Factors in multiple behaviour change interventions affecting smoking cessation success: a rapid realist review.


 Background Smoking continues to be a leading cause of preventable chronic disease-related morbidity and mortality, excess healthcare expenditure, and lost work productivity. Tobacco users are disproportionately more likely to be engaging in other modifiable risk behaviours such as excess alcohol consumption, physical inactivity, and poor diet. While hundreds of interventions addressing the clustering of smoking and other modifiable risk behaviours have been conducted worldwide, there is insufficient information available about what components of these interventions help to promote successful smoking cessation . The aim of this rapid realist review was to identify possible mechanisms used in multiple health behaviour change interventions (targeting tobacco and two or more additional risk behaviours) that are associated with effectively changing tobacco use. Methods This realist review method incorporated the following steps: (1) clarifying the scope, (2) searching for relevant evidence, (3) relevance confirmation, data extraction, and quality assessment, (4) data analysis and synthesis. Results Of the 20,423 articles screened, 138 articles were included in this realist review. Following Michie et al.’s behavior change model (the COM-B model), capability, opportunity, and motivation were used to identify the mechanisms of behaviour change. Universally, increasing opportunities (i.e. factors that lie outside the individual that prompt the behaviour or make it possible) for participants to engage in healthy behaviours was associated with smoking cessation success. However, increasing participant’s capability or motivation to make a behaviour change was only successful within certain contexts. Conclusion In order to address multiple health behaviours and assist individuals in quitting smoking, public health promotion interventions need to shift away from ‘individualistic epidemiology’ and invest resources into modifying factors that exist outside of the individual (i.e. creating a supportive environment). Study registration PROSPERO registration number: CRD42017064430

were used to identify the mechanisms of behaviour change. Universally, increasing opportunities (i.e. factors that lie outside the individual that prompt the behaviour or make it possible) for participants to engage in healthy behaviours was associated with smoking cessation success. However, increasing participant's capability or motivation to make a behaviour change was only successful within certain contexts.
Conclusion In order to address multiple health behaviours and assist individuals in quitting smoking, public health promotion interventions need to shift away from 'individualistic epidemiology' and invest resources into modifying factors that exist outside of the individual (i.e. creating a supportive environment). Study registration PROSPERO registration number: CRD42017064430

Background
Smoking continues to be a leading cause of preventable chronic disease-related morbidity and mortality, excess healthcare expenditure, and lost work productivity [1][2][3][4][5]. While tobacco control efforts have made significant strides in reducing the overall prevalence of smoking in North America, millions of individuals report smoking in 2018 [6][7][8]. Furthermore, disparities in smoking remain prevalent across population groups [6].
Tobacco users are disproportionately more likely to be engaging in other modifiable risk behaviours such as excess alcohol consumption, physical inactivity, and poor diet [9]. A recent review identified strong associations between tobacco use and other modifiable risk behaviours [9], supporting an earlier report that only 12% of smokers had no other modifiable risk behaviours [10]. Tobacco users tend to consume more alcohol, eat less fruits and vegetables, and engage in fewer leisure time physical activity compared to non-tobacco users [11]. The clustering of these modifiable risk behaviours among tobacco users translates to a heightened risk for cardiovascular disease [12] and other chronic diseases may also negatively influence the likelihood of successful smoking cessation [13][14][15][16][17].
Methods to improve cessation rates are of utmost importance as the percentage of tobacco users who are able to quit and maintain abstinence unaided is low, estimated at 3-5% annually [18]. Identifying and implementing smoking cessation interventions that are holistic and address other modifiable risk behaviours may improve quit outcomes and enhance overall quality of life. A Cochrane review of interventions that targeted multiple modifiable risk behaviours (including smoking) estimated a net reduction in smoking prevalence of 24% [19]. However, older guidelines for smoking cessation traditionally recommended only focusing on smoking cessation [20][21][22][23].
While hundreds of interventions addressing the clustering of smoking and other modifiable risk behaviours have been conducted worldwide [12,[24][25][26][27][28], there is insufficient information available about what components of these interventions help to promote successful smoking cessation [19]. A rapid realist review, which emphasizes the mechanisms within the intervention that contribute to the outcomes and the context, can provide a more in-depth understanding of how and why interventions are successful or unsuccessful [29,30].
As a result, a rapid realist review was undertaken to analyze and characterize the various components of multiple health behaviour change interventions that contribute to the successful smoking cessation. The mechanisms within interventions were characterized using the Capability, Opportunity, Alliance. Picking Up the PACE aims to increase the capacity of practitioners to address other modifiable risk behaviours (e.g. physical inactivity, excessive alcohol use and poor diet) as a part of smoking cessation treatment. Picking Up the PACE aims to improve practitioner's capacity to address multiple health behaviours through two essential components: 1) developing an online training curriculum for healthcare practitioner outlining strategies and techniques for addressing multiple modifiable risk behaviours as a part of smoking cessation treatment and 2) designing a just-in-time clinical decision support system that will guide practitioners to address the engagement of multiple risk behaviours by their patients. The findings from this rapid realist review will also provide transferrable learnings for practitioners and decision-makers who are trying to develop multiple health behaviour change interventions.
In this paper, we report the findings of a rapid realist review of the current literature to produce a nuanced and critical understanding of the circumstances in which interventions for multiple modifiable risk behaviours increase smoking cessation outcomes. Specifically, the aim of this rapid realist review was to identify possible mechanisms used in multiple health behaviour change interventions (targeting tobacco and two or more additional risk behaviours) that are associated with effectively changing tobacco use.

Rationale for a Rapid Realist Review
Traditional approaches to literature reviews (systematic reviews and meta-analyses) assume outcomes are generated by linear causation [33]. While these approaches work well for studies conducted with highly controlled settings and exposures (e.g. randomized control trials); they severely limit our understanding of complex and pragmatic interventions [34]. Complex and pragmatic interventions require methods that offer a more comprehensive explanation of 'process' that was undertaken [35]. Therefore, a realist synthesis is well-suited to meet these needs as it is able to synthesize complex evidence from diverse sources to provide an understanding of what works in and intervention and how.
Specifically, a realist synthesis is a theory-driven approach for reviewing research evidence on complex interventions [29,30]. Its aim is to understand how, for whom, where, and why the intervention is effective or ineffective. This is accomplished by examining the "mechanisms"(M) (program theory), exploring the "contexts" (C) where the intervention occurred, and then linking these contexts and mechanisms to the "outcome" of the intervention (O) [29]. This is called a C-M-O configuration. Recurrent patterns of C-M-O configurations are known as demi-regularities, or semi predictable pattern or pathway of how a program functions. In other words, demi-regularities are a broad rule for how and when certain outcomes usually occur [29].
While full realist reviews can require a considerable time dedicated to the exploration of literature and subsequent analysis, rapid realist reviews (RRRs) have been used to enable a quicker transition from research to policy and/or practice [36]. Given the need for a timely synthesis and its application for the Picking Up the PACE programme, we undertook a rapid realist review; which allows us to maintain the core elements of the realist methodology and produce timely data.
Prior to this rapid realist review, a pre-specified protocol was registered (PROSPERO registration number: CRD42017064430) and published [37] which included the research question, search strategy, synthesis methodology, preliminary program theory, definitions, inclusion criteria for relevance screening, data extraction form, quality assessment tool, and plans for dissemination. An overview of the methods and any modifications to the original protocol are described below. Utilizing the RAMESES (Realist and Meta-narrative Evidence Syntheses: Evolving Standards) [38], and adapting it to follow a rapid realist review [35], the following steps were applied:

Clarifying the Scope
Identifying the research question. This rapid realist review supports a larger program, Picking Up the PACE, that aims to increase the ability of healthcare providers to offer evidence-based interventions to tobacco users which encompass changing modifiable risk behaviours (excess alcohol consumption, physical inactivity, poor diet, stress, and poor sleep) to ultimately achieve long-term smoking abstinence. As a result, these six risk behaviours are the focus of this review.
In order to clarify the scope of the rapid realist review, a multidisciplinary team with expertise in knowledge synthesis, public health, and multiple health behaviour change met in-person on nine occasions for 1 hour over the course of six months. Our initial research question was: "What factors are associated with effective multiple health behaviour change (three or more behaviours including smoking)?" Changes in the rapid realist review process. After a preliminary review of the data, further specificity of the study question was required to meet the desired outcome. Mechanisms involved in changing multiple health behaviours might be different than those involved in smoking cessation. Thus we modified our research question to: "What factors are associated with effectively changing tobacco use that target two or more additional unhealthy behaviours." Initial theory. We identified our initial theory of how, when, and why multiple health behaviour change As specified in our protocol manuscript [37], our preliminary review of these seven interventions involved having two independent reviewers extract the following information from the studies: The specific activities within each intervention. Activities are physical/tangible tasks that were undertaken by the intervention (e.g. , counselling, sharing of educational flyers, workshop, courses, prize draw).

2.
The setting in which the intervention took place, including physical environment, social setting, and political climate (if provided).

3.
The outcomes of each intervention, including any behavioural and/or clinical outcomes.
Through this preliminary review, we found two contextual factors that were common among successful interventions: pre-existing infrastructure that facilitates the delivery of the intervention, and targeting regions (e.g. geographic, population groups) where the need for the intervention is wellcharacterized. Furthermore, activities undertaken by these interventions often targeted the surrounding community and/or organizational structure. This multi-level approach appears to be in an effort to change the physical and social opportunities that can help facilitate multiple health behaviour change in individuals. Individual-level activities frequently focused on increasing patient's awareness and knowledge, improving feelings of support, empowerment, and incorporating incentives for completing activities.
Upon closer review, we realized that these activities mapped onto the COM-B model; which stipulates that behaviour change requires change in one or more of the following conditions: capability, opportunity, and motivation [31]. All seven studies used in developing our initial program theory sought to change at least one component of this behavioural system. We used the taxonomy of behaviour change techniques [32] to code each activity specified in the studies and we crossreferenced these codes with the COM-B model. We used Table 2  , an overall quality score was calculated for each study using the descriptors *, **, ***, and ****. For all types of studies, the score was derived by taking the number of criteria met and dividing it by the number of criteria. Scores were assigned the following descriptors: 0-25% (*), 26-50% (**), 51-75% (***), and 76%+ (****). To score the mixed methods studies, the overall quality could not exceed the quality of the weakest component of the study. For example, in a mixed method study, if the qualitative score is (**), and the quantitative and mixed method scores are both (***), the study is assigned an overall score of the lowest component (**).The questions used to score the studies can be found in Additional File 2.
Prior to data extraction and coding of the context, mechanisms, and outcomes within the studies, reviewers were trained on the COM-B model, the Behaviour Change Wheel and the BCT taxonomy [31,32]. They were also trained on how characterize the various techniques that are used within interventions and map these to COM-B model. Once trained, the following process was also undertaken by the two independent reviewers: · Review article to identify and record the activities that took place in the intervention.

·
Code the health behaviours the intervention was targeting.
· Code which techniques were applied to each activity, as defined by the BCT taxonomy. At each step, discrepancies between two reviewers were resolved by consensus or, when necessary, by a third reviewer.

Data Analysis and Synthesis Process
The data from DistillerSR Smoking cessation outcomes were measured in a variety of ways across articles, including different time points (e.g. at end of treatment, three months, 12 months), duration of abstinence (e.g. 7-day point prevalence abstinence vs last 30 days), and presentation of data (e.g. descriptive vs statistical analyses). These outcomes were verified (e.g. biochemically) or were self-reported. Both types of outcomes are valid [53-55] and therefore were not differentiated in this study. As a result, we organized our findings by whether statistically significant smoking cessation outcomes were observed and whether the outcome was measured long-term (i.e. five months or longer). Within these outcome types, the interventions were organized by the three categories that were then used to identify the mechanisms (capability, opportunity, and motivation) and the context in which the intervention occurred. Many of the reviewed articles did not describe the context in which the intervention was implemented in sufficient detail. Thus we decided to be as broad as possible, and included three different types of categories under context; 1) the continent in which the intervention took place, 2) the type of setting (e.g. clinical, workplace) and 3) whether it was a multidisciplinary intervention. We established the following criteria to report demi-regularities: · There were a minimum of three interventions using the specific C-M-O configuration.
· Among interventions with a specific C-M-O configuration, either more than 60% OR less than 40% of these interventions reported statistically significant increase in smoking cessation.
To present an example of how this process works, if we discover a C categorized as a demi-regularity, at least 60% of these interventions must report a statistically significant increase in smoking cessation outcome long term (5 months or longer. The demi-regularity in this case would be that interventions in clinical settings that target capability are more likely to lead to improvement in smoking cessation outcome. Alternatively, if 40% or less than 40% of the interventions report a statistically significant increase in smoking cessation outcome, the demiregularity would be that interventions in clinical settings that target capability are less likely to lead to improvement in smoking cessation outcome. In this paper, we analyzed demi-regularities in interventions that were rated four stars in our quality rating, used statistical analyses, and reported long-term smoking cessation outcomes (5 months or longer). We chose to only include those interventions with a four star rating as they have the least amount of bias. Once a demi-regularity was discovered, studies that had lower quality assessment scores (less than four stars), and/or did not perform statistical analyses were included in our pool for analysis to confirm if the previously observed demi-regularity persisted. [

Results
The flow of information through the rapid realist review process is shown in Figure 1. A descriptive overview of all the interventions is provided in Table 1. Exploration of the differences and commonalities among the interventions reveals several trends. For example, all interventions that took place in Africa (n=2) addressed only three behaviours and these behaviours did not include alcohol, stress, or sleep. Furthermore, none of the interventions in Africa use motivation as a mechanism. There was only one multiple health behaviour change intervention that took place in Central/South America (n=1). This intervention was conducted in a clinical setting and was designed to address four behaviours simultaneously. On the other hand, Europe (n = 60) and North America (n = 49) had larger variations in the number and types of behaviours addressed by any given intervention. Europe and North America were the only continents in which sleep was also targeted within behavioural change interventions. North America was also the only region in which there were interventions that targeted all six behaviours simultaneously.
Overall, the majority of interventions employed at least 2 mechanisms. Specifically 31(22%) interventions only used one mechanism, 66 (48%) of interventions used two mechanisms, and 41 (30%) targeted all three mechanisms. As shown in Table 1, 66 studies (48%) were scored as 4 stars, 59 (43%) were three stars, and 13 (9%) were scored as two stars. Common reasons for why studies scored less than four stars included: lack of clarity around whether bias was sufficiently addressed, use of non-validated measures, insufficient description of randomization process (if applicable), high withdrawal/drop-out.

Demi-Regularity -Opportunity
For the purposes of this rapid realist review, "opportunity" was defined as "all the factors that lie outside the individual that make the behaviour possible or prompt it" [31]. When interventions focused on increasing the "opportunity" to access services and change the social environment, tobacco users who engaged in other unhealthy behaviours were more likely to achieve long term smoking cessation. In particular, interventions that: 1) provided access to healthy living "tools" (e.g.
free medications such as nicotine replacement therapy, gym memberships, walking groups, free/accessible fruits and vegetables, etc.) and/or 2) encouraged social support (e.g. incorporating family members into care, interventions held social events). In various settings (e.g. clinical settings, community settings, workplace, etc.) and across several continents, programs that aimed to increase the opportunity to change behaviours were successful in achieving long term smoking abstinence among their participants (Table 3). These trends remain fairly consistent when examining all interventions; including those interventions that were rated from one to three stars in our quality assessment and reported statistical significance (see Additional File 3).
[ INSTRUCTION TO JOURNAL: INSERT TABLE 3] Demi-Regularity -Capability For this review, capability was defined as the "individual's psychological and physical capacity to engage in healthy behaviours" [31]. The success of interventions that included capability as a mechanism appears to be dependent on various factors, including: the specific context in which these interventions were implemented, the populations that were targeted, and the types of behaviours targeted in the intervention. When examining specific techniques for increasing capability, including "capacity to plan", "enhancing knowledge" and "empowerment", the effectiveness of these techniques is dependent on the context in which it is implemented.
Supporting evidence. Of the 53 interventions in our sample that were based on this mechanism [12,

Discussion
Health behaviour change programs that address multiple behaviours have been the subject of much discussion because there are a multitude of ways in which these programs can be developed, including: the types and numbers of modifiable risk behaviours to target [109], the types of activities to use [31], and the types of professions to involve [110][111][112] interventions that contribute to the outcomes of interest) lead to long-term smoking cessation.
The results of this rapid realist review emphasize the importance of incorporating mechanisms that modify external factors in multiple health behaviour interventions that attempt to achieve long term smoking cessation. Specifically, interventions that made resources (e.g. pharmacotherapy, exercise, healthy foods) more accessible, changed the physical environment (e.g. introduced smoke free polices), or increased one's social support network, were more likely to help individuals quit smoking.
Evidence to support these findings was noticeable across different regions, settings, and behaviours.
These findings challenge individualistic epidemiology that many health promotion interventions are based on, namely that health behaviours are a matter of individual choice [113]. consequences. These are all characteristics we identified and coded in each study and then grouped as "Capability" using the COM-B model's definition.
A major limitation of this review is that many of the articles reviewed did not describe the context or the behavioural change techniques used in detail. For example, we were unable to determine whether the setting in which an intervention took place already had other resources and supports that contributed to the success of the intervention (e.g. highly experienced staff). As a result, the contexts we were able to examine were broad, including: the continent in which the intervention took place and the type of setting (e.g. clinical, workplace). Given the wide variety in the types of populations that interventions targeted, we were not able to examine trends by target population.
Moreover, in some instances, the studies did not provide sufficient details on the types of activities It is important to also acknowledge that there were several challenges associated with isolating the mechanisms within the interventions. Specifically, for studies with poor quality reporting in articles, study design, and/or implementation, it was often difficult to determine which mechanisms were targeted. To get around this challenge, we reviewed articles with four star quality ratings first to determine the demi-regularities. However, these limitations also meant that, in some situations, we were unable to identify whether a specific mechanism was used. This may further contribute to underreporting of the mechanisms targeted within the interventions.
Lastly, the majority of interventions in this review targeted at least two mechanisms simultaneously (n = 97, 70%). It is unclear the degree of overlap between mechanisms and how these mechanisms interact to produce the observed outcome in these interventions. As a result, there may have been additional mechanisms and techniques that were employed by these interventions that we were unable to capture in our analyses. Future areas of research should also include examining the order in which behaviours should be addressed, (simultaneously vs sequential), the combination of behaviours to target, and the combination of mechanisms to target.

Conclusion
Our study is the first to apply a realist review methodology to explore how,

Consent for publication: Not Applicable
Availability of data and material: The datasets used and/or analyzed during the current study are available from the corresponding author on reasonable request.          b This category examines interventions that include the specific risk behaviour (i.e. alcohol) as one of the targeted behaviours. Figure 1 PRISMA flow diagram of articles through the rapid realist review process. aThere were a total of seven studies that were pre-identified for theory development; however one of the seven studies was published in 2013; which is within the timeframe for the literature search