Introduction
In many developed nations, construction workers have higher rates of suicide than other occupational groups [There are some notable contextual factors that are posited to underpin the elevated rates of suicide among construction workers. In particular, adverse psychosocial working conditions [Workplaces are legislatively bound to provide safe work environments and reduce physical and psychosocial hazards. Furthermore, many workplaces have structures and resources that can support workplace suicide intervention programs (e.g. OH&S professionals, human resource personnel, union delegates). Thus, the construction workplace represents an appropriate setting for suicide prevention interventions. On this basis, Mates in Construction (MATES) was established in 2008. A charity, MATES leads an industry-based, bi-partisan, multimodal workplace-focused suicide prevention program that is delivered at construction sites and company offices.A central component of the MATES program is a 45-min face-to-face group awareness training, General Awareness Training (GAT). For a site to be designated as ‘MATES inducted’, all workers on that worksite must participate in GAT, with an 80% training level maintained even with staff turnover. Other components of MATES build on the initial awareness raising session, and have been described elsewhere [Digital technologies are omnipresent worldwide: this is particularly characterised by almost pervasive use of smartphone technology and widespread internet connectivity. There is growing interest in the use of smartphone technology, through the use of applications (apps), to deliver or supplement interventions for different health needs [Several uncontrolled evaluations have suggested that MATES face-to-face training has face validity and is an appropriate intervention for workers in the construction industry [There is a need for better evidence of the effectiveness of such applications in supporting mental health. Few smartphone applications have been rigorously evaluated with comparison to a control condition, resulting in concerns around the quality of available apps [greater improvement in suicide prevention literacy,increased help-seeking intentions for emotional problems,increased help-seeking intentions for suicidal thoughts.