Promotion of healthy behaviour and prevention of obesity in workers with a lower socioeconomic position: an equity specific analysis of what works and why

PROBLEM DEFINITION Unhealthy behaviour and obesity contribute substantially to socioeconomic health inequalities in the working population. Lifestyle interventions in the work setting seem particularly promising to contribute to the reduction of these inequalities, because they can target those in lower social groups directly, and because of the ability to combine environmental and individual determinants. Yet, and despite an urgent call from policy makers and employers, little is known how to do this effectively. Over the past years, many interventions in the work setting for workers on promotion of healthy behaviour and obesity prevention have been conducted. Previous studies suggest that (inter)national lifestyle interventions are mainly effective among workers with a high socioeconomic position (SEP). However, it is unknown whether these socioeconomic differences also hold for lifestyle interventions in the Dutch context. This raises the questions whether the lifestyle interventions themselves are (in)effective for workers with low SEP or that those workers are less compliant to the interventions. And which intervention characteristics (e.g. content, duration) and work context (e.g. company size, social support) influence the effectiveness and compliance among workers with low SEP. We will integrate the findings of high quality studies on the effectiveness of Dutch intervention studies aimed at promoting healthy behaviour and obesity prevention. This meta-analysis will provide this knowledge and thereby contribute to developing and implementing effective interventions among workers with low SEP to reduce socioeconomic health inequalities. META-ANALYSIS OF DUTCH LIFESTYLE INTERVENTIONS The proposed study will re-analyse a broad range of existing Dutch interventions aimed at promoting healthy behaviour and obesity prevention among workers with low and high SEP separately. In a pilot study, principal investigators of 15 eligible Dutch studies were approached and informed about the proposed project, were asked if their evaluation studies included an indicator of socioeconomic position and if they were willing to participate in the project. This pilot showed that data of at least 12 studies is available, and they showed all great willingness to participate in the project. The study consists of four steps. First, we will conduct subgroup analyses to SEP for each study separately, following guidelines on the definition of SEP and outcome measures. The results will be visualized by harvest plotting for different socioeconomic groups. Studies will be classified in one of three groups: a negative social gradient (intervention more effective in lower socioeconomic groups), no gradient, or a positive gradient. Harvest plots will be made for different outcomes of healthy behaviour. Second, as obesity measures (BMI and waist circumference) are assessed identically across the majority of the studies, we will evaluate the effects on obesity by pooling the individual data of these studies and investigate the effects and moderators (education level) of the interventions on these outcomes. If significant interaction effects will be found, then stratified analyses will be carried out. Third, we will investigate the impact of the Dutch work context and intervention characteristics on the effectiveness of the intervention workers with low SEP in both step 1 and step 2. Lastly, as workers with low SEP seem less willing to participate in the interventions, this step will provide knowledge about the compliance of workers with low SEP based on data retrieved from existing process evaluations. And we will study whether intervention characteristics and work context can contribute to higher compliance. The results from this project will provide scientifically solid, practical guidance as to how to develop effective lifestyle interventions for workers with low SEP as well as how to implement and deliver the interventions to these workers. KNOWLEDGE TRANSFER According to the needs assessment among the most important stakeholders (companies, sector organizations, representatives of occupational physicians and a public health service), there is a wide recognition of the added value for practice of knowledge that will be obtained from this project. Moreover, we will translate preferences and needs into tailored materials for the stakeholders (e.g. MOOC and factsheet) and the target group of workers with low SEP (e.g. infographic). Involvement of the stakeholders is ensured by NSPOH as project member as well as by organizing meetings during the project with the above described stakeholders. EXPERTISE OF THE RESEARCH GROUP The consortium members have extensive and documented experience in research on socioeconomic inequalities, interventions on preventing unhealthy behaviour and obesity and conducting meta-analyses. Participation of NSPOH will ensure knowledge on dissemination and education in occupational health setting.