Study protocol: a cluster randomized controlled trial to assess the effectiveness of a multi-pronged behavioural intervention to improve use of personal protective equipment among migrant workers exposed to organic solvents in small and medium-sized enterprises

A healthy workforce is essential for productivity and economic development [1, 2]. However, the burden of work-related diseases and injuries was high in developing countries. An estimated 2 million people die each year from work-related diseases causing an economic loss of about 2.8 trillion USD annually, or 4.0 % of the global gross domestic product (GDP) [3]. In these countries only 5 %–10 % workers have limited access to basic occupational health services aiming for the primary prevention and control of occupational and work-related diseases and injuries [4, 5].

In China, rapid industralisation has been associated with the rapid increase in internal population. Most of the migrants work in the small and medium-sized enterprises (SMEs), contributing to the tremendous economic development, but also exposed to great occupational risks and hazards. In China, the number of reported cases of occupational diseases have increased from 11,718 in 2000 to 29,972 in 2014, with an annual growth rate of 7.0 % [6, 7]. The majority of victims were migrant workers in SMEs [8]. It is estimated that about 100 million migrant workers in SMEs were exposed to occupational hazards [9]. However, due to their limited education, migrant workers tend to have poor occupational health knowledge, attitudes and behaviours. Lack of use of personal protective equipment (PPE) makes them prone to occupational diseases. Previous studies showed that among migrant workers in SMEs, only 16.8 %–22.4 % have used PPE effectively [10, 11]. There is an urgent need to improve the use of PPE, as a primary prevention to protect workers against occupational hazards, among migrant workers. Organic solvents rank as the top cause of chronic occupational poisoning, which is the second most common occupational disease in China [7, 8]. In this study, we aim to design a multi-level behavioural intervention to promote PPE utilization among migrant workers in SMEs who are exposed to organic solvents.

Behaviour change cannot be achieved without first recognizing and understanding the complex factors that affect behaviours and the mechanisms by which migrant workers change and maintain their behaviours. Behavioural change theories, such as the Health Belief Model [12], Bandura’s Social Cognitive Theory [13], and the Theory of Reasoned Action [14], and Andersen’s Behavioral Model of Health Services Use [15], highlight the interaction of individual and contextual factors to influence the process of human behaviour change and health services use. In terms of workers’ PPE utilization, factors influencing the behaviour at the individual level include demographic characteristics [16], health education and awareness [17, 18], attitude towards the behaviour [19], self-efficacy, perceived benefits and barriers [16] and interpersonal factors [20]. At the organizational context level, factors can include implementation of regulation and occupational health service provision [21, 22] and an enabling environment to allow for effective PPE utilization behaviour [20]. Combining the factors at the individual and organizational levels, and based on behavioural models mentioned above and our exploratory study on the occupational health of migrant workers [10, 11], we proposed a conceptual model to reflect the dynamics of individual and organizational factors in achieving the behaviour outcome (Fig. 1). These variables are interrelated in a theoretically meaningful way, and have reciprocal effects on each other in predicting individual PPE use behaviour.

The intervention design will correspond to the conceptual model, addressing the barriers related to the influencing factors and PPE use behaviour. Traditionally, behavioural interventions have often been delivered in a passive and ‘top-down’ manner, such as health education by providing lectures, posters and leaflets. However, a previous review about effectiveness of occupational safety and health interventions has shown that general health education and training may not suffice to lead to occupational health behavioural change, especially for workers in SMEs [23]. The effectiveness of education programmes is compromised by the difficulties education providers face in reaching migrant workers in SMEs as a result of the limited access to workplaces, lack of trust, and cultural and/or literacy barriers. Over the last decade, mobile phones have widely been embraced as an integral part of our daily lives. Consequently, mobile Health (mHealth) interventions were applied to help to improve physical and mental health, especially for people who have barriers or limited access to health services [24, 25]. To our knowledge, mHealth intervention has not been developed in the field of occupational health for migrant workers in SMEs. Whether it works for occupational health behaviour change for migrant workers is one of questions we are going to answer in this trail.

In addition, a more bottom-up approach such as volunteers and peer support can empower individuals and maximize their potential to achieve behaviour change. Peer education was found to be effective at reducing HIV-related risk behaviours [26]. Peer supports are particularly important for migrants who tend to be less integrated with the local communities [27, 28]. Enhancing the support and education between workmates may help improve their social integration, develop positive social norms and promote healthy behaviour.

In this study, we aim to compare the effectiveness of a top-down intervention (which combines general health education and mHealth intervention provided by the research team) and a more comprehensive intervention (which includes both top-down intervention and peer education), on improving the use of PPE among migrant workers in the SMEs in China. Specifically, we will: