**1. Introduction**

More than one-third of current U.S. workers suffer from at least one chronic disease, including heart disease, cancer, diabetes, stroke, and musculoskeletal disorders [1,2]. Working adults with chronic disease are more likely to have a reduced working capacity and greater difficulty staying at work than their healthy peers [3,4]. These chronic health conditions have an enormous impact in the lives of workers, but they also place a burden on their employers [3,5]. Healthy behaviors can reduce the effects of chronic conditions for better work (fewer missed days, increased productivity) and health (less musculoskeletal pain, improved mental health) outcomes [5–10].

The workplace is an ideal place for supporting healthy behaviors, since workers spend a large portion of their day in the work environment and coworkers and supervisors can provide substantial support. Traditionally, worksite health promotion programs have been separate from other occupational health and safety efforts, and usually target only the individual, ignoring work organization and work environment factors that affect worker behavior. The National Institute for Occupational Safety and Health (NIOSH's) Total Worker Health® (TWH) approach highlights the need for "policies, programs, and practices that integrate protection from work-related safety and health hazards with promotion of injury and illness prevention efforts to advance worker well-being" [11]. The TWH approach recognizes that work is a social determinant of health, and that workplace factors

such as work hours, relationships with coworkers and supervisors, and access to health and wellness programs have important effects on worker health and well-being. Further, TWH principles recognize the Hierarchy of Controls framework to illustrate that system-level interventions are more effective than individual-level interventions [12].

Regardless of the level of intervention, the most effective interventions are those that take into consideration the unique characteristics and perspectives of the end users [13,14]. Participatory methods such as Participatory Action Research and Participatory Ergonomics promote the inclusion of end users in the intervention development process [14–20]. These end users may be line-level workers who directly benefit from the intervention, managers or others who implement and monitor interventions, or others who are impacted by the interventions in some way. Including these users in the process allows their perspectives to be considered in identifying both workplace health hazards and possible barriers to adopting or participating in the planned interventions. Participatory methods are increasingly being used in Total Worker Health research and practice [14,17,21–28]. The most thoroughly studied participatory program in the TWH literature to date is the Healthy Workplace Participatory Program (HWPP) developed by the Center for the Promotion of Health in the New England Workplace (CPH-NEW). The HWPP is a worker-management participatory program designed to develop solutions for workplace problems that involve front-line workers. The freely available online program includes step-by-step guidance for assembling the participants, identifying problems, and developing and implementing solutions. The developers note the importance of organizational readiness and leadership support, and have recently developed a checklist to measure organizational readiness as well as a Process Evaluation Rating Sheet (PERS) and Management Dashboard [18,29]. This promising and relatively new program has been used in various work settings including corrections facilities, real estate, non-profit healthcare and social assistance agencies, and state government executive offices [28,30]. Publications to date provide little practical advice for implementing the HWPP program (e.g., characteristics most important for success, total time commitment, expectations of the design team, facilitator role). Further, the TWH literature as a whole discusses the utility of participatory approaches, but offers little guidance on how to comprehensively evaluate both implementation and efficacy of these programs while simultaneously considering the contexts in which they are delivered [12,13,31,32].

We sought to evaluate the feasibility of conducting a participatory health promotion program in a retail grocery store setting. We partnered with a regional grocery store chain who expressed interest in supporting their workers' health. Using the HWPP as a facilitation guide, we formed a team of grocery store workers and evaluated their ability to create meaningful and relevant workplace health activities that promote and support healthy behaviors in their workforce. The purpose of this paper is twofold: (1) to inform others considering a participatory intervention by describing the implementation of this HWPP program, and (2) to describe a framework for evaluating complex TWH interventions, such as the HWPP.
