WSIB fundamentally changed the original mandate of Ontario’s system – to compensate for injury – when it brought in its 2014 pre-existing conditions policy. This new policy allowed the Board to deny benefits by blaming disabilities on age-related “degeneration” and other pre-existing conditions rather than on the work injury – even if these conditions had not affected worker’s ability to do the job or had shown no symptoms (were asymptomatic).
Policy looks to deny
This sabotages:
- the accepted standard causation test of whether the work was a “significant contributing factor” in the development of the condition (workplace injury has only to be an important, but not the sole factor), and
- the “thin skull rule” (this means ‘take the worker as you find him/her’. A worker should not be penalized because of a pre-existing condition that did not affect her capacity to do the job but made her vulnerable to greater injury than another worker).
Despite a “cautious step forward” more action is needed
The injured worker community, legal representatives and labour waged an intensive fight-back campaign. A class action lawsuit and media spotlight also focussed attention on the issue. In December 2017 the WSIB issued a policy clarification, announcing that the Board will no longer reduce non-economic loss (NEL) awards for injured workers as a result of non-symptomatic pre-existing conditions, and will reconsider NEL lump sum settlements that were awarded and then reduced based on asymptomatic pre-existing conditions.
However further action is needed. These latest changes to the policy apply differently to decisions made before or after 2014; largely disregard psychological conditions; fail to address the needs of those already denied a NEL award and of the many denied wage-loss benefits because of asymptomatic pre-existing conditions.

- Molina, Kimberley. 2023 Apr. 12. “Advocates want WSIB to reverse policy on pre-existing conditions.” CBC News
- Buonastella, Orlando & David Neberry. 2018 Feb. 25. “Changes to WSIB pre-existing conditions policy a cautious step forward.” RankAndFile
- Mojtehedzadeh, Sara. 2017 Dec. 15. “WSIB to Abolish Policy that Slashed Benefits for Thousands.” Toronto Star
- Ontario Network of Injured Workers’ Groups. 2017 Sep. Workers’ Comp Is a Right: We Demand Stop Cutting Benefits Based on Pre-existing Conditions.
- Yachnin, Maryth. 2017 Jun. No Evidence: the Decisions of the Workplace Safety and Insurance Board. Toronto: IAVGO Community Legal Clinic
- Burke, Ashley. 2016 Oct. 27. “WSIB’s ‘devastating’ compensation policy all about Board’s bottom line, lawyers charge: some injured workers have had benefits cut by half since pre-existing conditions policy came into effect.” CBC News Ottawa
- Injured Workers’ Consultants. 2014, Apr. 30. Submissions on WSIB Draft Policies. Toronto: IWC