Reducing Pain-Related Sickness Absence Through Workplace Health Literacy: A Hybrid II Study

The goal of this hybrid II randomized stepped wedge trial is to investigate if an organizational workplace health literacy intervention reduces pain-related sickness absence and pain intensity, and improves occupational health literacy - and to understand how and for whom the intervention can be successfully implemented and sustained in real-world workplaces within production sites.

1. Effectiveness: To evaluate the effectiveness of the intervention on the primary outcome of pain-related sickness absence (days lost) and secondary outcomes of pain intensity and occupational health literacy.

Hypothesis: Receiving the intervention will lead to fewer pain-related sickness absence days, lower pain intensity scores, and higher occupational health literacy compared to receiving usual care during the control condition/phase. 2. Implementation - Barriers, Strategies and Mechanisms: To identify implementation barriers and targeted implementation strategies and to specify the underlying mechanisms of action supporting effective implementation and sustainability.

Objective: To enhance local adoption, implementation and sustainability of the intervention. 3. Implementation - Process: To provide an assessment of the implementation process, focusing on adoption, reach, fidelity, and sustainability across participating workplaces, and to identify contextual and processual factors that promote or hinder successful implementation.

Objective: Produce actionable implementation guidance and an evidence-informed strategy for broader roll-out and long-term maintenance.

A stepped-wedge design is a type of a crossover study in which clusters cross over from the control arm to the intervention arm at different randomized time points. The clusters will be formed based on working teams (consisting of approximately 15 workers), randomly assigned to a step (of implementation of the intervention) four months apart.

During the control phase/step, the participants receive standard care. In the workplace context, this implies that the control group can address work environment and health and safety issues through discussions within their health and safety organization. In Denmark, for workplaces with 10-34 employees, collaboration on health and safety is mandated to be organized within a health and safety organization, comprising one or more supervisors and one or more elected health and safety representatives, with the employer or a representative of the employer serving as chairman. This health and safety organization is tasked with both day-to-day and overarching responsibilities related to health and safety. Furthermore, workplaces or teams within the control group retain the option to seek assistance from trained work environment professionals external to their workplace if they choose to do so.

The intervention consists of 4 elements;

1. A training day for the local workplace champion. 2. Needs and resource assessment at the workplace 3. Digital education in pain, communication and solutions for employees and managers 4. Structured 1:1 dialogues between workers and their supervisor.

Method This project builds and extends upon a successful pilot of an organizational workplace health literacy (OWHL) intervention. Guided by the revised Medical Research Council (MRC) framework, the project aims to further develop, refine, and evaluate the effectiveness and implementation of the intervention and its core components to support the creation of a scalable workplace intervention suitable for implementation in production sites. The project will address the pilot study's limitations by

1. randomizing to reduce bias, 2. focus on an initial workplace needs assessment integrating a newly developed self-assessment workplace tool 3. Integrating a cost-effective digital Educational Program, and 4. tailoring implementation strategies to the particular target group and context/setting to ensure optimal uptake.

Addressing these limitations of the pilot study is essential to strengthen the validity of the findings and enhance the intervention's practical applicability.

Study setting and population The study population encompasses the 280.000 workers employed within production in Denmark, whereof 42 % are 50 years old, or older. This large working group is characterized by high physical and psychosocial work demands, with known potential challenges within safety communication between management and employees working the machines. Additionally, production workers experience around 10 days of sickness absence per year, report that they are overworked, and have elevated levels of pain, with a weekly pain prevalence of 43%. Consequently, this group is predisposed to an elevated risk of long-term sickness absence, and, in the most severe circumstances, premature withdrawal from the labor market.

Randomization and blinding To avoid contamination between workers, cluster randomization will performed, with each working team constituting a cluster. The randomization will be balanced on the size of the working teams. A blinded independent data manager will perform a computer-generated randomization. Blinding of participants is not possible, owing to the nature of the trial. Data collection will be performed using questionnares delivered through text messages, and data managers and research personnel collecting/handling data will be blinded to group allocation if deemed practically feasible.

• Pain intensity [Time frame: From baseline, before entering the stepped wedge control period, to the end of treatment at 16 weeks]