Abstract: Background and Objective: Childhood obesity is a global epidemic. While childhood obesity intervention programmes have been developed and implemented, few studies have investigated the sustainability of these programmes. This systematic review explored the sustainability of childhood obesity interventions at the individual, interpersonal, organizational, community and public policy levels of the Socio-ecological Model (SEM). Materials and Methods: A keyword search was conducted using the online databases EBSCO, PubMed and Science Direct. The inclusion criteria were primary research, long-term childhood obesity interventions (at least 12 months) with a follow-up of at least 6 months after the end of the intervention, overweight or obesity interventions implemented from 2007 until June 2018 and English as the reporting language. Results: These systematic searches found 1953 studies but only eight met the inclusion criteria. Factors such as programme champion, system/policy, workforce, community capacity, engagement/relationship building, adaptation/adoption, evaluation and feedback, training and education, collaboration and partnership as well as ongoing support contributed to the sustainability of the programme. Conclusion: It is important that future research assesses the sustainability of childhood obesity interventions, particularly at the public policy level. Attention should be given to enhancing sustainability in future intervention studies.
INTRODUCTION
According to a World Health Organization report1 published in 2016, the number of obese children and adolescents has increased tenfold globally in the past 40 years. A study published in the Lancet found that from 1980-2013, the worldwide prevalence of childhood overweight and obesity increased by 47%2. In Malaysia, the South East Asian Nutrition Surveys (SEANUTS), conducted from 2010-2011, reported that among urban children aged 7-12 years3, 14.4% were overweight and 20.1% were obese. Overweight and obesity were estimated to cause 3.4 million deaths, 4% of disability-adjusted life-years (DALYs) and 4% of years of life lost worldwide in 20104. In addition, overweight and obesity during childhood are known to have implications for both physical and psychosocial health. Moreover, it has been reported that the risk of persistence of overweight and obesity from childhood to adulthood was high and that obesity increases the burden of cardiovascular disease5.
While many public health studies have focused on determining the factors that are critical for successful implementation6, little attention has been paid to the aspects that impact the sustainability of these programmes. Furthermore, many health intervention programmes have not been studied in terms of their sustainability. As reported by Gruen et al.7, sustainability issues in health intervention programmes are becoming increasingly important to funders, programme managers and decision and policy makers who often face challenges in sustaining health intervention programmes and are concerned about the long-term impact of their investments. While numerous factors contribute to the successful implementation of these intervention programmes, the effects of these programmes may diminish over time8-10. After an initial period of support, many intervention programmes are terminated because of financial limitations and a lack of human resources. If more attention was paid to sustainability issues, such unfortunate results could be avoided.
After examining different definitions of sustainability, Shediac-Rizkallah and Bone11 proposed three indicators of sustainability: (1) Continued health benefits for participants after the termination of programme funding, (2) Continuation of programmes within an organization, often referred to as ‘institutionalization’ or ‘routinization’ and (3) Continuation of community capacity by developing processes to deliver programmes in a community. Sustainability can also be defined as the ability of a programme or intervention to be institutionalized within an existing government or community setting12.
While systematic reviews of many aspects of childhood obesity are now available for example, the two landmark reviews in the Cochrane Library, namely, Interventions for Preventing Obesity in Children13 and Interventions for Treating Obesity in Children14, there are, to date, no systematic reviews on the sustainability of childhood obesity interventions according to the Socio-ecological Model (SEM).
Understanding the factors that impact the sustainability of childhood obesity intervention programmes is vital to the durability of these programmes15. Even if the implementation of an intervention is successful, it may not necessarily develop as intended16. Interventions conducted over one school year or longer appear to be more sustainable17,18. Hence, to better understand the sustainability of childhood obesity intervention programmes, this systematic review considered data from interventions that lasted 12 months or longer. This duration was chosen because, as shown by Ickes et al.19, interventions of more than one year correlate with positive BMI improvements and are more likely to be sustainable at different levels of the SEM.
This systematic review focused on the SEM developed by McLeroy et al.20. There are five levels of influence for health-related behaviour: (1) Individual factors such as the continuation of health benefits, beliefs, attitudes and knowledge, (2) Interpersonal factors (family, peers and friends), (3) Organizational or institutional factors for social institutions, such as schools and health care organizations, (4) Community factors for relationships among organizations, neighbourhoods and parks and (5) Public policy factors for local and state policies 20.
This systematic review aimed to investigate the level of sustainability of childhood obesity interventions and to identify the factors that influenced the sustainability of the intervention programmes.
MATERIALS AND METHODS
Data sources: A comprehensive literature search was performed using three electronic databases PubMed, Science Direct and EBSCO (Medline Complete) for the period from 2007-2018. The following keywords and their variations were used as search terms: ‘sustainability’, ‘institutionalization’, ‘children’, ‘adolescent’, ‘youth’, ‘intervention’, ‘programme’, ‘program’, ‘project’, ‘overweight’ and ‘obese’.
The search strategy was based on the following components of ‘population, intervention, comparison and outcome’ (PICO): population (0-18 years old, children, youth or adolescents); intervention (obesity/overweight interventions published between 2007 and June 2018, non-pharmaceutical-based interventions, intervention of at least 12 months); comparisons (with or without control group); outcomes (more than 6 months of follow-up after the end of the intervention, reporting sustainability outcomes). PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines21 were used for the reporting procedures.
Study selection: The inclusion criteria were developed and applied by two researchers separately for study selection. Two researchers independently conducted the search and a third researcher helped to resolve any disagreements concerning the inclusion and exclusion criteria. To be eligible for inclusion in the review, studies had to consist of primary research published in the English language between January 2007 and June 2018. We reviewed studies that examined sustainability outcomes, such as the continuation of some components of programmes or the desired outcomes that were sustained after the initial implementation. Studies were excluded if they (I) Included a pharmaceutical-based intervention, (ii) Involved interventions of less than 12 months in duration and (iii) Did not report sustainability outcomes.
Data extraction: A standard data extraction form was used to populate the evidence tables and to cross check for agreement and accuracy. A priori coding was created beforehand and applied to the text during data analysis. The extracted items for the evidence tables were programme champion, system/policy, workforce, community capacity, engagement/relationship building, adaptation, evaluation and feedback, training and education, collaboration and partnership and ongoing support.
RESULTS
Our systematic search found 1953 studies (Fig. 1) after a comprehensive literature search. After screening the titles and abstracts, 40 potential papers were retrieved. Of these, seven papers were eligible for inclusion. Forward and backward citation searches were applied to all eligible studies and an eighth eligible paper was identified from this forward and backward citation searching process. The reasons for exclusion and the study flow are reported in Fig. 1. Disagreements were resolved through discussion and, when required, referred to a third researcher. Table 1 summarizes the study characteristics and main findings of the eight selected interventions. Table 2 provides an overview of the sustainability variables and the SEM level targeted by interventions in the eligible studies. Table 3 shows a summary of the sustainability outcomes.
Sustainability at the individual level and intrapersonal level: The continued health benefits, such as anthropometric outcomes, were assessed in the eligible studies. All of the interventions that were conducted ranged from one year and six months to four years and four months in duration. The involvement of individuals, specifically children, in interventions was mentioned by all of the eligible studies22-29.
| Fig. 1: | PRISMA (reference) study flow diagram |
| Table 1: | Summary of study characteristics and main findings of the eight selected interventions |
| Table 2: | Variables related to sustainability with Socio-ecological Model (SEM) levels targeted by interventions in the eligible studies |
| Level 1: Individual, Level 2: Interpersonal, Level 3: Organizational, Level 4: Community, Level 5: Public policy | |
Most of the studies (n = 4) reported lower increases in body weight and BMI z-scores among children in the intervention group22-25 than among children in the control group. Four studies23,26-,28 reported that the physical activity level of the children increased after the interventions. Children significantly improved their academic achievement after intervention in one study23. Teachers reported that healthier food and drink consumption by students at school were higher after programme implementation28. One study27 reported that the nutritional knowledge of the students improved after intervention. Another study23 identified a positive change in children’s attitudes and beliefs towards physical activity fostered by the intervention. The sustainability of increased physical activity in this case could have been due to changes in the children’s attitudes and beliefs that were brought about by the intervention.
The interpersonal level in the SEM refers to the communication between several individuals such as the involvement of programme champions, the workforce from interventions, the engagement and relationship building with school teachers, parents, healthcare workers and community members, the evaluation to measure the effectiveness and intervention strategies and the training and education for school teachers, parents and healthcare providers to deliver intervention programmes.
In the Physical Activity Across the Curriculum (PAAC) intervention by Donnelly et al.23 and a study by Schetzina et al.28, programme champions were school teachers. Teachers who taught the classes championed the programme and their participation in physical activity at school facilitated behavioural change among school children23, while another study28 indicated that school teachers championed the intervention by serving as role models for active living and healthy eating.
Five studies mentioned workforce in the interventions23,24,26-28. Three studies23,26,28reported the participation of school teachers in classroom physical activities and physical fitness. Healthcare staff were highlighted by two studies27,28 in interventions to provide information on children’s weight status to parents after screening and diet consultations to parents. The involvement of parents was also important, as reported in two studies27,28. Parents play a role in following recommendations for creating healthier school environments28 and are also important in providing knowledge related to nutritional and physical activity to children27.
Over half of the studies reviewed highlighted engagement and relationship building at the interpersonal level22-27,29, where the engagement and relationship building included consultative decision making involving stakeholders22, school administration and teachers23,26, local priorities26,27,29, healthcare professionals22,24, and nonprofit organizations25,26.
Although, eight studies were included in this review, only five studies were able to link evaluation to the sustainability of interventions programmes23,25,27-29. Donelley noted that extensive process evaluation measures were collected to monitor the teachers in delivering the lessons as planned23. One study reported feedback of healthier consumption of foods and drinks by students28, which is similar to a study that acknowledged an improvement of lifestyle programming for pre-school children and parents29. Two studies conducted evaluation measures on weight status and fitness27 and tracked logs to evaluate staff surveys monitoring implementation fidelity and sustainability of intervention25.
Training and education were cited as important in the implementation and maintenance of interventions23-25,27-29. Four studies reported that training was given specifically to school teachers23,24,,27,28 by research assistants, exercise specialists or dietitians prior to intervention implementation. Training was also provided to office staff throughout the intervention approach for obesity prevention25.
Sustainability at the organizational level: The sustainability of interventions at the organizational level based on the SEM model refers to interventions that are organizational-based, such as those at school.
| Table 3: | Detailed sustainability components and outcomes of each eligible studies |
School teachers are identified as programme champions23,28 as they act as role models for delivering lessons after the completion of interventions. Of three studies that discussed policy or system linked to sustainability, two studies24,27,28 acknowledged that policy assisted with sustainable changes to healthier food environments within school settings promoted the sustainability of interventions by implementing new guidelines and school policies. The workforce involved in the organizational setting, namely, school teachers and school staff, was mentioned by three studies23,26,28. Training and education, as well as engagement and relationship building with school administrators and school teachers, were performed to ensure sustainability of the interventions23,28.
Adaptability or adoption of intervention components to organizational context were discussed in two studies23,28. The PAAC23 was sustained as school teachers were identified as the programme champions that facilitated the adoption, implementation and execution of the programme. One study28 found that the intervention was adopted by making CDs or DVDs of the intervention available for teacher use in the classroom as a teaching tool. It was promising that the schools in PAAC23 accepted the principles of a childhood obesity intervention programme and that the intervention was integrated with existing curricula at the school.
The effort required to establish effective collaboration and partnership was acknowledged in organizational settings. Collaboration with other organizations such as Parent Teacher Associations (PTA) and exercise specialists promoted the sustainability of the intervention28. One study24 reported that collaboration with a dietitian in this school-based intervention showed the significant role of health advocates. These changes need to be supported by changes in the environments and social norms that support positive health decisions to facilitate the behavioural change of students to drive sustainability efforts. Ongoing support from these partners is required to sustain the success of partnerships at the organizational level. Two studies highlighted the continuous support received from PTA28 and parent donations24 to maintain the programme.
Sustainability at the community level: A workforce at the community level, including public health professionals, educators, healthcare providers and parents, was mentioned by one study27. Partnerships with health and literacy advocates were established to reduce television screening time. Five studies22, 25-28 discussed community capacity building, whereby individuals or community members obtain and retain the skills or knowledge from the interventions to archive sustainable results. Community ownership was cited as important in community capacity building, in which existing resources were community-oriented as the intervention was fully operated and owned by the community22. Integrating partnership from health advocates and the community in the implementation of interventions increases the likelihood of sustainability, as community members feel more ownership than they would if the intervention did not include them27.
Five studies22,24-26,29 reported engagement and relationship building at the community level with stakeholders, agencies, city departments and nonprofit organizations to lead the programme implementation. Partnership and collaboration with other organizations and some public community centres that provide physical activity access were selected to reinforce and utilize the facilities to promote healthy lifestyles and physical activity29. One study also highlighted the approach of engaging partners and incorporating local priorities to enhance community capacity building that led to the sustainability of the intervention. New partnerships were identified that were likely to support the previous work and champion the programme, which further supported the goal of the intervention to promote healthy weight and prevent childhood obesity with the involvement of the community27.
The adaptability and adoption of interventions at the community level was discussed in two studies22,25. One study22 reported that the intervention was neither adopted nor adapted but the intervention activities were designed to be transferable to other communities as it was delivered through fairly standard methods. Meanwhile, another study25 showed that the intervention was also adopted and adapted by nationwide providers.
Sustainability at the public policy level: Interventions can be sustained at the public policy level by working with city departments on health policies that influence children during and after school to provide consistent healthcare services27. A positive change in attitudes or behaviour about policies that promote physical activity and a healthy eating environment can influence people’s practices. Policies are often the driving force behind systematic change that facilitate behavioural change.
DISCUSSION
To the best of our knowledge, this is the first systematic review that explores the sustainability of childhood obesity intervention programmes at different levels of SEM. The eight studies identified in this review found that long-term interventions (at least 12 months in duration) with factors that enhance sustainability were successful in reducing BMI z-scores, increasing levels of physical activity and lowering waist circumference.
Schools are viewed as the key setting for obesity prevention, as they provide the opportunity for children to undertake physical activity and learn about healthy eating behaviours. An intervention study known as The Malaysian Childhood Obesity Treatment Trial (MASCOT) found that obese children in the intervention group spent 89% of their waking hours on sedentary activities30. Therefore, school environments can promote physical activity and healthy eating, which influences a child’s health31. Benjamin and Whitman24 reported that a project’s dietitian created a supportive environment in school, which promoted healthy eating and facilitated positive behavioural changes in students. A systematic review by Clarke et al.31 also reported that stakeholders emphasized the importance of multiple physical education (PE) sessions, afterschool programmes, lunch-time activities and increased movement during classes. Therefore, it is important to involve stakeholders in programme planning prior to an intervention to ensure community empowerment and to develop capacity building32 to enhance sustainability.
In this review, however, there were only two school-based interventions that aimed to increase physical activity to reduce gains in BMI23 and to evaluate the knowledge, attitudes and behaviours among school children24. Children who are more physically active are more likely to have lower BMI and body fat percentage as well as waist circumference than their less physically active cohorts33. Teachers and parents can coordinate with the school principal, canteen operators and students to organize available resources to institutionalize the practices, which will promote sustainability. A study in 2018, namely, the Juara Sihat intervention, was a 12-week school-based obesity intervention conducted at a primary school in Kuala Lumpur, Malaysia to improve anthropometric status and physical activity level among overweight and obese primary school children. This study reported that the involvement of school teachers and the PTA in the intervention helped change the children’s behaviour to eat healthily and to be more physically active34. The PTA played an important role in strengthening the relationship between school teachers and parents, which in turn provided strong social and peer support to all participants throughout the intervention. Empowering parents to participate in an intervention is also an effective way to manage childhood obesity35.
When intervention programmes involve stakeholders, the coordination and partnership of the agencies involved are critically important for successful implementation and sustainability6. The coalition of stakeholders and agencies can engage people, ideas and resources across sectors and settings to create programmes with long-term impacts on peoples’ health36. In the PAAC study, many teachers used the intervention module at school at least one day per week, even after the intervention ended. This observation supports and extends the results of other studies that found that integrating activities within existing programmes and involving stakeholders in organizing the programmes are more likely to be sustained in the long run37,38. Donnelly et al.23 and Schetzina et al.28 also reported that the PAAC programmes were successful because they cultivated a programme champion (a school teacher) and they were consistent with the schools’ values. The identification of a programme champion someone who is strategically placed in an organization to support and promote the programme is crucial to the sustainability of the programme39. One study showed that it was crucial to have a programme champion; otherwise, the partnership between the organization and its programme manager would have collapsed40. Polacsek et al.25 illustrated how an overweight intervention programme targeting Maine youth was institutionalized, from the adaptations made by providers nationwide to its dissemination by the National Cancer Institute Research-Tested Intervention Programmes (RTIPs) and others25.
According to Harris and Sandor, the four features of sustainable practice in community-based intervention programmes include (1) Effective relationships and partnerships, (2) Evidence-based decision making and practice, (3) Building of community capacity and (4) supportive context for practice41. The eight eligible studies showed that the building of community capacity, in collaboration and partnership with stakeholders, seemed to have significant potential to slow weight gain in children22,23,25-27,29. The development of community capacity and relationships among community members enhanced community ownership, which, in turn, increased capacity and promoted programme maintenance. The engagement of partners, the recognition of local priorities and the use of strategic resources further enhanced community capacity. These findings suggest that the involvement of participants from a community positively affects the sustainability of an intervention.
Choosing an appropriate timeframe after an intervention ends is important when evaluating its sustainability. Although, there is no specific timeframe that defines an intervention as sustained, it is useful to separate the implementation period from the post-implementation phase. Most of the studies in this review had a duration between one year and six months to four years and four months, which is consistent with suggestions in the literature regarding the duration needed to assess sustainability and the factors that influence it42.
Research on the sustainability of childhood obesity interventions should move in the direction of applying sustainable components to ensure that the impact is felt over time. This review provides some evidence supporting the sustainability of an extended childhood obesity intervention. In some of the eligible studies, the participants continued to receive health benefits after the programme’s initial funding had ended and /or the intervention programme was continued within the organization (institutionalization) and /or there was evidence of a continued community capacity to deliver programmes after the initial research programme had terminated. In addition, we also found limited evidence on sustainability at the public policy level. We believe that a sustained healthy behaviour intervention may also be related to the implementation strategies or integration with local practices at the organization level and community level.
This review considered the sustainability of childhood obesity intervention components and the need for future research on the sustainability of childhood obesity interventions. Sustainability may be enhanced at the individual level by targeting a child’s knowledge, attitude and practices that lead to behavioural change. This review is very important, as the researchers revealed the critical areas of childhood obesity interventions leading to sustainability that many researchers did not explore. The influence of parents on the sustainability of childhood obesity interventions in the home environment should also be considered.
LIMITATIONS AND STRENGTHS
The present study and the previous studies reviewed have several limitations and strengths. Most of the studies identified in our search results were excluded due to the short duration of the interventions and a lack of reported sustainability outcomes. It is likely that many studies of intervention programmes did not attempt to determine the extent to which the interventions were sustained after the studies ended. Although, we attempted to identify studies using multiple search strategies, the range of key words related to sustainability used in the search may have limited the scope of the review.
Despite these limitations, the strengths of our review include that we addressed a novel and important topic and applied double-screening to determine study eligibility. Data extraction and quality appraisals were also independently checked by two reviewers. Quality appraisals were performed by preliminary synthesis by two reviewers who described each of the studies, summarized the same features for each study and tabulated results in order to identify patterns across the included studies. This review identified the factors which impacted the sustainability of intervention programmes using the SEM. Information from this review will help researchers and stakeholders who wish to develop and implement sustainable health intervention programmes.
CONCLUSION
This review found limited data on sustainability of childhood obesity intervention at various levels of the SEM. Overall, there is emerging evidence that factors such as programme champions, community capacity, engagement and relationship building, programme adaptation and training may contribute to the sustainability of the programme. However, attention should be given to enhancing sustainability for longer durations in future intervention studies. Future research is warranted especially on assessing the sustainability of childhood obesity interventions, particularly at public policy levels.
ACKNOWLEDGMENT
We thank Professor John Reilly from the University of Strathclyde for providing an attachment and to Universiti Kebangsaan Malaysia for supporting this study. This study is part of the Juara Sihat programme funded by Danone Dumex (M) Sdn Bhd research grant (Project Code: NN-068-2013).