Occupational disease policy framework

1. Introduction

The Occupational Disease Policy Framework is the foundation for occupational disease policy development at the WSIB. The framework guides the WSIB in identifying occupational diseases and recognizing them within regulation and policy.¹ It reflects the WSIB’s commitment to an occupational disease policy process that is systematic, transparent, and informed by high-quality scientific evidence.

The framework:

• describes the WSIB’s approach to the development and updating of occupational disease regulation and policy
• identifies the WSIB’s legislative authority for developing this occupational disease policy guidance under the Workplace Safety and Insurance Act, 1997 (WSIA)
• facilitates the creation of clear and updated policy guidance to support timely and consistent decision-making in occupational disease claims, to help the WSIB fulfill its legislative obligations to workplace parties

1.1. Background

In 1910, Sir William Meredith was appointed to lead a Royal Commission to look into the issue of workers’ compensation in Ontario. The Royal Commission’s final report, known as the Meredith Report, was released in 1913. Subsequently, legislation was passed creating the Workmen’s Compensation Act in 1914.

The Meredith Report is known for proposing that the workers’ compensation system be established on the principles of no fault compensation, collective liability, security of payment, exclusive jurisdiction, and an independent board. Less widely known, the Meredith Report also recommended that a workers’ compensation system should provide equal access to benefits for physical injuries and industrial diseases (now “occupational diseases”).

All of these principles are reflected in the WSIA, and a worker who experiences an occupational disease “due to the nature of their employment” is entitled to the same WSIB benefits and services as a worker who sustains a “personal injury by accident”. Both injury and disease claims involve answering the key question of whether employment played a causal role in their injury or disease. When an occupational disease is determined to be due to the nature of the worker’s employment, the disease is considered “work-related.”

Determining causation is often complex in occupational disease claims, as many diseases result from a wide range of contributing factors, both occupational and non-occupational. With long-latency diseases, the effects of these contributing factors may take years or decades to result in illness.

To address this challenge, the WSIB relies on scientific evidence, generally drawn from peer-reviewed published research, to identify occupational diseases and recognize them in regulation and policy where there is sufficient evidence to do so. The most persuasive evidence of the association between occupational exposure and disease is provided through well-conducted epidemiological studies. The role of scientific evidence in occupational disease policy development has been repeatedly acknowledged in Ontario over the last forty years by a number of seminal reports.² The current model for reviewing scientific evidence is rooted in the Occupational Disease Advisory Panel (ODAP) Chair’s Final Report.³ The Chair’s final report recommended relying on the available scientific evidence to develop regulation and policy, while continuing to evaluate the scientific evidence, confirming or updating policy guidance as appropriate. The Using Scientific Evidence and Principles to Help Determine the Work-relatedness of Cancer⁴ and the Value for Money Audit Report: Occupational Disease and Survivor Benefit Program⁵, similarly recommended using evolving scientific knowledge to support occupational disease policy development.

Where there is strong and consistent scientific evidence that a disease is causally linked to a particular occupational risk factor such as an exposure to a substance relating to a particular process, trade or occupation in an industry, an occupational disease may be recognized and set out in regulation or policy. This recognition avoids the repeated effort of analyzing the scientific evidence for a causal link in each individual claim, and streamlines the adjudicative process to simplify the determination of work-relatedness. The framework guides these efforts to support and streamline decision-making.

2. Occupational disease legislative and policy scheme

2.1. Legislation

Ontario’s first workers’ compensation act came into effect in 1915. At that time, disease compensation was limited to six listed occupational diseases. Since then, Ontario’s compensation system has undergone a number of reforms, and the treatment of occupational disease within the legislation has evolved and expanded. The current legislation, the WSIA, applies to workplace accidents occurring on or after January 1, 1998. The WSIB also administers prior workers' compensation acts.

As an administrative tribunal, the WSIB derives all of its powers and duties, explicitly or implicitly, from the WSIA. In relation to occupational disease, the legislation sets out parameters for a holistic scheme; from defining and identifying occupational diseases to empowering the WSIB to recognize occupational diseases in both regulation and policy. The WSIA:

• sets out a five part definition of occupational disease,⁶
• requires monitoring of scientific developments so that evidence linking workplace processes or exposures and disease outcomes is reflected in policy guidance as appropriate,⁷
• recognizes certain occupational diseases directly in legislation,
• sets out powers to recognize occupational diseases in regulation and policy,⁸ and
• makes clear that a worker who experiences an occupational disease due to the nature of their employment, is entitled to the same WSIB benefits and services as a worker who experiences a personal injury by accident.⁹

2.2. Regulation: presumptions and schedules

Regulation has the force of law but must be authorized by a specific provision in legislation. Pursuant to the WSIA and subject to the approval of the Lieutenant Governor in Council, the government of Ontario and the WSIB each have the power to make regulations. Those made by the WSIB require collaboration with the government.

Under the WSIA, regulations may be employed to recognize occupational diseases in a variety of ways, though in recent years have been used to establish presumptions of work-relatedness. The purpose of a presumption is to recognize the work-relatedness of an occupational disease and streamline the evidence gathering required for determining entitlement in a claim.

Distinct regulations may be enacted by the government, such as the firefighter cancer regulation (O. Reg. 253/07) which recognizes a number of cancers as presumed to be work-related due to the nature of firefighter employment, and sets out criteria for applying the presumption.

In collaboration with the government, the WSIB may choose to use its regulation making authority to recognize occupational diseases in Schedules 4 and 3 of the General Regulation (O. Reg. 175/98). The schedules list the occupational diseases that are presumed to be work-related where a worker contracts the listed disease and was employed in the corresponding process.

Occupational disease presumptions under both schedules reflect strong and consistent scientific evidence supporting a link between an occupational process and disease outcome. The scientific findings are considered along with the appropriate legislative requirements, legal principles and policy considerations to determine whether to recognize an occupational disease in regulation.

Schedule 4 creates a non-rebuttable presumption of work-relatedness. In these cases, the scientific evidence supports that in virtually every case, the disease occurrence is linked to a single cause and that cause is associated with a work process. For example, mesothelioma due to asbestos exposure meets this criterion.

Schedule 3 creates a rebuttable presumption of work-relatedness. The scientific evidence in these cases supports a multicausal association with the disease, one cause being occupation. This acknowledges that other causes play a role and in some cases, may ultimately be the more likely cause of the disease. In these cases, the presumption may be rebutted by the decision-maker where it can be shown that the disease did not occur due to the nature of the worker’s employment. If the scientific evidence shows that the risk of disease is high only in certain processes and the processes can be readily described, they are considered for a Schedule 3 entry. For example, tuberculosis in health care sector processes meets this criterion.

2.3. Operational policy

The WSIB has the power to develop policies under its governing legislation and supporting regulations. This authority is set out in the WSIA both explicitly in s.159 and implicitly in various other provisions throughout.

Occupational disease policies are developed to recognize occupational diseases and streamline initial entitlement adjudication by providing criteria and guidance to decision-makers to support timely and consistent decision-making.

Similar to Schedules 4 and 3, policies reflect strong and consistent scientific evidence supporting a link between an occupational risk factor and a disease outcome. Generally, an occupational disease is addressed in policy when the scientific evidence isn’t specific enough to pinpoint a work process as required for scheduling, or the incidence of the disease within an occupation, trade or industry isn’t significant enough to support a presumption.

The scientific findings are considered along with the appropriate legislative requirements, legal principles and policy considerations to determine whether to recognize an occupational disease in policy. Compared to scheduling, developing a policy affords a more flexible approach for drawing broad guidelines for adjudication. Policies can focus on specific subgroups, levels of exposure, latency periods, and occupational categories to support decision-making where a work process cannot be defined to support schedule entry.

Note: References to both the schedules and policies will be referred to as policy guidance throughout this framework.

2.4. Recognition of occupational disease

As noted above, where there is strong and consistent scientific evidence that a disease is causally linked to a particular occupational risk factor such as an exposure to a substance relating to a particular process, trade or occupation in an industry, the WSIB may recognize this in regulation or policy. Recognizing an occupational disease in this way, streamlines the adjudicative process by avoiding the repeated effort of obtaining and analyzing scientific and other evidence of a causal link for each individual claim. This recognition answers the question of whether an injury or disease is an occupational disease under the WSIA but may also set out other guidance to simplify the determination of work-relatedness by way of presumption or other policy criteria.

3. Occupational disease policy development

The WSIB is committed to ensuring occupational disease policy guidance is grounded in the fundamental objectives of the WSIA and reflects the best available scientific evidence and any relevant stakeholder and/or expert input. It is also committed to continually monitoring developments within the scientific evidence that may be relevant to understanding the relationship between occupational risk factors and disease.

These commitments are met through the steps of the occupational disease policy development process that are set out below. Policy guidance developed and implemented through this process will be:

• evidence-based and provide clear direction to users;
• fair, practical and effective to ensure it can be applied with timeliness, transparency and consistency;
• aligned with strategic direction, and
• fiscally responsible and ensure the long term-sustainability of the system.

Occupational disease policy development process

Consulation may occur at various stages of the OD policy development process

3.1. Issue identification

Occupational disease policy issues are those concerning the relationship between a disease, or group of diseases, and an occupational risk factor(s). The WSIB monitors occupational disease policy issues on an ongoing basis. Issues are identified in a number of ways, including through regular monitoring of scientific literature as required by the WSIA.

The main sources of potential issues are:

• The workplace safety and insurance system: issues from this source may arise from legislative or regulatory changes, external stakeholder input, the WSIB’s Scientific Advisory Table on Occupational Disease, relevant WSIAT decisions or court decisions, trends in WSIB claims data, and the identification of a cohort of claims with a single employer or within an industry.
• The occupational health and safety system: issues from this source may arise from government prevention efforts related to workplace injuries and diseases, research centres, such as the Institute of Work & Health, Occupational Cancer Research Centre (OCRC), and Centre for Research Expertise in Occupational Disease and trends in surveillance data (e.g., Occupational Disease Surveillance System reports).
• The wider scientific and workers’ compensation communities: issues from this source may arise from scans of the scientific literature, research from reputable agencies, such International Association for Research on Cancer (IARC); National Institute for Occupational Safety and Health (NIOSH), and the National Academies of Sciences, Engineering, and Medicine (NASEM), and other workers’ compensation systems.

Issues are targeted for further investigation when the WSIB becomes aware of a possible association between an occupational risk factor and a disease, or when the WSIB learns of significant new science relating to an existing schedule entry or occupational disease policy.

3.2. Prioritization and agenda setting

Each year the WSIB publishes a policy agenda describing the policy items, including occupational disease issues that the WSIB plans to review in the upcoming year. A policy agenda may identify new policy projects, as well as provide updates about ongoing policy projects.

Evaluating occupational disease issues for inclusion in a policy agenda begins with the review and ranking of all identified issues that the WSIB has been monitoring. To perform this ranking, the WSIB considers general policy prioritization factors along with those unique to occupational disease. Prioritization factors that may be relevant include:

• alignment with legislative/regulatory provisions
• a known change in the state of the scientific evidence on the association between the disease and occupational risk factor
• WSIAT decision trends and court rulings
• external stakeholder input and feedback
• the burden of the disease in Ontario (i.e., incidence and prevalence)
• the number of WSIB claims related to the disease
• administrative or operational considerations
• organizational strategic direction and priorities

Once the prioritization exercise is complete, the WSIB determines the number and combination of new items it is feasible to undertake over the upcoming year(s), taking into account work carried over from previous years, recurring work, and unanticipated high-priority issues.

Timelines for occupational disease policy projects can vary widely depending on the nature of the disease issue. In large part, this is due to the time it takes to gather and review the scientific evidence. It is not uncommon for evidence-gathering to take longer than a year and, in some cases, may take several years, followed by analysis and development of new or revised policy guidance.

In some cases, the WSIB may consult with external stakeholders and/or subject matter experts to determine which issues to address in the upcoming year(s).

3.3. Research and analysis

In the research phase, occupational disease policy issues are framed in a clear manner in order to develop the research question that needs to be addressed. An appropriate research question will narrow down the area of study and enable a comprehensive review of the scientific literature and may inform the gathering of other relevant policy information. To help identify and refine the research question, the WSIB may seek input from internal subject matter experts, as well as the WSIB’s Scientific Advisory Table on Occupational Disease.

Gathering scientific evidence

Scientific evidence is gathered to answer the research question. Generally, the WSIB is interested in exploring whether there is a causal relationship between the disease in question, and an occupational risk factor, such as whether work processes involving asbestos are causally related to lung cancer.

The WSIB typically relies on a research approach referred to as a systematic review to gather the highest quality of evidence available to determine a causal relationship. A well-conducted systematic review relies on rigorous methods to gather and critically appraise the relevant scientific evidence. This type of review collects, analyzes, and synthesizes the evidence to assess the association between an occupational risk factor and disease. In all cases, the scientific review is also vetted through peer review to check its validity and quality.

The WSIB leverages this existing methodology as it is widely accepted in the research community that there is a hierarchy of evidence with systematic reviews and meta-analyses ranking as the highest quality of evidence, above observational studies, while expert opinion and anecdotal evidence, for example, represent lower quality evidence¹⁰. Organizations such as the World Health Organization, Health Canada, and WorkSafeBC regularly rely on systematic reviews to ensure access to high quality evidence.

It may not always be necessary for the WSIB to commission a new systematic review. If current, relevant, high-quality, peer-reviewed scientific evidence already exists, the WSIB may decide, with the input of the WSIB’s Scientific Advisory Table on Occupational Disease, to rely on this evidence instead of commissioning a new systematic review.¹¹ Existing high-quality scientific evidence may include systematic reviews, research from a reputable agency (e.g., OCRC, NIOSH, IARC, other workers’ compensation boards), high-quality studies, or a combination of this evidence.

This approach to gathering scientific evidence provides the WSIB with timely and the best available scientific evidence to support its analysis of occupational disease policy issues for the purposes of policy development.

Gathering other policy information

In addition to scientific evidence, other relevant information is gathered to assess all of the dimensions of the occupational disease policy issue and support policy development. This may include, but is not limited to:

• legal considerations and appeals trends
• existing internal and external feedback
• approaches taken by other workers’ compensation systems on the same or a similar issue and the basis for that approach
• current practices and experience in adjudicating WSIB claims on the disease
• Ontario’s economic and industrial history to identify past workplace exposures relevant to the outcome and to understand the workplaces at risk for this outcome and the anticipated numbers of claims resulting from the exposures in those workplaces.

Analysis

Once gathered, the relevant scientific evidence and other policy considerations are reviewed by the WSIB to assess whether the development of new policy guidance or revision to existing guidance is supported.

If the disease is not a recognized occupational disease – i.e., it is not the subject of an existing schedule entry or policy, or otherwise formally recognized by the WSIB as an occupational disease – the WSIB considers whether the findings of the systematic review support a causal relationship between the occupational risk factors and the disease outcome.

In the analysis phase, the WSIB relies on scientific and policy expertise to interpret the scientific evidence. In deciding when to recognize an occupational disease, it is important to acknowledge that a body of research does not produce a single measure of association but rather a range of results that need to be considered. Policy analysis may confront issues such as how to assess scientific information that may be contradictory or inconclusive, or that is based on results of exposures that are not comparable with Ontario workplaces.

Where a causal relationship is supported, the WSIB will take into account the statutory definition of “occupational disease”, the strength and consistency of the scientific evidence on causation, and any other relevant legal and policy considerations, to determine whether the disease should be recognized as an occupational disease.

Where the outcomes of the research and analysis phase support recognition of an occupational disease, the WSIB will determine whether scheduling or operational policy is most appropriate, taking into account the established thresholds.

3.4. Recognizing an occupational disease: scheduling and policy

There is a hierarchy of policy options for recognizing an occupational disease in regulation or policy. All three options require strong and consistent scientific evidence of a causal link. They provide a range of options to reflect the strength of association and are intended to streamline decision making where the evidence supports the high likelihood of the disease being work-related.¹²

Scientific evidence will generally be considered “strong and consistent” when multiple (i.e., two or more) high-quality studies find a statistically significant positive association between an occupational risk factor and a disease. A measure of association (e.g., relative risk) of two or more is a common indicator of a strong positive association. However, the WSIB may accept, as sufficient, a finding of less than two, but more than one, when multiple high-quality studies find a similar magnitude of excess risk.

The WSIB considers the following thresholds when selecting the appropriate policy approach for an occupational disease:¹³

Threshold for entry in schedule 4

Diseases may be entered in Schedule 4 when there is strong and consistent scientific evidence that, in virtually every case, the disease occurrence is linked to a single cause and that cause is associated with an occupational risk factor.

Since the presumption of entitlement in Schedule 4 cannot be rebutted there should be little or no evidence of non-work exposure that would override the work exposure in individual claims in practice.

Threshold for entry in schedule 3

Diseases may be considered for entry in Schedule 3 when there is strong and consistent scientific evidence supporting a multicausal association with the disease, with one or more causes being an occupational risk factor.

Entry in Schedule 3 will be appropriate when the scientific evidence shows the risk of disease is increased in certain occupational processes (i.e., high-risk subgroups) and the processes can be clearly articulated. However, if work-relatedness in individual claims is often rebutted because the disease is common in the general population and often attributable to non-occupational risk factors, operational policy may be the more appropriate tool to use.

Threshold for development of operational policy

Operational policy may be developed when there is strong and consistent scientific evidence supporting a single or multicausal association with the disease, with at least one cause being an occupational risk factor.

Policies typically focus on situations where the link may be relevant across many occupational settings rather than tied to a single identifiable process. To support a more flexible approach, policies may include specific subgroups, levels of exposure, minimum latency periods, and occupational categories that do not meet the requirements for scheduling.

Thresholds for entry in a schedule or development of policy not met

Where the scientific evidence is inconclusive or too inconsistent to meet the thresholds for scheduling or policy, the WSIB may develop support documents that summarize the scientific findings, which can be used by decision-makers in the case-by-case adjudication of individual claims. When determining initial entitlement in such claims, decision-makers gather and weigh all the available evidence, including medical and scientific, employment and exposure history, and relevant personal information.

3.5. Drafting

The drafting process for schedules involves describing the disease and the corresponding process that results in a presumption of work-relatedness. Drafting a new schedule entry or revising an existing one involves collaboration with government as schedule changes ultimately require a regulatory amendment.

For operational policy, the drafting process is more complex and will generally include more extensive entitlement criteria that are needed to support decision-making where a work process cannot be clearly defined, such as exposure, latency, variety of occupational settings or industries.

3.6. Implementation

The WSIB undertakes a number of activities leading up to the implementation of a new schedule entry or publishing of a policy. This may include system updates, staff training, and posting information to the WSIB’s website to advise stakeholders and workplace parties of changes. These activities ensure a smooth and seamless implementation of the new or revised policy guidance.

3.7. Monitoring of evidence and updating policy guidance

The WSIB continually monitors developments within the scientific evidence that may be relevant to understanding the relationship between occupational risk factors and disease outcomes. Ongoing research by the scientific community means new scientific evidence may emerge that did not exist at the time an occupational disease policy issue was last reviewed.

An opportunity for updating policy guidance is generally identified when the WSIB learns of significant new scientific evidence concerning an existing occupational disease schedule entry or policy. The processes for policy development outlined above are then followed to determine whether an occupational policy issue is reviewed, and if appropriate, policy guidance may be updated.

Any updates to existing policy guidance will reflect the body of scientific evidence, including any evidence that has emerged since the guidance was developed or last reviewed. This may involve updating entitlement criteria within a policy or upgrading a policy to a schedule entry where the evidence supporting the causal relationship has become stronger. Where the evidence has become weaker or is no longer consistent, policy guidance may no longer be supported by the available scientific evidence.

4. Consultation

Engagement with stakeholders and/or experts may occur at any phase, or at multiple phases of the process.

Generally, consultation will occur at the issue identification, prioritization and agenda setting, and research and analysis phases. In these phases, stakeholder and expert input may assist in the identification or prioritization of emerging occupational disease policy issues, while expert advice is intended to support the gathering and interpretation of scientific evidence during the research phase.

The WSIB recognizes and values the benefits of consultation in the policy development process. Stakeholder and expert input supports the development of occupational disease policy guidance that is current, evidence-based, and viewed as legitimate by those it impacts.

Consultation on occupational disease policy issues will generally be targeted due to their complexity. Targeted consultation seeks feedback and input from a specific group of employers or workers, or individuals or bodies with relevant expertise or specialized knowledge.

When the WSIB engages with stakeholders and/or experts, it will identify the relevant stakeholders/experts and the method(s) of engagement, which can vary according to the issue, the timeframe for the project, and the capacity and resources of both the WSIB and those it seeks input from.

The relevant stakeholders and experts that the WSIB may engage with during the occupational disease policy development process include:

• workplace parties including workers, survivors, employers, and their representatives,
• the WSIB’s Scientific Advisory Table on Occupational Disease, and
• individuals or bodies with relevant expertise or specialized knowledge, such as scientific, clinical, and technical knowledge.

In some circumstances, the WSIB may determine consultation is not necessary because, for example, an amendment is made to the WSIA or an associated regulation by the government, and the WSIB is required to ensure the policies are consistent with the law and will act to make any policy revisions to achieve this as expeditiously as possible.

5. Conclusion

The WSIB continually monitors the evolving state of the scientific evidence to better understand causal relationships between occupational risk factors and disease outcomes. Where supported by the evidence, and in line with its legislative authority, the WSIB may recognize an occupational disease through policy or scheduling. The Framework guides the WSIB in these activities and ensures the policy development process is both transparent and based on high-quality scientific evidence.

¹ For greater clarity, this framework does not apply to the adjudication of individual claims.

² Weiler, Paul, Reshaping workers’ compensation for Ontario, (Toronto: Ministry of Labour, 1980); Weiler, Paul. Protecting the Worker from Disability: Challenges for the Eighties: A Report Submitted to Russell H. Ramsay, Minister of Labour (Ontario: April 1983); Cam Jackson. New Directions for Workers’ Compensation Reform (Ontario: Minister Responsible for Workers’ Compensation Reform, June 1996); Harry W. Arthurs. Funding Fairness: A Report On Ontario’s Workplace Safety and Insurance System (Ontario: Queen’s Printer for Ontario, 2012). 

³ Smith, Brock, Final Report of the Chair of the Occupational Disease Advisory Panel (February, 2005) (Occupational Disease Panel Report: WSIB) (ODAP Report).    

⁴ Demers, P.A. (2020) Using Scientific Evidence and Principles to Help Determine the Work-Relatedness of Cancer. Final Report. Occupational Cancer Research Centre, Ontario Health.

⁵ KPMG. (2019) Workplace Safety and Insurance Board - Value for Money Audit Report: Occupational Disease and Survivor Benefit Program.

⁶ Workplace Safety and Insurance Act, 1997, s.2.

⁷ Workplace Safety and Insurance Act, 1997, s.161.

⁸ Workplace Safety and Insurance Act, 1997, ss.183 and 159.

⁹ Workplace Safety and Insurance Act, 1997, s.15.

¹⁰Guyatt GH, Sackett DL, Sinclair JC, Hayward R, Cook DJ, Cook RJ. Users’ guides to the medical literature. IX. A method for grading health care recommendations. JAMA 1995;274:1800-4.

¹¹ “High quality” with respect to factors including study design, methodology, and reporting of results.

¹² The hierarchy of options and thresholds are drawn from the ODAP Report. See footnote 3 above.

¹³ For greater clarity, these thresholds do not apply in the case-by-case adjudication of individual claims.