Chapter 3: Theory and evidence-based development of a weight loss intervention for
A. Overview
3.3 Discussion
This study set out to develop a weight loss intervention for overweight and obese primary school educators guided by the BCW. The Health4LIFE intervention is a behaviour change intervention targeting multiple behaviours, making it complex and challenging [Craig et al., 2008]. It is a self-help intervention consisting of a wellness day, a hard copy manual and text messaging. The intervention focuses on 13 behaviours related to dietary intake and physical activity, seven intervention functions (education, persuasion, incentivisation, training, environmental restructuring, restriction and enablement) and 21 BCTs (information about consequences of behaviour in general, information about consequences of behaviour specific to individual, goal setting (behaviour), goal setting (outcome), action planning, barrier identification or problem solving, set graded tasks, prompt review of behavioural goal, prompt review of outcome goals, prompt rewards contingent on effort or progress toward behaviour, prompt rewards contingent on successful behaviour, prompt self-monitoring of behaviour, prompt self-monitoring of behavioural outcome, provide information on where and when to perform behaviour, provide instruction on how to perform behaviour, teach to use prompts/cues, environmental restructuring, use of follow-up prompts, relapse prevention/coping planning, stress management, time management).
A major strength of the Health4LIFE intervention development process was the use of a comprehensive and coherent framework, namely the BCW, which is also underpinned with a behaviour change model (the COM-B model). The MRC guidelines of using a theory and evidence- based approach for intervention development was thus followed [Skivington et al., 2021; Craig et al., 2008.]. Unlike many other intervention development approaches, the steps of the BCW were found to be clear, detailed and systematic and facilitated its use, while providing a practical way of applying theory in the intervention development process in the present study. Each step was clearly outlined and was accompanied with a worksheet produced by Michie et al. (2015), which the developers completed as part of each task.
As part of the intervention development process, a group of experts in the field of research were identified to oversee and contribute expert inputs in the tasks executed. In total, there were eight panel members involved at various stages of the iterative process. Their inputs and experience proved to be invaluable, but the number of hours each member had to commit to the tasks they were involved in was considerable. Webb et al. (2016) also commented that a considerable number of hours had to be dedicated to the intervention development process by a much larger research team which consisted of 45 members.
When selecting the most appropriate intervention functions, BCTs, policy categories and the mode of delivery for the intervention, the BCW advises that the APEASE criteria are used [Michie et al., 2011a].
These steps required the use of judgement by the PhD candidate. As subjectivity can influence the
136 decision-making process during this stage it was helpful to confirm or revise the outcomes of these tasks as needed with the expert panel where their experience along with the appropriate evidence informed the judgement calls. Mabweazara et al. (2019) also mentioned the judgement calls when using the APEASE criteria as a limitation in the development of a physical activity intervention for people living with Human Immunodeficiency Virus (HIV) and Acquired Immunodeficiency Syndrome (AIDS). It is therefore recommended that an experienced panel is involved in applying the APEASE criteria, rather than on individual only. It is also recommended that these decisions are supported by appropriate evidence, including having in-depth knowledge and understanding of the target population and environment.
Once the capability, opportunity and motivation requirements to achieve a desired target behaviour had been analysed, the BCW easily linked the intervention functions and BCTs. Linking the COM-B model to the relevant intervention functions and then the BCTs was found to be seamless and although firmly grounded in theoretical behaviour constructs, its use did not require in-depth knowledge of behaviour change theory. These were also the findings of two other intervention designers who used the BCW to develop interventions aimed at improving dietary intake and physical activity for type II diabetics [Moore et al., 2019] and improving physical activity in people living with HIV and AIDS [Mabweazara et al., 2019]. The fact that the BCW utilises a standardised coding for its BCTS, namely the BCT taxonomy [Michie et al., 2011c], improves replicability of the intervention, as well as the evaluation thereof.
The comprehensiveness of the BCW made the process of using it labour-intensive and time- consuming. Stage 1 of the BCW involved four steps which aimed to increase understanding of the behaviour. This entire stage, especially using the COM-B model, required extensive formative assessment, which involved reviewing existing research for identification of target behaviours for weight loss in primary school educators. Focus group discussions were also conducted to identify salient beliefs regarding dietary intake and physical activity in the same group of educators. However, as the COM-B model is the core of the BCW and informed a better understanding of the 13 target behaviours, while identifying what needed to change for a behaviour to occur, this stage of the process could hardly be neglected. This is especially true for educators as existing literature on weight loss needs of interventions of this target group in South Africa and in the rest of the world was extremely sparse when the intervention development process commenced. The four steps in Stage 1 may seem repetitive, as each step must be repeated for every identified target behaviour. This was especially prominent in the development of the Health4LIFE intervention with 13 target behaviours to address.
It is interesting to note that some studies skipped steps 1 to 3 completely, presumably to shorten the process, as the research teams felt that the target behaviours of their specific interventions were already well understood in existing literature [Murtagh et al., 2018; Webb et al., 2016].
137 The BCW was found to be expandable and did not restrict and limit the development process. It allowed for the integration of the TPB [Ajzen, 1991], and the HBM [Rosenstock et al., 1988;
Rosenstock, 1960, 1966, 1974; Hochbaum, 1958] and use of the SatMDT [Lewis et al., 2016] in the development process, thereby strengthening the theory component and making this research unique in its approach. Using the TPB allowed a greater and deeper understanding of educator beliefs regarding their dietary intake (fruit, vegetables, fat and sugar) and physical activity by identifying which belief required reinforcement or changing. This information was used when completing the COM-B model, specifically when reflective motivation was being analysed as part of the behavioural analysis process. Belief results were subsequently also used during the message development phase to ensure effective and targeted messaging. As there is a paucity of information on beliefs educators hold relating to healthy lifestyle behaviours, there was great value in identifying these beliefs and integrating the information as relevant in the BCW steps. Research where integration of belief assessment in this manner in the intervention development process could not be traced, with this research thus making a novel contribution in this regard.
The HBM advised the development of the first element of the intervention, namely the wellness day.
The importance of creation of health awareness among educators is emphasised by the findings of Senekal et al. (2015} that many educators were likely to underestimate their body weight. Health screening has good potential to create awareness, especially if it includes assessment, interpretation and feedback on a range of measures such weight status and NCD risk indicators such as blood pressure, glucose and lipid levels. Awareness creation effects of health screening among educators in Cape Town has been illustrated by Joseph et al. (2018) in this regard.
The BCW does not provide guidance as to how to translate the BCTs into text messaging features and it therefore became necessary to expand on the BCW again. The SatMDT [Lewis et al., 2016], which was specifically designed to guide the development and evaluation of health messages was therefore incorporated into the BCW. It is underpinned by the TPB but also considers the impact of individual characteristics of participants and message-related characteristics on the effectiveness of messages [Lewis et al., 2016]. It provided very clear guidance how to develop targeted messages that were appropriate and effective using a structured process. The messages could be related to an outcome, a BCT and a belief. The text messages and the manual content were checked to ensure they complimented each other. Curtis et al. (2015) developed a weight management app for the parents of overweight children and also had to expand the BCW when it failed to provide guidance on translating BCTs into mHealth app features. Although the theory component of the intervention development process was strengthened using the SatMDT, this process was further time-consuming to an already lengthy process.
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