Background
Sustained health takes a prominent place in daily life and work. (Temporary) inability to work optimally due to health problems causes high productivity loss, and poses a great burden on individuals and society [
1,
2]. This burden is expected to increase, because of an aging workforce [
3,
4]. Common to a production environment are injuries and diseases related to musculoskeletal disorders (MSDs). Prevalence of musculoskeletal disorders among workers in the meat processing industry is especially high, with percentages of over 90% [
5‐
7]. MSDs may originate from personal factors such as age, genetics, and Body Mass Index [
8] or various contextual factors, such as job demands, job design, seasonality and environmental influences [
9] or a combination of both.
The growing proportion of older people in the labour force stresses the need for new policies and programs to assure sustainable employability and to decrease the financial burden. Sustainable employability is defined as employees having the opportunity to perform work with preservation of health and wellbeing during their working life, now and in the future [
10]. It is considered a multifactorial concept that can be assessed by multiple outcome measures. Commonly used proxies for sustained employment are work ability, productivity and absenteeism [
11,
12]. For instance, work ability (measured with the Work Ability Index; [
13]) was observed to be a strong predictor of sustained employment which means that employees with lower reported work ability are more likely to develop health complaints and retire early [
4,
14].
To prevent long term sickness and work disability, risk inventory and evaluations (RI&E) have been introduced at the workplace. One of the outcomes of a RI&E is a plan to minimize potential risks for both employee and employer. In 2009 and 2010, the Dutch Labour Inspectorate performed nationwide inquiries at multiple meat processing companies. The main risk factors identified for sustained employability were related to job demands and job design (machine handling, knife handling, repetitive movements, static postures, work pressure), and contextual factors (work on platforms, biologic agents, noise, safety measures) [
15,
16]. Personal factors, such as age, ethnicity and employment status, were not examined, but may well form a risk factor [
8].
To promote sustained employability, workers’ health surveillances (WHS) have been developed with the aim of promoting sustained employability and health, and of reducing medical costs [
17]. A WHS program is developed to provide employees insight into their work ability and health status. This may offer them the opportunity to increase their probability of sustained employability and reduce potential health risks. Recently, some job-specific WHSs and job-specific interventions have been reviewed [
18]. In the WHSs workers were screened on several health factors. In the interventions physical and psychological training were deployed to improve job performance. The effects of physical interventions were diverse: healthy lifestyle promotion, physical readiness training and resistance and endurance training were effective on job performance; an exercise intervention program was partly effective; respiratory muscle training was ineffective. One psychological intervention (trauma resilience training) proved to be effective on police performance. Kreis and Bodeker [
19] observed positive effects of workplace health promotion, which is practically similar to a WHS, on several health risks (smoking, weight control, and physical fitness). They also observed positive cost-benefit ratios of 1:2.5 and higher for workplace health promotion programs and their effect on absenteeism. Occupational health examinations, i.e. the screening part of a WHS, including a functional capacity evaluation (FCE) have also been reviewed [
20,
21]. Conflicting evidence was observed for the effectiveness of occupational health examinations including FCE on the prevalence of musculoskeletal injuries [
20]. These inconclusive results underscore the need for investigation and evaluation of an integral WHS program. Furthermore, an integral WHS program, including physical, mental and integrated interventions, and its effects on sustained employability has not been studied before.
The POSE program (Promotion Of Sustained Employability) was developed using elements from occupational and rehabilitation medicine. Elements from occupational medicine are e.g. WHSs, and interventions aimed at a healthy lifestyle. Elements from rehabilitation medicine are e.g. FCE, and interventions aimed at improved physical capacity. The POSE program offers employees a custom-made risk profile and, if necessary, an intervention plan using an integral approach [
10]. The goal is to reduce sickness absence and, hence, reduce inflow of workers into the ‘Dutch law for Work and Income according to work ability’ (WIA), to prevent income reduction, and to increase sustained employability. The FLESH evaluation study (Functional Labour Evaluation for Sustained Health and employment) was developed to provide insight into the effectiveness of this integrated approach on several outcome measures over time.
Objective and research questions
The purpose of the FLESH study is to evaluate the effectiveness and cost-benefit of the POSE program on work ability, productivity, and sickness absence among employees in the meat processing industry, compared to care as usual (CAU). The secondary aims are to improve perceived psychosocial and physical workload, health status, and vitality. Along with these evaluations a process evaluation will be conducted among employees and other stakeholders. The objective of this paper is to present the study protocol used in the FLESH study in which the following research questions will be addressed:
1)
Does the POSE program improve the primary outcome measures work ability, absenteeism and productivity compared to CAU?
2)
Does the POSE program improve the secondary outcome measures psychosocial workload, physical workload, subjective health status and vitality compared to CAU?
3)
Is the effectiveness of the POSE program influenced by age, program adherence, risk category, or motivation of management?
4)
To what extent do the applied methods appeal to the needs of the involved stakeholders (intervention acceptability)?
5)
Is the implementation of the POSE program cost beneficial from the employers’ perspective?
Discussion
This paper presents the design of a stepped wedge trial to evaluate the effectiveness of a comprehensive workers’ health surveillance program in a meat production environment. The POSE program aims to balance the functional capacities of employees with work demands. Detecting and restoring imbalances between capacities and demands in an early stage may contribute to sustained employability.
The current state of WHS programs and the use of FCEs in employment examinations have recently been reviewed [
20,
21]. The authors observed no evidence for an association between the length of FCEs and injury relapse. They also observed that general health examinations did not lead to decreased sickness absence, but did lead to more rejected job applications. Furthermore, they observed that job-specific pre-employment examinations lead to reduced occupational disease, injury or sickness absence. The effectiveness of pre-employment examinations, including FCE, on musculoskeletal injuries could not be demonstrated. On the other hand, several individual studies have demonstrated the predictive value of FCE on sustainable return to work [
53], risk for future work disability [
54] and claim closure / benefit suspension [
55,
56]. Better FCE performance was associated with better outcomes, i.e. earlier return to work, lower risk for future work disability and earlier claim closure. In the above mentioned studies WHS and FCE results were used in association with work outcomes, not as a screener to deploy tailor-made interventions. No studies were identified reporting on WHS, FCE and integrated interventions, which underpins the need for this study.
Strengths
To our knowledge this is the first study that evaluates a WHS consisting of multiple assessments, i.e. a questionnaire, biometric assessments, and FCE, and that also deploys tailor-made interventions.
The design of our study has some benefits over a parallel arm randomised controlled trial. The design allows to perform a within group and between group analysis, i.e. each plant serves as its own control, but also serves as control for the other plants. This limits the risk of confounding and increases statistical power.
A strength of this study is the expected high participation rate of the POSE program. During a pilot study at two locations (not included in this study), the participation rate was 80-90%. We expect the same participation rates within our study. We strive to reach this participation throughout the entire study period. During the follow-up measurements we expect this rate to decrease over time. A careful distribution process and clear communication about the follow-up questionnaires might mitigate this decrease.
When the POSE program proves to be effective within the company, we expect that the results of this trial can be used by other companies in the sector, which employ approximately 20,000 people in The Netherlands. Especially, since multiple plants are included in this study, this provides more generalisable results for all production workers. This WHS program was job-specific, so perhaps results cannot be generalised directly to other sectors. However, it is reasonable to presume that a custom-made WHS program can be adapted to other related sectors with similar results.
Limitations / weaknesses / risk of bias
We have not included translations of our questionnaire for foreign employees, whose Dutch language skills may be insufficient to complete the questionnaire. In the Dutch meat processing industry, about 25% of the employees is born outside The Netherlands [
15]. We strive to assist those employees in filling out the questionnaires, but this will probably not be feasible in some cases. This issue may therefore limit the generalisability of our results. Another issue that might have impact on the generalisability of the findings is the fact that temporary production workers could not be included in the study, because of practical reasons. These workers are common in the meat processing industry (approx. 30%) and many are foreign [
15,
16]. Thus, a substantial part of all workers in this study will expectedly not participate, which limits generalisation towards these groups.
The company has already been working on absenteeism reduction for a few years before implementing the POSE program. In these years, sickness absence has dropped from 7.0% to 4.5%. It is unknown whether this may lead to floor effects. Possible effects of the POSE program might therefore go unnoticed. Perhaps it is not realistic to expect absenteeism rates to drop even further, due to the type of work.
Plants where the POSE program has not yet been implemented could already perform health related activities prior to implementation of the POSE program. Such activities might influence the results of the POSE program and therefore influence possible effects of the POSE program. We emphasized that the company should not start health-related activities prior to POSE program implementation, other than care as usual activities.
Scientific relevance
Within our study an integrated approach is deployed. The study will yield valuable information on the effectiveness of this approach on work related outcomes. Combining the results of the process evaluation and the intervention effects will hopefully provide insight into the effectiveness of separate aspects, and perhaps underlying reasons for the effectiveness.
Practical application
The results of this study will provide information on the effectiveness of the POSE program on sustained employment. When the program proves to be effective, employees will benefit from this by an improved health and perhaps a healthier working environment. Employers might benefit from healthier employees, and in the case the intervention proves to be cost-beneficial, reduced costs and higher productivity. Furthermore it will expose key elements for a successful implementation and execution of the POSE program and may serve as an example to other companies inside and outside the industry.
Acknowledgements
The authors wish to acknowledge all participating parties for their contributions to the FLESH study. We thank VION Food Group B.V. for the opportunity to perform the study within their company. We thank University Centre ProMotion Groningen (UCPG) for their role in the design of the study.
Business Health Support (BHS) is the occupational health service and responsible for the POSE program and has an intermediary role towards VION Food Group B.V. Immens Advies executes the POSE program at the plants and is responsible for data collection and reporting. We thank them both for their contributions to the study.
This study has been granted by ZonMw, a Dutch funding organization, under project number 208030005.
Competing interests
All authors declared that they have no competing interest.
Authors’ contributions
RS, MR and SB developed the initial study protocol and acquired funding for the FLESH study. They also provided valuable input to this design paper, which was drafted by BvH, MdB, and RS. All authors commented on the draft versions. All authors read and approved the final manuscript.