Cigarette smoking is the leading preventable cause of morbidity and mortality in adults worldwide. ¹ Smoking is also among the prominent risk factors for disability-adjusted life years, ² and strongly associated with poor health-related quality of life. ³ The World Health Organization (WHO) estimates that 8.7 million people die prematurely worldwide each year, and tens of millions experience avoidable disease, due to tobacco use and exposure. ⁴ Tobacco-related disease and deaths are predicted to continue to increase globally in coming years. ⁵

Smoking-related harm places substantial strain on healthcare systems internationally, ^{6 , 7} and in some settings causes more disease and premature mortality than alcohol and illicit drugs combined. ⁸ In countries where tobacco is heavily taxed, smoking places economic burden on individuals and families due to the high cost of tobacco products, ⁹ in addition to lost wage-earning capacity from work absences and healthcare costs due to smoking-related morbidity, and premature death. ¹⁰

In 2007, the WHO introduced MPOWER measures as a guide to support countries globally to deter smoking. ¹¹ The acronym stands for the six measures included in the guide and are as follows: monitor tobacco use and prevention policies (M), protect people from tobacco smoke (P), offer help to quit tobacco smoking (O), warn about the dangers of tobacco (W), enforce bans on tobacco advertising, promotion and sponsorship (E), and raise taxes on tobacco (R). ¹¹

Many countries have established Quitlines, which offer telephone-based counselling services to support smokers to quit, ¹² fulfilling measure “O” of the MPOWER interventions. ¹¹ Whilst Quitlines have been shown to be effective and cost-effective internationally, ^{12 – 23} a preliminary search of the literature revealed heterogeneity between Quitline services by jurisdiction. Although there is evidence that engagement with a Quitline increases the likelihood of successful cessation attempts, ^{12 , 13 , 22 , 23} there is little evidence to support the specific components of Quitline services such as the optimum number, frequency or duration of counselling support calls, or core program components. ²² Furthermore, there is conflict regarding the benefit of free nicotine replacement therapy (NRT) provision as an adjunct to Quitline counselling. ^{13 , 23} The heterogeneity between Quitline services makes it difficult to evaluate the implementation of specific components and strategies used by each service.

Whilst there is ample literature evaluating the effectiveness of smoking cessation programs in community-based services, ^{24 – 34} the implementation of programs is rarely reported. Reporting core components of smoking cessation programs alongside implementation strategies, and implementation theories, models and frameworks will enable identification of the elements delivered that may be responsible for clinical or service outcomes, adaptations that have occurred across services that inform future selection of implementation strategies, and potential research gaps regarding program implementation.

Implementation Science facilitates the incorporation of evidence-based practices into routine healthcare by bridging the knowledge gap between research and practice. ³⁵

Interventions applied in controlled settings may demonstrate effectiveness. However, effectiveness is often not evaluated in real-world conditions prior to being integrated at the population level. ^{36 , 37} Evaluation of real-world implementation of interventions beyond the controlled research setting will demonstrate whether an intervention is effective when delivered to the intended populations and in different contexts. ³⁸ Real-world conditions refer to the context in which interventions are delivered by service providers to service users during usual care provision. ³⁹ In real-world implementation evaluations, factors that would be considered confounders within the research context, are considered part of the practical context in which the intervention takes place. ³⁷

Scoping reviews are a valuable tool for synthesising evidence, providing a broad map of existing literature and identifying gaps in current research. ⁴⁰ Scoping reviews are particularly valuable where the area of research is emergent, complex or poorly understood. ^{41 , 42} Using an existing scoping review framework, ⁴³ this study aims to systematically map the evidence including the effectiveness or perceived effectiveness of implementation, and any research gaps surrounding the implementation of smoking cessation programs.

The objective of this study is to systematically map the implementation of smoking cessation programs including evaluating how implementation influences service user outcomes.

The proposed scoping review will follow the Arksey and O’Malley ⁴³ methodological framework for scoping reviews. This methodological framework follows five key stages including firstly identifying the research question, followed by a literature search for studies that appear relevant to the research question, selection of studies for inclusion in the review through a literature screening process, extracting and charting data from the included studies, and finally, collating the results, summarising, and reporting the findings of the review. ⁴³

A preliminary search of PROSPERO, MEDLINE (EBSCOhost), Embase (Elsevier), Cochrane Central Register of Controlled Trials (CENTRAL), and JBI Evidence Synthesis (Ovid) performed on 23 January 2023 identified no existing or intended reviews on this topic.

This protocol outlines the methods for a scoping review evaluating the implementation of smoking cessation services in the community setting. The interventions included in this planned review were selected based on the smoking cessation interventions evaluated in contemporaneous literature. ^{32 , 59 – 64} Proctor et al. ⁶⁵ argue that implementation outcomes should be clearly distinguished from service system and clinical outcomes, to better evaluate the effectiveness of the implementation of services. The authors assert that this distinction between service and clinical outcomes, and implementation, is critical to understanding whether service failures are the result of ineffective interventions, or ineffective implementation. ⁶⁵ Milat et al. ⁶⁶ emphasise the importance of considering the implementation of interventions that historically, public health research has largely ignored. Implementation is an important consideration in research, as public health interventions may be effective within discrete, small-scale studies, but may not translate well in large scale to the general population. Glasgow et al. ⁴⁶ reiterate that implementation has frequently been ignored in public health literature, asserting that integrating an implementation framework into research would enhance the application and equity of intervention delivery to target populations.

This proposed scoping review will present an evidence map describing what is currently known, and knowledge gaps regarding the implementation of smoking cessation programs. A taxonomy of implementation theories, models, and frameworks used by smoking cessation programs will be produced, which may form the basis of future systematic reviews of the effectiveness of implementing smoking cessation programs. The outcomes of this scoping review may provide data to help inform the design of future smoking cessation studies. In addition, the results of this scoping review have the potential to contribute to smoking cessation service delivery and uptake.

RM designed and drafted the protocol and is guarantor of the review.

ZT provided substantial contribution to editing iterations of the protocol.

RM, ZT, KOG, DB conceived the study, contributed to the design and methods as well as edits to iterations of the protocol.