The Evidence Base for Occupational Health Interventions

Defining Occupational Health Research

Occupational Health (OH) is an area that is constantly evolving and a clear definition for Occupational Healthcare research has not yet been established. Traditionally, OH has been focused on healthcare assessment, as well as the prevention and rehabilitation of certain conditions that relate to the work environment. Early research, therefore, explored issues such as hazards, trends and work related ill-health.

More recently, the scope of OH has evolved to consider the impact of health on work, return to work strategies, as well as how specific health conditions can be managed in the workplace. Around 60% of the population worldwide are estimated to spend approximately 60% of their waking hours at work, so it is possible to influence the health behaviours of a large number of individuals through work-based interventions.

These evolving research areas provide more information about trends of disease, risk factors and the outcomes of work interventions in relation to prevention of disease, early rehabilitation and return to work. By widening the scope of OH research, we are enhancing our understanding of how we can improve functional capabilities of workers and develop cost effective interventions.

History of Occupational Health Research

During the early 20th century, certain government agencies began to monitor and record trends in public health and disease. However, it was not until the end of the 20th century that countries, such as the US, United Kingdom, Italy and Japan started to develop OH research agendas. Priorities for each country were determined based on cost-benefit studies, workplace injuries, occupational carcinogenesis, psychosocial hazards and changing workforces and work patterns.

Priorities vary between countries based on economic and sociocultural background, as well as safety regulations, and work demographics. As funding is scarce for OH research, it is important that researchers understand their own national priorities in order to target funding and ensure that research is beneficial to the community.

Historically, OH research has focused on reducing the impact of traditional occupational diseases. However, due to technological advances, changes in workplaces/workforce and working population demographics, the discipline of OH has evolved. There is now a much greater focus on promoting health and wellbeing, as well as improving worker retention and the functioning of workers.

Recent OH research is now also considering mental health, work related musculoskeletal disorders, chronic conditions, and the management of long-term conditions in the workplace. It has started to explore in more detail OH safety services and the management structures in a workplace. These shifts in focus have created new challenges for OH research as it has to take into consideration these additional factors, but still relate to national priorities.

Limitations of Occupational Health Research

The actual evidence base for OH is relatively poor. There is a lack of work-focused healthcare. This means that physiotherapists who do not work in OH may not be taking into sufficient account work participation and work related factors during subjective interviews and when planning interventions. In addition to this, most of the conclusions about OH interventions have come from studies with bias or other methodological flaws. This is problematic as physiotherapists are required to be evidence based in order to demonstrate the merit of an intervention to policy makers and insurers/funders.

Recent Occupational Health Research

This section will explore some of the recent OH research. The articles chosen focus on musculoskeletal issues in the workplace as this is a high priority area for most governments - in 2017, 28.2 million days were lost due to musculoskeletal conditions in the United Kingdom and 154 million days were lost in in 2016 in Germany - it is also particularly relevant to physiotherapy.

Evidence of Workplace Interventions - A Systematic Review of Systematic Reviews

This review by Pieper, Schroer and Eilerts from 2019 summarised current evidence of health promotion interventions in the workplace. It reviewed musculoskeletal disorders, psychological and behavioural disorders and looked at interventions for older workers, as well as economic evaluations. While they were able to provide some consistency in certain workplace interventions, such as exercises, training/education programmes, ergonomic desk/chairs to reduce pain for people with musculoskeletal disorders, the evidence is at best moderate. As a result, they note that there is not enough evidence to recommend specific interventions or programmes.

Effectiveness of Workplace Interventions in Return-to-Work for Musculoskeletal, Pain-Related and Mental Health Conditions: An Update of the Evidence and Messages for Practitioners

This systematic review by Cullen et al from 2018 updated an earlier study done in 2005. They found strong evidence that Move to Remain at Work Interventions can reduce lost time associated with musculoskeletal injuries and pain related conditions and can improve work function.

A systematic review on workplace interventions to manage chronic musculoskeletal conditions

This systematic review by Skamagki et al (2018) explored whether there are effective workplace interventions to help address chronic musculoskeletal disorders. However while there was some consistency suggesting that high-intensity strength training and/or the use of integrative programmes in a workplace can reduce pain and symptoms, the number of studies are limited. They, therefore, suggest that the use of a multicomponent workplace intervention is beneficial in the management of chronic musculoskeletal conditions in the workplace.

Systematic review: height-adjustable workstations to reduce sedentary behaviour in office-based workers.

This Cochrane review by Tew et al (2018) looked at interventions that reduced sitting at work. They found low quality evidence to support the use of sit to stand desks to reduce sitting in the short/medium term. There was no evidence about their impact on sitting over longer follow up periods. Moreover, there was low to very low quality evidence for most interventions on this area (physical workplace changes, workplace policy changes, information ad counselling and multi-component interventions).

Early workplace dialogue in physiotherapy practice improved work ability at 1-year follow-up - WorkUp, a randomised controlled trial in primary care. 

This study by Sennehed et al (2018) found that primary care physiotherapists who establish an early dialogue with an employer in addition to physiotherapy services improved workability when compared to physiotherapy alone.

Workplace-based rehabilitation of upper limb conditions: A systematic review.

This review by Hoosain et al (2018) also found high or moderate level evidence to support the use of workplace exercise programmes in the management of upper limb conditions. However, they found that other work-based interventions (ergonomic control, work station adjustments, etc) require further research.

Effectiveness of workplace interventions in the prevention of upper extremity musculoskeletal disorders and symptoms: an update of the evidence.

Similarly, this systematic review by Van Eerd et al (2015) found strong evidence to support the use of resistance training to manage upper extremity musculoskeletal disorders and symptoms, but the evidence for other interventions was less consistent. There was only moderate evidence to support the use of stretching programmes, mouse use feedback and forearm supports. They also found that there was moderate evidence for no benefit for EMG biofeedback, job stress management training and office workstation adjustment.

Effects of job rotation on musculoskeletal complaints and related work exposures: a systematic literature review.

This systematic review by Leider et al (2015) examined the effects of job rotation on musculoskeletal complaints. However, the evidence was weak and it was not possible to draw strong conclusions from the studies reviewed.

The effectiveness of a chair intervention in the workplace to reduce musculoskeletal symptoms: a systematic review. 

This systematic review by Niekerk et al. (2012) found that there was moderate evidence from five studies to support the use of ergonomic interventions such as adjustable sit to stand desks to reduce neck or back pain. However, the authors noted that they were unable to make strong recommendations and that further clinical trials need to be undertaken.