Rebecca M. Brossoit, Ph.D., Oregon Health & Science University; Leslie B. Hammer, Ph.D., Oregon Health & Science University, Portland State University; Todd E. Bodner, Ph.D., Portland State University; Tori L. Crain, Ph.D., Portland State University; Krista J. Brockwood, Ph.D., Oregon Health & Science University
The purpose of this work is to evaluate effects of The Military Employee Sleep and Health study’s Family and Sleep Supportive Training (FaSST) intervention on workplace safety outcomes. We hypothesized that service members in the treatment group would report greater safety compliance, safety participation, and safety motivation, and would be less likely to experience a work-related accident or injury 9-months following the intervention compared to those in the control group. Additionally, we hypothesized that the effects of the intervention on 9-month safety outcomes would be mediated by greater sleep duration and quality at 4-months, as well as increased perceptions of supervisors? sleep leadership behaviors and sleep education at 4-months.
Total Worker Health (TWH) is an approach that extends traditional occupational health and safety frameworks to address worker health protection and promotion, with an emphasis on well-being (Schill & Chosewood, 2013; Anger et al., 2014). Although TWH interventions have demonstrated promising findings for worker health, safety, and well-being (Anger et al., 2014), it is uncommon for TWH interventions to employ rigorous study designs or target sleep. Given that the FaSST intervention targeted support for family and sleep, and past research has demonstrated links between sleep and workplace safety (e.g., Barnes & Wagner, 2009; Brossoit et al., 2019; Kao et al., 2016; Uehli et al., 2014; Watson et al., 2015), we expected to find intervention effects on workplace safety through greater sleep and support for sleep.
The FaSST randomized controlled trial intervention involved training supervisors on how to support their service members’ sleep and life outside of work. Additionally, participants tracked their sleep for three weeks with actigraph watches and received personalized sleep feedback reports to learn about their sleep patterns and set sleep-specific goals. Survey data were collected at baseline and 4- and 9-months following the intervention. Participants were full-time service members in the Army and Air National Guard.
Sleep duration was assessed using the Pittsburg Sleep Quality Index (Buysse et al., 1989), and scales from the Patient-Reported Outcome Measurement Information System (Yu et al., 2012) were used to measure insomnia symptoms (trouble sleeping), dissatisfaction with sleep (perception of sleep quality), and sleep-related impairment (feeling tired and having mood or behavioral problems due to poor sleep). Gunia and colleagues’ (2015) measure of sleep leadership was used (e.g., encouragement of subordinates to get enough sleep) and sleep education was assessed with two items that were created for the MESH study (e.g., supervisor sharing knowledge about sleep). Safety compliance (following required workplace safety protocols), safety participation (voluntarily promoting workplace safety), and safety motivation (personal belief in the importance of workplace safety; Neal & Griffin, 2006), as well as serious workplace accidents and injuries that required professional healthcare, resulted in loss of consciousness, or restricted normal activities were assessed. See Table 1.
All data have been collected and all analyses have been completed. Analyses were conducted within an intent-to-treat framework (McCoy, 2017) and using an analysis of covariance approach in which baseline values of the mediating and dependent variables were modeled as controls (Bodner & Bliese, 2018). To account for the nesting of service members within workgroups, two-level regression analyses were used to test intervention effects and complex regression analyses were used to test mediated effects. For mediated effects, bootstrapping with 5,000 bias-corrected bootstrapped samples was used (Fritz & MacKinnon, 2007) and statistical significance was determined as asymmetrical 95% confidence intervals that did not contain zero.
There were no intervention effects on the 9-month workplace safety outcomes. Instead, there were indirect effects of the intervention on greater safety participation and safety motivation, and reduced accidents and injuries at 9-months, through reduced sleep-related impairment and reduced dissatisfaction with sleep at 4-months. Additionally, there was an indirect effect of the intervention on safety compliance and safety participation at 9-months through greater sleep leadership from one’s supervisor at 4-months. Finally, there was an indirect effect of the intervention on safety participation at 9-months through greater supervisor sleep education at 4-months. See Table 2.
Service members in the treatment group reported improved sleep quality and greater perceptions of sleep-specific support from their supervisors, which in turn predicted greater workplace safety behaviors and reduced workplace accidents and injuries. A limitation of this study is that minor workplace injuries (e.g., bruises, muscle strains) and near misses were not examined. The development, implementation, and evaluation of a randomized controlled trial TWH intervention using nested and longitudinal data are methodological strengths of this study.
The FaSST intervention indirectly improved workplace safety, providing support for the benefits of integrated intervention approaches, like TWH, and for the critical roles of sleep and supervisor support for workplace safety. Future research should examine other health, safety, and well-being outcomes of the FaSST intervention and translate the intervention for non-military populations.