Background: Social media platforms are frequently used in health communication campaigns. Common understandings of campaign effects posit a sequential and linear series of steps from exposure to behavior change, commonly known as the hierarchy of effects model (HOE). These concepts need to be reevaluated in the age of social media, which are interactional and communal. Objective: This review aims to update the traditional HOE for health communication campaigns in the context of social media, including identifying indicators of effectiveness and how these are conceptualized to lead to health-related outcomes. Methods: We conducted a systematic review of studies following PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines reporting on the use of social media as part of health communication campaigns, extracting campaign information such as objectives, platforms used, and measures of campaign performance. We used these data, combined with our understanding of the HOE, to develop an updated conceptual model of social media campaign effects. Results: We identified 99 eligible studies reporting on 93 campaigns, published between 2012 and 2022. The campaigns were conducted in over 20 countries, but nearly half (n=42) were conducted in the United States. Campaigns targeted a variety of health issues and predominantly used Facebook, Twitter, Instagram, and YouTube. Most campaigns (n=81) set objectives targeting awareness or individual behavior change. Process measures (n=68; eg, reach and impressions) and engagement measures (n=73; eg, likes and retweets) were reported most frequently, while two-fifths (n=42) did not report any outcomes beyond engagement, such as changes in knowledge, behavior, or social norms. Most campaigns (n=55) collected measures that did not allow them to determine if the campaign objective had been met; that is, they were process evaluations only. Based on our review, our updated model suggests that campaign exposure can lead to individual behavior change and improved health outcomes, either through a direct or indirect pathway. Indirect pathways include exposure through social and policy changes. “Engagement” is positioned as critical to success, replacing awareness in the traditional HOE, and all types of engagement are treated as equal and good. No consideration is being given to potential negative engagement, such as the distribution of misinformation. Additionally, the process is no longer linear and sequential, with circular pathways evident, such as engagement not only influencing behavior change but also generating additional exposure to campaign messages. Conclusions: Our review has highlighted a change in conventional understandings of how campaigns can influence health outcomes in the age of social media. The updated model we propose provides social media campaigners with a starting point to develop and tailor campaign messages and allows evaluators to identify critical assumptions to test, including the role and value of “engagement.” Trial Registration: PROSPERO CRD42021287257; https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=287257

The Make Healthy Normal mass media campaign was a three-year campaign launched in 2015 in New South Wales (NSW), Australia to address community norms around overweight and obesity. It was underpinned by a hierarchy of effects model; a commonly used framework in campaigns but one that has rarely been tested. The campaign evaluation included a cohort study of NSW adults, surveyed three times over 12 months (n = 939 at Wave 3). This study tested the campaign's hierarchy of effects model, which theorized that participants would move from recognition to behaviour change via understanding, knowledge, attitude, social norms, self-efficacy, and intention, using these data. We used the moderation and mediation of effects method proposed by Baron and Kenny, adjusting for age and sex, to test for progression through the hierarchy of effects for two outcomes: physical activity and fast food consumption. We found a clear progression through the theorized model, from recognition through to behaviour change, via the intermediate variables for both outcomes. We also found several effects not predicted by the theorized model, with consistently strong associations between understanding and attitude, understanding and self-efficacy, attitude and self-efficacy, and self-efficacy and behaviour change in both outcome models. Our study provides support for the hierarchy of effects as a conceptual model in campaign planning and evaluation of social marketing campaigns. To our knowledge, this is the first study to compare the hierarchy between two behavioural outcomes and the consistency observed between the models adds to the potential usefulness of the hierarchy of effects.

Background: The literature on whole of system approaches (WSAs) has been largely theoretical in focus. The Australian Systems Approaches to Physical Activity is a national project designed to contribute a practical implementation focus to such approaches at the population level. Methods: National meetings were convened with federal and state government sector stakeholders to identify physical activity (PA) related policies and programs. Policies and programs were audited to develop an understanding of the existing PA system. A WSA conceptual map for PA was developed using feedback from system stakeholders, existing WSAs, and related work in obesity. Results: Completion of the policy audit has revealed key areas of need regarding policy governance, coordination, financing, and evaluation. An initial WSA conceptual map for Australia has been developed incorporating governance, translation, and advocacy. Stakeholder co-production of an integrated framework for PA and design plans for a community of practice knowledge hub has commenced. Conclusions: In Australia, Australian Systems Approaches to Physical Activity project partners have developed a conceptual whole of systems map that is guiding progress beyond the theoretical to application in the real world: a national PA policy audit, co-production of an integrated PA policy framework, and planning for a PA community of practice knowledge hub.

Background: Policies that support healthier food environments, including healthy retail food availability and promotion, are an important strategy for obesity prevention. The aim of this systematic review was to examine the evidence for barriers and enablers to successful implementation of healthy food and drink policies, delivered at scale. Methods: MEDLINE, SCOPUS and INFORMIT were searched to May 2019 for peer-reviewed studies. Google and Google Scholar were searched for grey literature. Studies of any design relating to a healthy food and drink policy delivered at scale (≥10 sites) in non-commercial food settings, for specific retail outlets (e.g., vending machines, cafes, cafeterias, school canteens), and that reported on implementation barriers and/or enablers were included. Studies in commercial food retail environments (e.g., supermarkets) were excluded. Studies were appraised for quality and key information was extracted and summarised. Extracted information on barriers and enablers was further grouped into overarching themes relating to perceptions of the policy itself, organisational and contextual factors influencing policy implementation, stakeholder responses to the implemented policy and perceived policy impacts. Results: Of 19 studies, 16 related to policies implemented in schools, two in hospital/health facilities and one in a sport/recreation setting. Most studies were conducted in North America or Australia, and policy implementation occurred mainly at state/regional or federal levels. The most commonly cited barriers across overarching themes and intervention settings were: lack of stakeholder engagement or prioritisation of the policy (11 studies); resistance to change from school stakeholders or customers (8 studies); and concern over profitability, revenue and/or commercial viability (8 studies). Few studies reported on mitigation of barriers. Enablers most commonly raised were: stakeholder engagement, whole-school approach and/or prioritisation of the policy (9 studies); policy level or higher-level support in the form of information, guidance and/or training (5 studies); and leadership, school/policy champion, management commitment and/or organisational capacity (4 studies). Conclusions: Key considerations for policy implementation ranged from building stakeholder support, prioritising policy implementation within organisations, to implementing strategies that address financial concerns and implementation barriers.

Background: Achieving system-level, sustainable ‘scale-up’ of interventions is the epitome of successful translation of evidence-based approaches in population health. In physical activity promotion, few evidence-based interventions reach implementation at scale or become embedded within systems for sustainable health impact. This is despite the vast published literature describing efficacy studies of small-scale physical activity interventions. Research into physical activity scale-up (through case-study analysis; evaluations of scale-up processes in implementation trials; and mapping the processes, strategies, and principles for scale-up) has identified barriers and facilitators to intervention expansion. Many interventions are implemented at scale by governments but have not been evaluated or have unpublished evaluation information. Further, few public health interventions have evaluations that reveal the costs and benefits of scaled-up implementation. This lack of economic information introduces an additional element of risk for decision makers when deciding which physical activity interventions should be supported with scarce funding resources. Decision-makers face many other challenges when scaling interventions which do not relate to formal research trials of scale-up; Methods: To explore these issues, a multidisciplinary two-day workshop involving experts in physical activity scale-up was convened by the University of Newcastle, Australia, and the University of Ottawa, Canada (February 2019); Results: In this paper we discuss some of the scale-up tensions (challenges and conflicts) and paradoxes (things that are contrary to expectations) that emerged from this workshop in the context of the current literature and our own experiences in this field. We frame scale-up tensions according to epistemology, methodology, time, and partnerships; and paradoxes as ‘reach without scale’, ‘planned serendipity’ and ‘simple complexity’. We reflect on the implications of these scale-up tensions and paradoxes, providing considerations for future scale-up research and practice moving forward; Conclusions: In this paper, we delve deeper into stakeholders’ assumptions, processes and expectations of scaling up, and challenge in what ways as stakeholders, we all contribute to desired or undesired outcomes. Through a lens of ‘tensions’ and ‘paradoxes’, we make an original contribution to the scale-up literature that might influence current perspectives of scaling-up, provide future approaches for physical activity promotion, and contribute to understanding of dynamic of research-practice partnerships.

Overweight and obesity in childhood and adolescence are associated with adverse health consequences throughout the lifecourse. Rates of childhood overweight and obesity have reached alarming proportions in many countries and pose an urgent and serious challenge. Policy responses across the world have been piecemeal. Evidence based policy actions and interventions are available to build a comprehensive approach to overweight and obesity but, in most countries, a narrow selection of interventions are chosen, often implemented over short time periods and typically with small-scale investment. The most cost-effective policy actions are rarely selected, or only partially adopted. Genuinely comprehensive, long-term population-wide approaches are scant. Leading-edge fiscal and regulatory strategies face aggressive, often effective, opposition from lobby groups. We outline the policy actions, governance and accountability mechanisms needed to tackle this global epidemic.