Under the shadow of the tobacco epidemic, the sale and use of e-cigarettes and other vapour devices is increasing dramatically.
A contentious debate has risen within public health over the harms and benefits of these devices.
Clearing the Air seeks to clarify the issues with a systematic review that informs the pressing regulatory and public health decisions to be made regarding these new products.
Methods/design
Using an integrated knowledge translation approach, public health researchers and knowledge users will work collaboratively throughout the project. Our research questions are the following: (1) What are the health risks and benefits of vapour devices, and how do these compare to cigarettes? (2) What is the harm reduction potential of vapour devices for individuals, the environment, and society? (3) Does youth vapour device experimentation lead to cigarette use? (4) Can vapour devices be effective aids for tobacco cessation? and (5) What is the potential toxicity of second-hand vapour?
We are using meta-narrative review to synthesize studies from diverse research traditions because of its capacity to address contestations around a topic. The project has six phases. In the planning phase, we finalized the research questions. In the search phase, we are locating academic publications and grey literature aided by a research librarian. The mapping phase involves categorizing these papers into research traditions to understand different perspectives on the evidence for each research question. In the appraisal phase, we will select and evaluate the relevant papers. Finally, in the synthesis phase, using analytic techniques unique to meta-narrative methodology, we will compare and contrast the evidence from different research traditions to answer our research questions, identifying overarching meta-narratives. In the final stage, the full team will draft recommendations to be disseminated through a variety of knowledge translation strategies.
Discussion
Meta-narrative synthesis has the unique capacity to expose the debates that are influencing the interpretation of empirical studies on vapour devices. We seek to “clear the air” with an even-handed review of the evidence and an understanding of the tensions within public health so that we can offer clear-headed recommendations for policy, regulation, and future research.
Background
The tobacco epidemic causes almost 6 million deaths worldwide every year and, if current trends are unchecked, the rate will rise to 8 million by 2030 [1]. At the same time, the sale and use of electronic cigarettes and vapour devices is increasing dramatically, from US $573 million in 2009 to US $6.48 billion in 2014 [2]. The public health community is divided, even polarized, over how the use of these devices will impact the tobacco epidemic [3]. Some tobacco control advocates predict that e-cigarettes will increase rates of cigarette uptake [4, 5], especially among youth [6, 7]. Others envision that these devices have potential for aiding cessation efforts, or reducing harm among people who continue to smoke [8–11].
In Canada, in 2013, a group of 90 public health and addiction specialists participated in a forum on the potential responses to the growing use of vapour devices [12]. Although consensus was achieved on the need for product control and regulating sales to minors, dissent remained on all other issues. The debate in the public health community is fueled by the lack of a comprehensive review of the research on the range of health and social impacts of these devices. At present, some research suggests benefits for the use of vapour devices [13–15], while other evidence identifies harms [16–19]. Even the conclusions of systematic reviews are contradictory, with some claiming minimal harm and with others not recommending their use [9, 20–26]. Resolving these contradictions is essential to move forward on policy and regulation.
In this paper, we use the term vapour devices to include the wide range of consumer products that heat nicotine and non-nicotine liquids to produce vapour that is inhaled by the user. The various product designs and terms include electronic or e-cigarette, electronic nicotine delivery system (ENDS), cig-a-like, mod, e-hookah, vape pen, tank system, vaping device, e-cigar, and third generation devices.
Both the public and the public health community have an interest in the potential health consequences from vapour device use. Individuals are worried about possible harm to themselves from their exposure to vapour. For example, the absence of regulation on legal non-nicotine devices in Canada has lead to vapour devices being used where cigarette use is prohibited. As a consequence, people in schools, workplaces, and public venues are concerned about the potential harms to bystanders exposed to possible aerosol contaminants (i.e. second-hand vapour). From a public health perspective, in addition to questions about potential health risks, these devices raise issues about their potential contribution to health inequities. Even though smoking is declining in the overall population, sexual minorities, street-involved people, persons with mental illness, and indigenous populations all have much higher rates of smoking [27–29]. If vapour device use results in additional harms, it may disproportionately affect these populations. Conversely, if these devices have harm reduction potential or aid in cessation, they may substantially benefit health among these groups.
Purpose and research questions
The purpose of this meta-narrative review is to synthesize the available evidence on vapour devices with respect to health and social impacts and their harm reduction potential. We are funded by the Canadian Institutes of Health Research through a peer-reviewed Knowledge Synthesis grant. Because we use only secondary data in the form of published materials and articles from the grey literature, no human subject ethical approval is necessary. Our approach uses an integrated knowledge translation model [30] in which public health researchers and knowledge users (e.g. policy and decision makers) work collaboratively to identify the research questions, interpret the results, make recommendations, and engage in knowledge translation.
In our initial scoping of the literature in April 2014, we located 101 primary research studies exploring a range of topics related to these devices including use patterns (26), health impacts on users and by-standers (24), prevalence (15), use in tobacco cessation (13), product toxicology (10), youth uptake (9), and consumer marketing (4). We noted a steadily increasing number of studies on vapour devices every year since 2009, as has been reported in a bibliometric analysis conducted in June, 2014 [31]. This sets the stage for a broad-based systematic review.
The research questions, developed in consultation with our knowledge user partners, are:
- What are the health risks and benefits of vapour devices, and how do these compare to cigarettes?
- What is the harm reduction potential of vapour devices for individuals, the environment, and society?
- Does youth vapour device experimentation lead to cigarette use?
- Can vapour devices be effective tools for tobacco cessation?
- What is the potential toxicity of second-hand vapour?
The goal of Clearing the Air: A Systematic Meta-Narrative Review on the Harms and Benefits of E-Cigarettes and Vapour Devices is to generate a research synthesis that can inform the pressing regulatory and public health decisions to be made, specifically in British Columbia and Canada but also internationally. We seek to “clear the air” in this contentious public health debate with an appeal to the available evidence. This protocol paper describes how the research will be conducted.
Methods/design
We selected meta-narrative synthesis (or review), as the most appropriate approach for the study. As noted above, studies on vapour devices have been conducted in diverse research traditions, with widely different methodologies, and often different, although related, research questions. This heterogeneity makes it difficult to apply a more traditional systematic review approach because each of the different research traditions may only address one or perhaps two of our research questions. In addition, our preliminary review revealed that the same evidence was often used in support of completely contradictory conclusions.
A meta-narrative review is a relatively recent constructivist synthesis methodology developed to summarize, synthesize, and interpret a diverse body of literature from multiple traditions that use different methods, theoretical perspectives, and data types [32–34]. It is systematic in that it is conducted “according to an explicit, rigorous and transparent method” ([33], p. 418). This methodology involves the judicious combination of qualitative and quantitative research evidence, the theoretical literature, and other relevant sources of data (e.g. editorials, and news items in academic journals). Meta-narrative reviewers attempt to make sense of the complex and often contested literature in a topic area. Thus, the contentious debate around vapour devices makes meta-narrative synthesis a good fit for this study because the methodology is “particularly suited to topics where there is dissent about the nature of what is being studied, and what is the best empirical approach to studying it. . . [ It can] help build common ground between social researchers and policy teams” ([35], p. 2).
The protocol described in this paper has been registered with PROSPERO [CRD42015025267]. We have included a populated PRISMA-P checklist describing our adherence to these guidelines (see Additional file 1). Because meta-narrative review is a relatively new synthesis methodology that differs in some ways from a more traditional systematic review, our protocol does not comply fully with the PRISMA-P checklist. Nonetheless, it is substantially compliant.
A defining feature of meta-narrative synthesis is its six guiding principles, which are integrated into each step of the review process. In Table 1, we identify the six principles, define them, and provide an example of how we are applying each principle in our review.
The meta-narrative review quality standards [36] and training materials [37] guided the development of the research design. This project is segmented into six stages, each one incorporating a knowledge translation component. Meta-narrative synthesis methodology is not linear, and different processes may happen during one step, or may be repeated later in the review [36].
Marjorie MacDonald et al. – Systematic Reviews – 2016-05-21.
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