Productivity as an efficacy measure in rest-shade-hydration interventions: the need for a more complete dissemination and implementation science approach

Environmental heat exposure has been an occupational safety and health (OSH) concern for decades (Lind 1960). As temperatures have increased worldwide, more attention has been paid to the impact environmental heat exposure will have on workers (Schulte and Chun 2009; Schulte et al. 2016; 2023). Links between increased heat exposure and heat-related illness (Crowe et al. 2015) and injury (Dally et al. 2020) have been documented in high-risk industries and occupations in agriculture, construction, mining, and other sectors globally. In addition, evidence suggests a combination of nephrotoxins and increased temperatures have led to the emergence of Mesoamerican Nephropathy, a form of chronic kidney disease prevalent in agricultural communities (Johnson et al. 2019). These work-related injuries and illnesses have led to the need to further develop and evaluate workplace safety protections for workers exposed to environmental heat (Morrissey et al. 2021), as discussed by Hansson et al. (2024) in the February issue (Hansson et al. 2024).

The paper by Hansson et al. advances the case for considering the effect of heat on worker productivity, in addition to more conventional health and safety outcomes. It also raises three important issues for researchers to consider as we design the next generation of studies. First is the need to apply a dissemination and implementation science framework to the design and evaluation of interventions. The second is a need for these studies to be replicated and evaluated in additional cohorts and industries. Finally, there is a need to further understand the organizational factors, including productivity incentives and how we measure productivity, which may influence the success of the intervention.

The emerging field of dissemination and implementation science emphasizes the need to go beyond studying the efficacy of interventions by evaluating how and why interventions succeed or fail (National Institutes of Health 2021). In 2022, Guerin et al. (2022) highlighted 8 key implementation outcomes to consider in design and evaluation of OSH interventions. These include: (i) the OSH intervention is agreeable or satisfactory for workers and employers (acceptability); (ii) the intention of the employer and workers to use the OSH intervention (adoption); (iii) the “fit” of the OSH intervention to the needs of the worksite (appropriateness); (iv) the attributable expense of the OSH intervention (costs); (v) how successfully the intervention can be used within the worksite (feasibility); (vi) degree of agreement between the OSH intervention components as implemented versus how they were designed (fidelity); (vii) the integration of the OSH intervention within the worksite (penetration); and (viii) the extent to which the OSH intervention is maintained within the worksite (sustainability) (Guerin et al. 2022).

In this issue, Hansson et al. evaluated the efficacy of a Rest-Shade-Hydration (RSH) intervention along-side changes in sugarcane-cutting practices on the productivity of sugarcane harvesters in Nicaragua. The authors conclude that the intervention had no negative impact on the productivity of workers. These findings are consistent with the findings of their team’s pilot study in El Salvador in which Bodin et al. (2016) (using a similar intervention that included RSH as well as the introduction of an ergonomically improved machete), asserted that “with proper attention to work practices, production can be maintained with less impact on worker health” (Bodin et al. 2016). The authors use these results to support the conclusion that decreasing the total time allotted to work by increasing rest breaks resulted in no reduction in worker productivity.

While efficacy outcomes are an important cornerstone of intervention study assessment, Hansson et al. do not address other implementation outcomes that may influence the intervention effectiveness. These include barriers to adoption and fidelity. Glaser et al. (2022) suggest that the adoption of the 5-year RSH intervention that Hansson et al. evaluates for efficacy may be insufficient, observing that “across the jobs and settings, only about one-quarter of the prevention program demonstrated ‘sufficient’ implementation of the full program” (Glaser et al. 2022). While the authors do not evaluate why factors may undermine intervention delivery, it suggests the possibility that the effect of the RSH intervention on productivity might be the result of low adoption rather than an effect of the intervention itself. Without attention to the adoption of the intervention, one cannot assess if the null effect on productivity was due to the intervention itself or arose from limited adoption of increased rest breaks. This finding highlights the need for researchers to examine process measures alongside measures of efficacy and effectiveness (Guerin et al. 2022).

As a next step, replication of productivity studies will need to move beyond a single research group, company, and industry to define what impact RSH interventions may have across industries and workforces that share similar exposures to heat. To aid in replication, authors should take care to fully disclose the contribution of all components of their multi-pronged interventions. In the Hanson et al. paper, for example, it is difficult to determine how much of the “increased productivity” attributed to RSH may be due to “improved work practices.” Ultimately, successful dissemination will depend on researchers’ and industries’ ability to replicate the intervention and evaluate if it is acceptable, appropriate, and feasible for new settings. To meet these goals, it is likely that intervention components will need to be tailored, highlighting further the need for thorough descriptions of all intervention components when evaluating their effectiveness.

The final important point raised by this paper is how organizational factors may influence intervention success, including how employers incentivize productivity and how organizations measure it. OSH interventions that include reduction in workable hours may have economic impacts on both the company and the worker. This is especially true for piece-rate workers and those striving to work in poor economic conditions (Schulte et al. 2016). For these workers, participation in an RSH intervention may increase both psychosocial and financial stress. Self-efficacy is based on a worker’s perception of their capacity to deal with the stressors of their work, in this case maintaining productivity quotas (Priuli et al. 2014). It is posited that increasing productivity demands through reducing workable hours reduces self-efficacy and increases stress (Priuli et al. 2014). In the context of Hansson et al., it is important to consider possible financial hardship of reduced work hours as well as the associated psychosocial and other health impacts of participating in such an intervention, especially if organizational pay structures and incentives are unchanged. As a final note, while productivity metrics, such as the daily number of seed sugarcane bundles per worker, are quantifiable and immediate, other metrics such as employee absenteeism (Jinnett et al. 2017) and retention (Dally et al. 2018) may prove equally or more important to employers faced with labor shortages.

As global temperatures increase, there is a need to continue to develop efficacious strategies to protect workers. As we do so, we must critically evaluate the interventions for not only well-defined efficacy outcomes but contextualize those findings with implementation outcomes. We must also more critically consider potential consequences of well-intended interventions, produced by mechanisms such as revised incentive structures, bearing in mind the indicators of decent work (International Labour Organization, 2012).

Funding

No funding was provided for this project.

Conflict of interest statement

The authors declare that the University of Colorado and Pantaleon, a sugarcane company headquartered in Guatemala, have a Memorandum of Understanding. The University of Colorado employed appropriate research methods in keeping with academic freedom, based conclusions on critical analysis of the evidence, and reported findings fully and objectively. The terms of this arrangement were reviewed and approved by the University of Colorado in accordance with its conflict of interest policies. The contents of this Article, including any opinions and/or conclusions expressed, are solely those of the authors.

Data Availability

No data were used in this manuscript.

References