A new approach for detecting work-related disease risks: the Occupational Disease Surveillance System

MacLeod J, McLeod C, Peter A, Logar-Henderson C, Shakik S, Sritharan J, Dakouo M, Demers P. Journal of the Ontario Occupational Health Nurses Association Fall/Winter 2018; 37(2):45-51.

Although workplace exposures are increasingly recognized as important contributors to disease, there is no systematic approach in Ontario to detect existing and emerging trends in work-related disease, or to efficiently identify or monitor groups of workers that are at risk. The Occupational Disease Surveillance System was created to address these limitations and generates statistical information to characterize the associations between hundreds of different jobs and cancers and non-malignant diseases.

A cohort of about 2.2 million workers was identified from Workers Safety Insurance Board (WSIB) claims accepted from 1983 to 2014. These workers were linked to the Ontario Cancer Registry (1964-2016), and a subset were subsequently linked to the Ontario Health Insurance Plans eClaims database (1999-2016), the Canadian Institute for Health Information’s Discharge Abstract Database (2006-2016) and the National Ambulatory Care Registry (2006-2016). Workers were followed from entry into the cohort, corresponding to the date of their first WSIB accepted lost-time claim, until disease diagnosis, emigration from Ontario, date of death or end of follow-up (December 31, 2016), whichever occurred first. Cox proportional hazard models were used to generate age- and sex-adjusted hazard ratios (HR) and 95% confidence intervals (CI), which estimate the risk of disease in a particular occupation or industry group compared to all other workers.

The ODSS detected similar associations for most industries (12/13) and occupations (15/16) with known increased risk, including workers employed in mining (HR=1.43, 95% CI=1.30-1.57), construction (HR=1.09, 95% CI=1.04-1.14), and transportation (HR=1.14, 95% CI=1.09-1.19), demonstrating the validity of the ODSS as a surveillance tool. It has subsequently been used to characterize these associations for many other health outcomes, including breast cancer in both men and women, asthma, contact dermatitis, and silicosis.

Timely information about work-related disease is crucial to support prevention initiatives to protect workers. This novel linkage approach identifies existing and emerging trends in occupational disease in Ontario, and can provide evidence to inform screening programs, clinical approaches, compensation policies, regulations, and risk reduction initiatives by employers, government agencies, and other stakeholders. This system serves as a model for other jurisdictions, and for a national approach to occupational disease surveillance, with the ultimate goal of reducing risks among workers through improved risk reduction and prevention.