The purpose of this policy is to outline how WorkSafeNB gathers and weighs medical evidence during the adjudication of occupational disease claims.
This policy applies to all claims for compensation involving occupational diseases.
1.0 General Statements
WorkSafeNB uses Section 7 of the Workers’ Compensation Act (WC Act) and Policy 21-100 Conditions for Entitlement – General Principles to adjudicate all claims for compensation involving a personal injury caused by accident arising out of and in the course of employment, including claims for occupational diseases.
The WC Act defines an accident as a:
Occupational diseases are illnesses that an injured worker may develop as a result of certain exposures, and are peculiar to or characteristic of a particular industrial process, trade or occupation. Occupational diseases or related disablements may have occurred over time, and may have resulted from an exposure with one employer or from multiple exposures at various workplaces. Regulation 84-66 outlines some diseases that are known to be work-related, however these diseases are not exempt from WorkSafeNB’s adjudication process to determine if the disease arose out of and in the course of employment.
In order to accept a claim for compensation, WorkSafeNB must determine that the disease is an occupational disease that arose out of and in the course of employment. To determine this, WorkSafeNB:
2.0 Medical and Scientific Evidence of Causation
WorkSafeNB considers medical evidence to be the most important factor for establishing if a work-related exposure could have caused the disease. When evaluating medical information, WorkSafeNB uses a method that is:
This means that WorkSafeNB’s evaluation of medical information and the resulting conclusions:
For more information on the types of medical and scientific literature WorkSafeNB accepts, see Policy 25-014 Medical Aid Decisions.
To determine any causal association between an exposure and a disease, WorkSafeNB gathers and weighs evidence to answer the following two questions:
2.1 Determining Association Between the Exposure and the Disease
WorkSafeNB applies the Bradford Hill criteria to its analysis of medical and scientific literature to determine any causal association between the exposure and the disease. The Bradford Hill criteria is a tool that was developed to interpret epidemiological evidence of a general causal relationship between exposure to an agent and the disease. Specifically, WorkSafeNB uses this criteria to determine:
If the criteria supports a causal association between the exposure and the disease, then WorkSafeNB determines the strength of association in terms of the Attributable Risk Fraction.
An Attributable Risk Fraction of:
2.2 Determining If the Specific Exposure Caused the Disease
After WorkSafeNB has analyzed the medical and scientific literature and is satisfied that there is a probable causal association between the exposure and the disease, WorkSafeNB then proceeds to confirm if the:
At this stage, WorkSafeNB examines the specific facts and information of the claim to determine if it is reasonable that the worker’s disease arose out of and in the course of employment, including:
WorkSafeNB analyzes all information related to the claim in order to make a decision. When the preponderance of evidence weighs more heavily toward the disease being work-related, WorkSafeNB accepts the claim.
For more information on the process used to adjudicate claims, see Policy 21-100 Conditions for Entitlement – General Principles.
3.0 Determining the Date of Accident
Date of accident for hearing loss is determined using Policy 21-112 Occupational Hearing Loss.
For other occupation diseases, other than occupational hearing loss, the date of accident is the date when disablement as a result of the occupational disease first occurred. When there is no evidence of disablement, WorkSafeNB uses the date of diagnosis as the date of accident.
Accident - includes a wilful and intentional act, not being the act of a worker, and also includes a chance event occasioned by a physical or natural cause, as well as a disablement caused by an occupational disease and any other disablement arising out of and in the course of employment, but does not include the disablement of mental stress or a disablement caused by mental stress, other than as an acute reaction to a traumatic event (WC Act)
Appeals Tribunal – means the Workers’ Compensation Appeals Tribunal established under the WHSCC & WCAT Act.
Attributable Risk Fraction – is a figure derived from the overall strength of association and is a measure of the proportion of cases of the disease that are reasonably attributable to the exposure.
Evidence to the contrary – any information that may suggest the accident or injury, including occupational disease, did not arise out of and in the course of employment.
Occupational disease – any disease, which by the regulations, is declared to be an occupational disease and includes any other disease peculiar to or characteristic of a particular industrial process, trade or occupation (WC Act)
Preponderance of evidence – the most persuasive and impressive information on one side of a case that outweighs the information on the other side. A preponderance of evidence is not decided on the quantity of information alone, but on the significance and strength of the evidence as well.
WorkSafeNB – means the Workplace Health, Safety and Compensation Commission or "the Commission" as defined by the WHSCC & WCAT Act.