Systematic review findings

The systematic reviews listed below are those conducted by research teams led by or including an Institute for Work & Health (IWH) researcher and conducted according to the methods developed by IWH's Systematic Review Program. Systematic reviews conducted by IWH researchers for Cochrane Back and Neck (CBN) are available from the CBN website.

Completed systematic reviews

Listed below are systematic reviews completed as part of IWH’s Systematic Review Program.

Prescription drugs that act on the central nervous system (CNS)—e.g. opioids, benzodiazepines, stimulants—are associated with various adverse effects, including cognitive and psychomotor impairments. Their non-medical use is considered a public health risk for serious harms. Use of medical cannabis has also seen tremendous growth in recent years, and the Canadian government has committed to legalization of non-medical cannabis in 2018. There is a need to balance the therapeutic benefits of these drugs and a worker’s personal autonomy against their potential workplace risks. Given current trends, this will remain a challenge for clinicians, employees, employers and workers’ compensation systems for the indefinite future. This systematic review will consider some of the most deleterious potential workplace outcomes of these agents: workplace injury and fatality.
Male and female differences in the area of work and health can manifest in two different ways. First, the incidence and prevalence of work exposures or work-related health outcomes can differ by gender/sex. For example, men are exposed to greater noise exposures at work than women; women have higher rates of upper body repetitive movement injuries than men. Second, the relationship between work exposures and outcomes can differ for men and women. For example, the relationship between low job control and hypertension is stronger for men than for women; the relationship between shift work and work injury is stronger for women than for men.

Because of these gender/sex differences, policy responses to research in these two areas will (or should) differ. Where the incidence or prevalence of work exposures or health outcomes differ for men and women, prevention approaches should focus on reducing gender/sex inequalities. However, where the relationship between work exposures and outcome differ, prevention approaches should focus on being gender- or sex-specific.

As policy-makers become increasingly interested in taking gender/sex differences into account in their primary prevention approaches, there is a need to summarize the existing research evidence to find where inequalities in exposures and health outcomes exist between men and women.
Upper extremity musculoskeletal disorders (MSDs) include painful conditions and injuries of the muscles, tendons, joints and nerves that affect the neck, shoulders, elbows, wrists and hands. In Canada, upper extremity MSDs and low-back pain are the leading causes of disabling work-related injuries. ​This systematic review updated a 2008 review of the role of occupational health and safety interventions in the prevention of upper extremity MSDs.
Small businesses have unique challenges with occupational health and safety (OHS). Overall, workers in a small business have a higher risk of workplace injury than workers in large firms, yet both workers and owners may not have a sense of this increased risk. Small businesses are more likely to face financial instability than larger firms. Together, these situations create a challenge in understanding and managing the risk of workplace accidents. This systematic review was conducted to provide an understanding of, and guidance on, how to implement OHS in small businesses, and to identify effective OHS programs
Injury/illness prevention and loss control programs help protect workers from injuries, meet regulatory requirements, reduce the negative effects of injuries and manage costs. These programs include the three Ps: work practices among employees, policies developed by employers, and programs required by legislation. The purpose of this systematic review was to identify studies that evaluated the effect of injury/illness prevention and loss control programs on reducing the frequency and/or severity of workplace injuries.
Depression in the workplace is widespread, and workplaces feel its financial pinch in the form of absenteeism and presenteeism. Yet workplace programs that specifically target depression remain uncommon. This may be because little information is available on the effectiveness of these programs when it comes to improving outcomes of importance to employers.

This systematic review set out to provide such information. Keeping the relevance and quality of studies in mind, it searched the research literature to look for successful interventions for managing depression in the workplace that were effective from an employer's point of view.
Occupational health and safety management systems (OHSMSs) have developed considerably over the last 20 years, yet little is known about their effectiveness. The systematic review aimed to answer these questions: What is the relative effectiveness of mandatory and voluntary OHSMSs on employee health and safety and on associated economic outcomes? What facilitators and barriers are there to the adoption and the effectiveness of OHSMSs? What is the evidence on the cost-effectiveness of OHSMSs?
There is evidence that the inappropriate design of workplaces and work processes contributes significantly to the development of common work-related musculoskeletal disorders (MSDs). By improving ergonomic aspects of work and workplaces, it should be possible to prevent or reduce these disorders and increase productivity. IWH conducted a systematic review to summarize the existing scientific literature on the effectiveness of workplace-based participatory ergonomics interventions in improving workers' health.
A systematic review of workplace-based return-to-work (RTW) interventions was carried out by the Institute and published in 2004. The review included studies published between January 1990 and December 2003. This project updated that original work using an enlarged scope of review to examine the process dimensions of workplace-based RTW and work disability management interventions/support. This project included and updated both the quantitative and qualitative literature. The updated review facilitates the integration of high-quality best practice research evidence into the development of return-to-work policies and programs.
What individual, job and workplace factors are associated with occupational disease among young people 12 to 24 years of age? This is an important question for three reasons. Since young workers are concentrated in certain industries and jobs, they may have different exposures to hazards than older workers. Since young workers are being exposed to hazards for the first time, the link between exposure and disease may be clearer. And, since young workers are still developing, they may be more vulnerable to work-related diseases. IWH undertook a systematic review to determine what factors are associated with occupational disease among young workers.
Health-care workers face a high risk of developing injuries to their muscles, tendons or other soft-tissues, including back pain. These injuries are also known as musculoskeletal disorders (MSDs). Activities such as lifting and handling patients are one of the main causes of MSDs in health-care workers. Many prevention initiatives – such as using mechanical patient lifts, physical exercise programs or education programs – have been used to try to prevent MSDs from occurring in health-care workers. However, little is known about the effectiveness of these programs. This systematic review summarized the existing scientific literature on the effectiveness of MSD prevention programs for health-care workers.
Before employers invest in workplace health and safety interventions, they want to know the financial implications of their investment. The goal of this review was to explore whether such interventions are worthwhile from an economic point of view.
To find an answer, the Institute for Work & Health conducted a systematic review of studies of workplace-based health and safety interventions that also included an economic evaluation. An economic evaluation is a study in which a researcher or decision-maker assesses the costs and consequences of a particular intervention and its relevant alternatives. This review sought to answer the following question: What is the credible evidence that incremental investment in health and safety is worth undertaking?
The use of occupational health and safety (OHS) audits has grown in recent years. Auditing is now seen as an effective method for ensuring compliance and improving the performance of prevention systems. IWH carried out a narrative literature review in order to determine what is known about the reliability and validity of these audit instruments. Besides reviewing literature in OHS, the team looked at findings from the process safety field as well.
In participatory ergonomics (PE), a team works together to identify risks and change tools, equipment and work processes to improve workplace conditions. PE interventions have been shown to reduce work-related injuries to muscles, tendons, ligaments and other soft tissues. What elements of a participatory ergonomic intervention can help ensure its success in workplaces? This systematic review set out to answer this important question.
Workers, employers and workers’ compensation boards have many questions about the impact of low-back pain (LBP) on return to work. The Institute for Work & Health (IWH) previously assessed the evidence on factors that predict duration of time away from work among workers who are at the beginning of a LBP-related episode. In 2005, IWH published a systematic review on prognostic factors for duration on sick leave due to acute low-back pain. This study expanded this systemic review by looking at the prognostic factors for duration on sick leave due to chronic low-back pain.
What factors affect how long it will take workers to return to work following an episode of acute low-back pain (LBP)? This systematic review from the Institute for Work & Health (IWH) aimed to find out. The goal of this review was to assess the evidence on factors that predict the length of absence among workers who are at the beginning of a sick leave related to low-back pain. The review looked at factors related to the injury, the job and the psychosocial work environment. This systematic review updated a previous review published in 2005.
To help ensure that their research makes a difference, research organizations are committing more time and resources to knowledge transfer and exchange (KTE) the practice of putting relevant research into the hands of key decision-makers and stakeholders in a timely, accessible and useful manner. Yet, the effectiveness of current KTE practices has not been routinely or consistently evaluated. In part, this could be because of the lack of instruments for assessing the impact of KTE activities. This systematic review sought to fill this gap. It looked across a wide variety of research fields to identify tools that can accurately and reliably measure how well KTE activities bring research evidence to practitioners and change their knowledge, attitudes and/or behaviour.
Studies have found that young workers are more likely than older workers to sustain work injuries. As a result, significant resources have been spent on young worker safety programs. However, these programs were developed without a comprehensive look at the factors that lead young workers to get injured. IWH undertook a systematic review to determine what factors are associated with work injury and illness among young workers.
The aging workforce is leading to increased attention being paid to the health of aging workers. Reviews show that older workers’ health and well-being benefit from work participation in “good work.” This project synthesized the literature on return to work in older workers to identify factors that help them stay employed, avoid reinjury and successfully return to work. The project evaluated the success of existing interventions and proposed new areas of focus.
Injuries to the upper extremity are common among workers, accounting for about 30 per cent of lost-time claims in Ontario in 2006. The upper extremity includes the neck, shoulder, upper arm, elbow, forearm, wrist and hand. This systematic review looked at the effectiveness of interventions to prevent upper extremity disorders and traumatic injuries.
Abuse of prescription opioids is a serious public health and safety problem in North America. At the time of this project, there had been no collection, analysis and synthesis of strategies aimed at improving the appropriate use of prescription opioids and reducing misuse, abuse, addiction and opioid-related deaths. This information was desperately needed to stem the current opioid crisis. This comprehensive systematic review of the research literature helped fill this void, thus helping prevent a duplication of efforts in the development of strategies to promote appropriate use of prescription opioids.
Employment experiences during the "young adult" phase of life are critical to determining a person’s career trajectory. During this life phase, young adults report a number of vocational transitions, including graduating from school and finding and sustaining paid work. Challenges with employment during young adulthood can have long-term consequences, such as the risk of future unemployment or underemployment, reduced earnings and/or a deterioration of skills.

To date, much of the research on the employment of young adults with disabling health conditions has focused on the impact of health factors (e.g. disability type, disease severity, activity limitations), demographic characteristics (e.g. education, gender) and psychosocial perceptions (e.g. perceived social support, autonomy). It is unclear to what extent studies have examined the role of organizational conditions (e.g. availability of workplace accommodations, modifications and supports), training needs (e.g. skills building, vocational readiness), disability services (e.g. vocational rehabilitation) and policy-level factors (e.g. incentives to hire disabled young adults, enforcement of duty-to-accommodate legislation) that may be influential in facilitating the employment participation of young adults living with disabilities.
Effective decision-making in occupational health and safety (OHS) requires having up-to-date evidence on what works from the best available research at hand. However, the research literature does not typically take into account how implementation may be constrained by the demographic, economic or resource context of a jurisdiction/region that is considering action. Evidence-informed practices and policies need to be made based not only on an understanding of ‘what works,’ but also on an understanding of ‘what will work here.’ The purpose of this project was to develop and test an innovative methodology for synthesizing current scientific knowledge and tailoring it for use in specific provincial and local contexts.
Over the last decade, the Institute for Work & Health has produced a series of systematic reviews on what workplace-based policies, practices and approaches support return to work (RTW) and recovery for injured and/or ill workers. However, important information gaps remain regarding the effects of regulatory, system-based strategies focused on disability management. This project seeks to address this knowledge gap by conducting a systematic review of the literature that answers this specific research question: What system-based RTW and work disability management/support interventions are effective in assisting workers with musculoskeletal, mental health and pain-related conditions with their return to work and recovery after a period of work absence?
Arthritis is among the most prevalent chronic health problems in Canada. It is estimated to affect more than 4.4 million people, which makes it the leading cause of physical disability in Canadian adults. Although often thought of as a disease of aging, about 60 per cent of people with arthritis are under age 65, with most being in their prime earning years (ages 45+). As a result, costs for arthritis are high. In 2000, the estimated burden of the disease in Canada was $6.4 billion per year, with two thirds ($4.3 billion) being indirect costs largely related to productivity losses and long-term disability. Osteoarthritis (OA) is the most common type of arthritis and ranks among the top ten causes of disability world-wide. Of increasing interest are personal and environmental factors that may contribute to the development of OA or aggravate its trajectory over time, particularly the role of occupational activities. This systemic review examined the research evidence to see if there is an association between OA and work.
The most common occupational health complaints among computer users are eye discomfort and musculoskeletal disorders (MSDs), including sustained pain in the neck and upper extremities. Researchers from the Institute for Work & Health (IWH), in collaboration with researchers from the United States, undertook a systematic review to identify studies that evaluated the effects of workplace interventions on visual or upper-body musculoskeletal symptoms and disorders among computer users. The goal was to provide scientifically credible evidence about how to reduce the health risks associated with computer work.
Employers, insurers and workers have expressed a growing interest in workplace-based return-to-work (RTW) intervention studies. To provide a comprehensive summary of the most effective workplace-based RTW interventions and to direct future research priorities in this area, the Institute for Work & Health conducted a systematic review of the return-to-work literature published since 1990. The systematic review was initiated at the request of Ontario's Workplace Safety and Insurance Board. Researchers sought to answer the following question: "What workplace-based return-to-work interventions are effective and under what conditions?"

Ongoing systematic reviews

Listed below are systematic reviews that are ongoing or completed so recently that findings are just beginning to emerge.

In 2019, Canadian women 15 years and older represented nearly half (47.4 per cent) of the labour force, compared to 37.6 per cent in 1976—a percentage increase of over 15 per cent. Yet much of our understanding of work exposures is still male-centric. Social (gender) and biological (sex) differences can affect the health of men and women in different ways.

This is particularly true in the case of workplace-acquired communicable diseases (that is, illnesses caused by an infectious agent). Social factors such as the types of jobs and industries in which men and women work can influence their exposure to communicable diseases. For example, men are more likely to work in outdoor environments (such as forestry and farm work) and are more likely to be exposed to tick-borne infections. The gendered nature of front-line and essential work, which became apparent in the COVID-19 pandemic, can also lead to different infection transmission/exposures in men and women. Biological factors related to differences in immunity to infections also can affect how likely men and women are exposed to communicable diseases in their workplaces.

While gender/sex considerations are increasingly included in work and health research, they are not often the focus of studies reporting patterns of workplace-acquired communicable disease exposure.