from 12% among youth to 18.5% among young adults in the United States (U.S.) [1,2]. When examined by product type for young adults, use of any flavored tobacco product ranged from 3% for cigarettes (excluding menthol), to 13% for e-cigarettes, 35% for little cigars/cigarillos or bidis, and 50% for hookah. Additionally, many adolescents initiate tobacco use with flavored products [3], and flavors are one of the main reasons why youth continue to use tobacco products [3]. The 2009 Family Smoking Prevention and Tobacco Control Act authorized the U.S. Food and Drug Administration (FDA) to ban cigarettes with characterizing flavors (except for menthol) [4], but flavors in other non-cigarette tobacco products remain legal [5]. While other countries have also banned flavors in cigarettes (e.g., countries in the European Union), most countries have not enacted such bans, with very few regulating flavors in non-cigarette tobacco products [6,7].
Moreover, while comprehensive reviews have examined the public health impact of menthol tobacco products [8,9,10,11,12,13], only two systematic reviews have examined non-menthol flavored tobacco products. Feirman, et al., examined the use of and attitudes towards non-menthol flavored tobacco products in quantitative (n = 26) and qualitative (n = 6) studies published in the U.S., prior to September 2013 [14]. Huang et al. examined quantitative data (n = 40) on the role of flavors on attitudes, perceptions, intentions, initiation, and cessation of non-menthol flavored tobacco products in U.S. and non-U.S. studies published through April 2016 [15]. Qualitative research serves a complementary yet separate purpose from quantitative research; researchers often use qualitative data to gain a better understanding of the context of a problem, describe complex relationships, and explore new topics [16]. To extend these previous two reviews and further explore individuals’ perceptions of and experiences with flavored tobacco products—specifically why individuals use flavored tobacco products and how they perceive them—we conducted a systematic review of qualitative studies of non-menthol flavored tobacco products through April 2016, including international and more recent qualitative studies not previously reported [14].
2. Materials and Methods
2.1. Inclusion/Exclusion Criteria
Studies that included populations of any age, race, sex, ethnicity, or country and described individuals’ experiences with or perceptions toward non-menthol flavored tobacco products were included. We excluded articles that were not qualitative; were not English-language; were not peer-reviewed; did not contain original data about flavored tobacco products; did not address the specific impact of flavors on tobacco product perceptions and use behaviors; or limited findings to menthol flavored tobacco products only.
2.2. Data Sources and Study Selection
Four databases (PuBMed, Embase, PsycINFO, CINAHL) were used for our search. One author (Hannah M. Baker) searched all of the databases using cognates of “tobacco products” and “flavor” and two authors (Clare Meernik and Hannah M. Baker) conducted a manual search of the reference lists in each included article (see Figure 1). Searches were conducted in three waves: March 2015, September 2015, and April 2016. There were no date restrictions regarding when articles were published. After duplicates were removed, a total of 1688 articles were found. After reviewing titles and abstracts, 138 full-text articles were assessed for eligibility. A total of 20 articles were included in the final analysis. For a full description of our search strategy and study selection, please refer to Huang et al. [15].
Of the 20 studies included, only two were included in any previous review of use of and attitudes toward flavored tobacco products in the United States; 18 studies were not included in any prior flavor systematic reviews. We excluded four qualitative articles from Feirman et al.’s review since they did not specifically address the impact of flavors on perceptions or behavioral outcomes (n = 3) or the article type was a dissertation (not a peer reviewed study) (n = 1).
2.3. Data Extraction
Two authors (Clare Meernik and Hannah M. Baker) independently extracted data, which included study aim, type of flavored tobacco product, characteristics of study populations and study design, and main results and findings related to the impact of flavors in tobacco products. As findings may differ by type of flavored tobacco product, we synthesized results by type of product. We used the validated Quality Assessment Tool (QATSDD) to assess the quality of studies, [17]. The tool includes 14 criteria that apply to qualitative studies (e.g., explicit theoretical framework; description of procedure for data collection; assessment of reliability of analytic process). Two authors (Clare Meernik and Hannah M. Baker) rated each study on a 4-point scale ranging from “0 = did not address criteria at all” to “3 = completely addressed criteria”. Scores were then summed (range 0–42), with higher scores indicating higher quality. Although we did not use these criteria to rank or exclude studies, they provided information which we used in interpreting findings.
3. Results
3.1. Study Characteristics
Half of the 20 studies were conducted in the U.S. (n = 10); the remaining studies were conducted in Scotland, the United Kingdom (UK), the Middle East, Canada, and Malaysia (see Table 1). All of the studies were published in 2009 or after. Half of the studies used one-on-one interviews to collect data (n = 9), while the remainder used focus groups (n = 8) or a combination of focus groups and one-on-one interviews (n = 3). The majority of study participants were young adults between the ages of 18–30, although four studies included adolescents and four studies included adults above the age of 30. In addition, studies included mainly users of tobacco products (n = 11) or both users and non-users of tobacco products (n = 8). Quality scores for included studies ranged from 15 to 38, with a mean quality score of 27.6 (Standard Deviation: 5.9) and a median score of 27.
Table 1.
Study Characteristic | n or Mean (SD) |
---|---|
Location of study | |
U.S. studies | 10 |
Non-U.S. studies | 10 |
Year of publication | |
Between 2009 and 2012 | 6 |
Between 2013 and 2016 | 14 |
Methodology used | |
Focus groups | 8 |
One-on-one interviews | 9 |
Both | 3 |
Age of participants 1 | |
Adolescents (<18) | 5 |
Young adults (18–30) | 16 |
Adults (18+) | 4 |
Tobacco Use Status of Participants | |
Users | 11 |
Non-users | 0 |
Both users and non-users | 8 |
Unspecified | 1 |
Cigarette | 1 |
E-cigarette | 6 |
Hookah, waterpipe | 10 |
Little cigar, cigarillo, cigar | 2 |
Various non-cigarette products | 2 |
Sample size | |
Greater than or equal to 50 participants | 12 |
Less than 50 participants | 8 |
Quality of studies 2 | |
Mean (range: 15–38) | 27.6 (SD: 5.9) |
1 Categories are not mutually exclusive. 2 Quality scores range from 0–42.
3.2. Results by Type of Tobacco Product
Of 20 studies on flavored tobacco products included in our qualitative systematic review, 10 examined hookah, six examined e-cigarettes, two examined little cigars and cigarillos (LCCs), and three examined other tobacco products, including cigarettes. Results, organized by type of tobacco product, can be seen in Table 2.
Table 2.
Study ID | Product | Study Setting & Population | Sample Size | Quality Score | Main Findings and Illustrative Quotes |
---|---|---|---|---|---|
Afifi, 2013 [18] | Hookah |
|
81 focus group discussion (8–10 people per group), 38 one-on-one interviews | 38 |
|
Griffiths 2011 [19] | Hookah |
|
20 one-on-one interviews | 23 |
|
Hammal, 2016 [20] | Hookah |
|
16 focus groups (75 participants) | 24 |
|
Hammal, 2016 [21] | Hookah |
|
27 one-on-one interviews | 15 |
|
Kotecha, 2016 * [22] | Hookah |
|
16 one-on-one interviews | 33 |
|
Jawad, 2013 [23] | Hookah |
|
7 focus groups (32 participants) | 24 |
|
Nakkash, 2011 [24] | Hookah |
|
25 focus groups (8–10 people per group) and 9 one-on-one interviews | 31 |
|
Roskin, 2009 [25] | Hookah |
|
12 one-on-one interviews | 27 |
|
Sharma, 2014 [26] | Hookah |
|
49 one-on-one interviews | 33 |
|
Yen, 2012 [27] | Hookah |
|
5 one-on-one interviews | 16 |
|
Cheney, 2016 [28] | E-cigarette |
|
30 one-on-one interviews | 34 |
|
Cooper, 2016 [29] | E-cigarette |
|
50 one-on-one interviews | 26 |
|
Kong, 2015 [30] | E-cigarette |
|
18 focus groups (127 total participants) | 33 |
|
Kotecha, 2016 * [22] | E-cigarette |
|
16 one-on-one interviews | 33 |
|
Wagoner, 2016 [31] | E-cigarette |
|
10 focus groups (77 total participants) | 25 |
|
De Andrade, 2016 [32] | E-cigarette |
|
182 one-on-one interviews | 24 |
|
Sterling, 2015 [33] | LCC |
|
12 focus groups (90 total participants) | 32 |
|
Sterling, 2015 [34] | LCC |
|
12 focus groups (90 total participants) | 32 |
|
| |||||
Moodie, 2015 [35] | Cigarettes |
|
12 focus groups (75 total participants) | 22 |
|
Choi, 2012 [36] | Various |
|
11 focus groups (68 total participants) | 32 |
|
Wray, 2012 [37] | Various |
|
8 focus groups (67 total participants) | 27 |
|
* study appears twice.
3.2.1. Hookah
Ten studies examined flavors in waterpipe or hookah (hereafter referred to as hookah), most of which were studies from Western countries (Scotland, Canada, UK, U.S.) (see Table 2) [18,19,20,21,22,23,24,25,26,27]. In all ten studies, participants spoke about flavors as appealing and/or tasty; in five of the studies, participants also spoke positively about the widespread availability of different flavors and the ability to mix flavors [18,22,24,26,27].
In four studies from Canada, the UK, and the U.S., young adults reported that they used hookah specifically because of the flavors and noted that they would not use other tobacco products, such as cigarettes or piped tobacco [19,22,25,26]. As one young adult user said, “Lots of people I know smoke shisha and don’t smoke cigarettes because they don’t like the taste of it, whereas shisha tastes really nice” [22]. In part, these participants noted the appealing taste of flavors; they also reported believing that flavored hookah was less harmful than cigarettes, as reported in three studies from Canada, the U.S., and the UK [19,20,25]. As one young adult user said, “Fruit flavor makes it less harmful. I don’t believe it’s as harmful as cigarettes. Everyone seems to believe this, that it’s less toxic. I know students who smoke shisha but wouldn’t smoke cigarettes. If offered a cigarette, they’d turn it down” [25].
In two studies from Canada and Lebanon, adult users and non-users of hookah said that flavors were a reason why younger people used hookah [21,24], and in one study among young adults in Canada, flavors were mentioned as the reason for initiating use of hookah: “I think it had to do with the flavor that got me to smoke it. It has a lot of variety” [20]. In one study among young adults in the UK, users described being addicted to hookah, in part because of flavors [22]. Lastly, in a study with 27 adults in Canada, most participants felt that there should be additional restrictions on flavored hookah [21].
3.2.2. E-Cigarettes
Six studies examined flavors in e-cigarettes, e-hookahs, e-shisha, and vape pens (hereafter referred to as e-cigarettes) [22,28,29,30,31,32]. All studies discussed how flavors contributed to the appeal of e-cigarettes. Two studies from the U.S. also mentioned how flavors allowed e-cigarette users to be more social, for instance, by serving as a conversation starter or by allowing people to share flavors in social settings [28,31].
In three studies with young adults and adolescents from the U.S. and Scotland, participants mentioned how flavors contributed to their initiation, experimentation, and/or continued use of e-cigarettes or other tobacco products [28,30,32]. Young adult users of hookah in the UK described the belief that use of e-cigarettes (especially tobacco flavored) could lead to use of other tobacco products, stating, “Non-smokers could then be encouraged to smoke and try tobacco, like actual cigarettes and tobacco flavored shisha” [22]. Additionally, in a study in Scotland, some adolescents felt that e-cigarettes should be regulated because these devices could lead younger generations to start smoking [32]. Conversely, in one U.S. study, two e-cigarette users (out of 50 total participants) noted that they felt that flavors played an instrumental (positive) role in cigarette smoking cessation, stating “If I don’t like the flavor, I’m going to smoke a cigarette in a weird way, because it's not satisfying. It’s like I'm a slave to nicotine, but if you find a flavor that you like, you're more inclined to be like, “This is sufficient. I don’t want (a cigarette)” [29].
3.2.3. Little Cigars and Cigarillos (LCCs)
Two studies examined flavors in LCCs among U.S. young adult users of cigarettes and/or LCCs [33,34]. In one study, participants perceived flavored LCCs as less harmful than regular cigarettes due to the packaging, colors, and taste of the flavors [33]. For example, one participant said, “Also the flavors they put the fruits there...people might assume that it’s okay it’s got fruits on it, cause this one’s even got a picture of a fruit all cut up and it looks good. So, they’re associating it with the natural” [33]. In another study, participants noted the appeal of flavored LCCs and described how flavors and their variety led to experimentation and initiation of LCCs [34]. For example, one participant said, “And I was like it (LCC) smells good, so it made me want to hit it. But I’m like I don’t like the taste of this. So, then I started of course experimenting with different ones” [34]. In this same study, participants also noted that flavored LCCs affected smoking cessation. Specifically, one participant discussed a friend who thought he could quit smoking cigarettes by using flavored LCCs since they take longer to burn. However, at the end of the day, the friend ended up smoking more flavored LCCs than originally intended and not being able to quit cigarettes. Thus, in this case, use of flavored LCCs actually perpetuated tobacco use [34].
3.2.4. Other Tobacco Products
Three studies examined flavors in other tobacco products, which included dissolvables, snus, cigarettes, and other unspecified products [35,36,37]. In these studies, young adults in the U.S. described the appeal of dissolvable tobacco products [36] and the belief that flavored tobacco products made people think these products were safer than cigarettes given their more tolerable odor [37]. Additionally, in one cigarette study where adolescents and young adults in Scotland were shown different colored cigarettes (standard, pink, brown), participants perceived the pink cigarette as more appealing and less harmful because it looked more like “candy sticks” and its color indicated a nicer taste, regardless of the actual flavor of the product [35].
4. Discussion
This is the first systematic review examining qualitative studies in the U.S. and internationally of non-menthol flavored tobacco products. Our review extends research by Feirman et al. [14], by including international studies, incorporating more studies on non-cigarette products, such as hookah, examining harm perceptions in addition to appeal, and reviewing recent literature published in the last three years.
Supporting previous quantitative research on the appeal of flavored tobacco products [1,2,3], we found that nearly all 20 studies included in our review reported positive perceptions of flavored tobacco products. Regardless of product type, common reasons for the appeal of flavored tobacco products included the availability and novelty of flavors; the attractiveness of product packaging and marketing of flavors; the associations between certain flavors and relaxation; the tastiness of flavors; the ability to mix flavors (especially for e-cigarettes); and the social aspect of sharing flavors. Moreover, all but four of these studies focused on adolescents and young adults, and all but one study focused on non-cigarette flavored tobacco products, such as hookah and e-cigarettes, suggesting that flavored tobacco products (other than cigarettes) are widely appealing to adolescents and young adults.
Given the favorability of flavored non-menthol tobacco products, the reasons why individuals use these products, and the appeal of these products to youth and young adults, our findings extend support for banning non-menthol flavors in tobacco products. A growing number of studies have established the harmfulness of non-cigarette tobacco products, including hookah [38], cigars [39] and e-cigarettes [40,41,42,43], particularly for adolescents. These products contain nicotine, which has been shown to be harmful for developing brains of adolescents [44], and early exposure to nicotine may lead to future tobacco product use. For instance, longitudinal research has shown that e-cigarette use in adolescence is associated with future tobacco product use, including cigarettes [45,46,47,48]. Thus, our findings point to regulation of all flavored tobacco products, including e-cigarettes, since they are heavily marketed to youth and may be detrimental to brain development and for future tobacco product use. Furthermore, in two studies included in our review (one involving adults’ opinions of hookah; one involving adolescents’ opinions of e-cigarettes), individuals reported favorable attitudes toward regulation of flavored hookah and e-cigarettes as a way to deter youth initiation of tobacco [21,32]. These findings may be useful to tobacco regulatory agencies as further evidence regarding the importance of regulation of flavored non-menthol tobacco products, as well as the acceptability of potential regulation.
Most concerning in our review was the fact that in six studies that assessed harm perceptions (examining hookah, LCCs, and other flavored tobacco products), participants mentioned flavors as a reason why they perceive certain tobacco products as less harmful than cigarettes [19,20,25,33,35,37]. Prior systematic reviews from Huang et al. [15] and Feirman et al. [14] identified several quantitative studies illustrating associations between flavor descriptors and reduced harm perceptions. Our study extends these findings by highlighting potential pathways though which these associations occur. For example, product packaging including colors and flavor descriptors (e.g., fruit flavors and naturalness), and the sweet fruity smells of flavored tobacco products appear to act as implicit modified risk claims that lead users to perceive flavored products as less harmful than cigarettes. Future research should investigate ways in which flavors alter risk perception of tobacco use. Public health interventions and education campaigns could target beliefs associated with flavors to increase risk perceptions of flavored tobacco products and decrease initiation and/or consumption of such products. Moreover, given these patterns across different flavored tobacco products, regulation of all types of flavored tobacco products (rather than some specific types) may be important.
Participants across studies mentioned how flavors led to their experimentation and/or initiation of flavored tobacco products, consistent with previous quantitative research describing the role of flavors in smoking initiation [1,2,3]. For instance, in a large nationally representative survey in the U.S., researchers found that the majority of youth ever-tobacco users (81%) reported that the first product they used was flavored [3]. The relationship between flavored tobacco product use and cigarette smoking cessation is less consistent. In our review, two studies (one on e-cigarettes and one on LCCs) provided participants’ perspectives on how flavors may affect cigarette use. Specifically, participants mentioned that e-cigarette flavors could aid smoking cessation (if a participant liked a flavored e-cigarette, they would not feel the need to smoke cigarettes) [29] and that flavored LCCs may deter cigarette smoking cessation (by perpetuating tobacco use) [34].
Flavors are often viewed as a major reason for young people starting out using tobacco products (often with lower nicotine) and moving up to stronger products (with higher nicotine content) over time [1]. Interestingly we found that in four hookah studies, participants noted that they would use flavored hookah, but not other tobacco products, such as cigarettes [19,22,25,26]. On the other hand, in two e-cigarette studies, participants noted that use of flavored e-cigarettes could lead to use of other tobacco products, such as hookah or cigarettes [22,32]. These findings suggest that flavored hookah or e-cigarettes may appeal to different segments of the population than cigarettes. Given associations between initiation of flavored tobacco products in youth or young adulthood and established tobacco use later in life [1], our results suggest the potential of flavors to introduce youth to other tobacco products, but that these patterns may differ by type of product first used. Future longitudinal research could examine whether the type of flavored tobacco products plays a differential role in tobacco use patterns throughout the life course.
Limitations
Our study had several limitations. First, our review is limited to studies published in peer-reviewed journals; other relevant information may have been reported in reports, dissertations, or the grey literature, which would not be captured in this review. Second, no published articles examined the role of flavors in attitudes, perceptions, or experiences with smokeless tobacco products. Third, while we reported quotes from participants and described the context of the quotes, we were not able to assess the extent to which beliefs were held or stated by participants in the studies. In other words, we were unable to assess the prevalence of specific beliefs. Fourth, many studies did not state qualities of participants giving quotes (e.g., age, smoking status, etc.), which limits our ability to differentiate themes or results by types of participants. Fifth, most of the studies did not include enough primary data (e.g., participant quotes) to use a theoretical framework to extract themes form the body of research we reviewed. As a result, we were unable to employ a theoretically grounded approach to evaluate these studies. Sixth, while we assessed the quality of studies included in this review using a validated tool, there are no published thresholds for what constitutes low, medium, or high quality. As a result, we did not use criteria to rank or exclude studies. Instead, since 95% of the studies included in our review met at least 50% of the recommended criteria in our quality assessment tool (i.e., the highest score of 42), we retained all eligible studies and did not exclude articles based on quality information. Last, our review focused on perceptions and experiences with non-menthol flavored tobacco products. While previous reviews have examined the public health impact of menthol [8,9,10,11,12,13], future research could explore the role of menthol in attitudinal and behavioral outcomes among diverse populations and various tobacco products.
5. Conclusions
Our review extends findings from quantitative studies on flavored tobacco products and provide insights into perceptions of and experiences with flavored tobacco products. More specifically, we found that in nearly all 20 studies included in our review, participants reported positive perceptions of flavored tobacco products and mentioned how flavors led to their experimentation and/or initiation of flavored tobacco products. Moreover, all but four of these studies focused on adolescents and young adults, and all but one study focused on non-cigarette flavored tobacco products, such as hookah and e-cigarettes, suggesting that flavored tobacco products (other than cigarettes) are widely appealing to this population. Our findings provide additional support to ban non-menthol flavors in tobacco products in the US and internationally, especially to curb tobacco use among youth.
Acknowledgments
Research reported in this publication was supported by grant number P50 CA180907 from the National Cancer Institute and the FDA Center for Tobacco Products (CTP). The content is solely the responsibility of the authors and does not necessarily represent the official views of the NIH or the Food and Drug Administration.
Author Contributions
Adam O. Goldstein and Li-Ling Huang designed the idea for the review; Clare Meernik, Hannah M. Baker, and Li-Ling Huang performed the searches, reviewed articles, and extracted the data from included articles; Sarah D. Kowitt and Amira Osman drafted the outline for the manuscript and determined how to frame study findings; Sarah D. Kowitt analyzed the data; Clare Meernik, Hannah M. Baker, Li-Ling Huang, Amira Osman, and Adam O. Goldstein contributed ideas to analyze and interpret the data; Sarah D. Kowitt wrote the first draft of the paper, which was revised by all authors. All authors read and approved the final manuscript.
Conflicts of Interest
The authors declare no conflict of interest. The founding sponsors had no role in the design of the study; in the collection, analyses, or interpretation of data; in the writing of the manuscript, and in the decision to publish the results.
References
- 1.Villanti A.C., Richardson A., Vallone D.M., Rath J.M. Flavored tobacco product use among U.S. young adults. Am. J. Prev. Med. 2013;44:388–391. doi: 10.1016/j.amepre.2012.11.031. [DOI] [PubMed] [Google Scholar]
- 2.Corey C.G., Ambrose B.K., Apelberg B.J., King B.A. Flavored tobacco product use among middle and high school students—United States, 2014. Morb. Mortal. Wkly. Rep. 2015;64:1066–1070. doi: 10.15585/mmwr.mm6438a2. [DOI] [PubMed] [Google Scholar]
- 3.Ambrose B.K., Day H.R., Rostron B., Conway K.P., Borek N., Hyland A., Villanti A.C. Flavored tobacco product use among U.S. youth aged 12–17 years, 2013–2014. JAMA. 2015;314:1871–1873. doi: 10.1001/jama.2015.13802. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 4.Public Law 111-31 H.R. 1256. Family Smoking Prevention and Tobacco Control Act. [(accessed on 25 August 2016)]; Available online: http://www.gpo.gov/fdsys/pkg/PLAW-111publ31/pdf/PLAW-111publ31.pdf.
- 5.Food and Drug Administration Deeming tobacco products to be subject to the federal food, drug, and cosmetic act, as amended by the family smoking prevention and tobacco control act; regulations on the sale and distribution of tobacco products and required warning statements for tobacco products. Fed. Regist. 2016;79:1–499. [PubMed] [Google Scholar]
- 6.European Commission 10 Key Changes for Tobacco Products Sold in the EU. [(acessed on 22 September 2016)]; Available online: http://europa.eu/rapid/press-release_IP-16–1762_en.htm.
- 7.Tobacco Control Legal Consortium How Other Countries Regulate Flavored Tobacco Products. [(acessed on 27 September 2016)]; Available online: http://publichealthlawcenter.org/sites/default/files/resources/tclc-fs-global-flavored-regs-2015.pdf.
- 8.Anderson S.J. Menthol cigarettes and smoking cessation behaviour: A review of tobacco industry documents. Tob. Control. 2011;20:ii49–ii56. doi: 10.1136/tc.2010.041947. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 9.Lee Y.O., Glantz S.A. Menthol: Putting the pieces together. Tob. Control. 2011;20:ii1–ii7. doi: 10.1136/tc.2011.043604. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 10.Kreslake J.M., Wayne G.F., Connolly G.N. The menthol smoker: Tobacco industry research on consumer sensory perception of menthol cigarettes and its role in smoking behavior. Nicotine Tob. Res. 2008;10:705–715. doi: 10.1080/14622200801979134. [DOI] [PubMed] [Google Scholar]
- 11.Yerger V.B., McCandless P.M. Menthol sensory qualities and smoking topography: A review of tobacco industry documents. Tob. Control. 2011;20:ii37–ii43. doi: 10.1136/tc.2010.041988. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 12.Food and Drug Administration Preliminary Scientific Evaluation of the Possible Public Health Effects of Menthol Versus Nonmenthol Cigarettes. [(acessed on 15 March 2017)]; Available online: https://www.fda.gov/downloads/ScienceResearch/SpecialTopics/PeerReviewofScientificInformationandAssessments/UCM361598.pdf.
- 13.Tobacco Products Scientific Advisory Committee Menthol Cigarettes and Public Health: Review of the Scientific Evidence and Recommendations. [(acessed on 15 March 2017)]; Available online: https://www.fda.gov/downloads/AdvisoryCommittees/CommitteesMeetingMaterials/TobaccoProductsScientificAdvisoryCommittee/UCM269697.pdf.
- 14.Feirman S.P., Lock D., Cohen J.E., Holtgrave D.R., Li T. Flavored tobacco products in the United States: A systematic review assessing use and attitudes. Nicotine Tob. Res. 2016;18:739–749. doi: 10.1093/ntr/ntv176. [DOI] [PubMed] [Google Scholar]
- 15.Huang L.L., Baker H.M., Meernik C., Ranney L.M., Richardson A., Goldstein A.O. Impact of non-menthol flavours in tobacco products on perceptions and use among youth, young adults and adults: A systematic review. Tob. Control. 2016 doi: 10.1136/tobaccocontrol-2016-053196. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 16.Creswell J.W. Qualitative inquiry and Research Design: Choosing among Five Approaches. SAGE; Thousand Oaks, CA, USA: 2013. [Google Scholar]
- 17.Sirriyeh R., Lawton R., Gardner P., Armitage G. Reviewing studies with diverse designs: The development and evaluation of a new tool. J. Eval. Clin. Pract. 2012;18:746–752. doi: 10.1111/j.1365-2753.2011.01662.x. [DOI] [PubMed] [Google Scholar]
- 18.Afifi R., Khalil J., Fouad F., Hammal F., Jarallah Y., Abu Farhat H., Ayad M., Nakkash R. Social norms and attitudes linked to waterpipe use in the eastern Mediterranean region. Soc. Sci. Med. 2013;98:125–134. doi: 10.1016/j.socscimed.2013.09.007. [DOI] [PubMed] [Google Scholar]
- 19.Griffiths M.A., Harmon T.R., Gilly M.C. Hubble bubble trouble: The need for education about and regulation of hookah smoking. J. Public Policy Mark. 2011;30:119–132. doi: 10.1509/jppm.30.1.119. [DOI] [Google Scholar]
- 20.Hammal F., Wild T.C., Nykiforuk C., Abdullahi K., Mussie D., Finegan B.A. Waterpipe (hookah) smoking among youth and women in Canada is new, not traditional. Nicotine Tob. Res. 2016;18:757–762. doi: 10.1093/ntr/ntv152. [DOI] [PubMed] [Google Scholar]
- 21.Hammal F., Wild T.C., Finegan B.A. Knowledge about the waterpipe (hookah), a qualitative assessment among community workers in a major urban center in Canada. J. Community Health. 2016;41:689–696. doi: 10.1007/s10900-015-0143-9. [DOI] [PubMed] [Google Scholar]
- 22.Kotecha S., Jawad M., Iliffe S. Knowledge, attitudes and beliefs towards waterpipe tobacco smoking and electronic shisha (e-shisha) among young adults in London: A qualitative analysis. Prim. Health Care Res. Dev. 2016;17:166–174. doi: 10.1017/S1463423615000237. [DOI] [PubMed] [Google Scholar]
- 23.Jawad M., Jawad S., Mehdi A., Sardar A., Jawad A.M., Hamilton F.L. A qualitative analysis among regular waterpipe tobacco smokers in London universities. Int. J. Tuberc. Lung Dis. 2013;17:1364–1369. doi: 10.5588/ijtld.12.0923. [DOI] [PubMed] [Google Scholar]
- 24.Nakkash R.T., Khalil J., Afifi R.A. The rise in narghile (shisha, hookah) waterpipe tobacco smoking: A qualitative study of perceptions of smokers and non smokers. BMC Public Health. 2011;11:315. doi: 10.1186/1471-2458-11-315. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 25.Roskin J., Aveyard P. Canadian and english students’ beliefs about waterpipe smoking: A qualitative study. BMC Public Health. 2009;9:10. doi: 10.1186/1471-2458-9-10. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 26.Sharma E., Clark P.I., Sharp K.E. Understanding psychosocial aspects of waterpipe smoking among college students. Am. J. Health Behav. 2014;38:440–447. doi: 10.5993/AJHB.38.3.13. [DOI] [PubMed] [Google Scholar]
- 27.Yen K.P., Harun N., Ishak F., Anuar N.A.I.M., Karim N.A., Azman A., Mahmood T.S.T. Contributory factors to the smoking of shisha among teenagers in the perak city of Ipoh: A preliminary qualitative survey. Int. J. Public Health Res. 2012;2:80–84. [Google Scholar]
- 28.Cheney M.K., Gowin M., Wann T.F. Electronic cigarette use in straight-to-work young adults. Am. J. Health Behav. 2016;40:268–279. doi: 10.5993/AJHB.40.2.12. [DOI] [PubMed] [Google Scholar]
- 29.Cooper M., Harrell M.B., Perry C.L. A qualitative approach to understanding real-world electronic cigarette use: Implications for measurement and regulation. Prev. Chronic Dis. 2016;13:E07. doi: 10.5888/pcd13.150502. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 30.Kong G., Morean M.E., Cavallo D.A., Camenga D.R., Krishnan-Sarin S. Reasons for electronic cigarette experimentation and discontinuation among adolescents and young adults. Nicotine Tob. Res. 2015;17:847–854. doi: 10.1093/ntr/ntu257. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 31.Wagoner K.G., Cornacchione J., Wiseman K.D., Teal R., Moracco K.E., Sutfin E.L. E-cigarettes, hookah pens and vapes: Adolescent and young adult perceptions of electronic nicotine delivery systems. Nicotine Tob. Res. 2016;18:2006–2012. doi: 10.1093/ntr/ntw095. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 32.De Andrade M., Angus K., Hastings G. Teenage perceptions of electronic cigarettes in Scottish tobacco-education school interventions: Co-production and innovative engagement through a pop-up radio project. Perspect. Public Health. 2016;136:288–293. doi: 10.1177/1757913915612109. [DOI] [PubMed] [Google Scholar]
- 33.Sterling K.L., Fryer C.S., Fagan P. The most natural tobacco used: A qualitative investigation of young adult smokers’ risk perceptions of flavored little cigars and cigarillos. Nicotine Tob. Res. 2016;18:827–833. doi: 10.1093/ntr/ntv151. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 34.Sterling K.L., Fryer C.S., Nix M., Fagan P. Appeal and impact of characterizing flavors on young adult small cigar use. Tob. Regul. Sci. 2015;1:42–53. doi: 10.18001/TRS.1.1.5. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 35.Moodie C., Ford A., Mackintosh A., Purves R. Are all cigarettes just the same? Female’s perceptions of slim, coloured, aromatized and capsule cigarettes. Health Educ. Res. 2015;30:1–12. doi: 10.1093/her/cyu063. [DOI] [PubMed] [Google Scholar]
- 36.Choi K., Fabian L., Mottey N., Corbett A., Forster J. Young adults’ favorable perceptions of snus, dissolvable tobacco products, and electronic cigarettes: Findings from a focus group study. Am. J. Public Health. 2012;102:2088–2093. doi: 10.2105/AJPH.2011.300525. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 37.Wray R.J., Jupka K., Berman S., Zellin S., Vijaykumar S. Young adults’ perceptions about established and emerging tobacco products: Results from eight focus groups. Nicotine Tob. Res. 2012;14:184–190. doi: 10.1093/ntr/ntr168. [DOI] [PubMed] [Google Scholar]
- 38.World Health Organization Waterpipe Tobacco Smoking: Health Effects, Research Needs and Recommended Actions by Regulators. [(accessed on 7 March 2017)]; Available online: http://www.who.int/tobacco/global_interaction/tobreg/Waterpiperecommendation_Final.pdf.
- 39.Centers for Disease Control and Prevention Cigars. Smoking & Tobacco Use. [(accessed on 7 March 2017)]; Available online: https://www.cdc.gov/tobacco/data_statistics/fact_sheets/tobacco_industry/cigars/
- 40.Slotkin T.A. Cholinergic systems in brain development and disruption by neurotoxicants: Nicotine, environmental tobacco smoke, organophosphates. Toxicol. Appl. Pharmacol. 2004;198:132–151. doi: 10.1016/j.taap.2003.06.001. [DOI] [PubMed] [Google Scholar]
- 41.Grana R.A. Electronic cigarettes: A new nicotine gateway? J. Adolesc. Health. 2013;52:135–136. doi: 10.1016/j.jadohealth.2012.11.007. [DOI] [PubMed] [Google Scholar]
- 42.Pediatrics A.A.O. Electronic nicotine delivery systems. Pediatrics. 2015;136:9. doi: 10.1542/peds.2015-3222. [DOI] [PubMed] [Google Scholar]
- 43.McRobbie H., Bullen C., Hartmann-Boyce J., Hajek P. Electronic cigarettes for smoking cessation and reduction. Cochrane Database Syst. Rev. 2014;12:CD010216. doi: 10.1002/14651858.CD010216.pub2. [DOI] [PubMed] [Google Scholar]
- 44.Dwyer J.B., McQuown S.C., Leslie F.M. The dynamic effects of nicotine on the developing brain. Pharmacol. Ther. 2009;122:125–139. doi: 10.1016/j.pharmthera.2009.02.003. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 45.Leventhal A.M., Strong D.R., Kirkpatrick M.G., Unger J.B., Sussman S., Riggs N.R., Stone M.D., Khoddam R., Samet J.M., Audrain-McGovern J. Association of electronic cigarette use with initiation of combustible tobacco product smoking in early adolescence. JAMA. 2015;314:700–707. doi: 10.1001/jama.2015.8950. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 46.Wills T.A., Knight R., Sargent J.D., Gibbons F.X., Pagano I., Williams R.J. Longitudinal study of e-cigarette use and onset of cigarette smoking among high school students in Hawaii. Tob. Control. 2016;26:34–39. doi: 10.1136/tobaccocontrol-2015-052705. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 47.Barrington-Trimis J.L., Urman R., Berhane K., Unger J.B., Cruz T.B., Pentz M.A., Samet J.M., Leventhal A.M., McConnell R. E-cigarettes and future cigarette use. Pediatrics. 2016;138:e20160379. doi: 10.1542/peds.2016-0379. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 48.Bunnell R.E., Agaku I.T., Arrazola R.A., Apelberg B.J., Caraballo R.S., Corey C.G., Coleman B.N., Dube S.R., King B.A. Intentions to smoke cigarettes among never-smoking us middle and high school electronic cigarette users: National youth tobacco survey, 2011–2013. Nicotine Tob. Res. 2015;17:228–235. doi: 10.1093/ntr/ntu166. [DOI] [PMC free article] [PubMed] [Google Scholar]