PT - JOURNAL ARTICLE AU - Sarah A Buchan AU - Peter M Smith AU - Christine Warren AU - Michelle Murti AU - Cameron Mustard AU - Jin Hee Kim AU - Sandya Menon AU - Kevin A Brown AU - Trevor van Ingen AU - Brendan T Smith TI - Incidence of outbreak-associated COVID-19 cases by industry in Ontario, Canada, 1 April 2020–31 March 2021 AID - 10.1136/oemed-2021-107879 DP - 2022 Jan 12 TA - Occupational and Environmental Medicine PG - oemed-2021-107879 4099 - http://oem.bmj.com/content/early/2022/01/11/oemed-2021-107879.short 4100 - http://oem.bmj.com/content/early/2022/01/11/oemed-2021-107879.full AB - Objectives The objective of our study was to estimate the rate of workplace outbreak-associated cases of COVID-19 by industry in labour market participants aged 15–69 years who reported working the majority of hours outside the home in Ontario, Canada.Methods We conducted a population-based cross-sectional study of COVID-19 workplace outbreaks and associated cases reported in Ontario between 1 April 2020 and 31 March 2021. All outbreaks were manually classified into two-digit North American Industry Classification System codes. We obtained monthly denominator estimates from the Statistics Canada Labour Force Survey to estimate the incidence of outbreak-associated cases per 100 000 000 hours among individuals who reported the majority of hours were worked outside the home. We performed this analysis across industries and in three distinct time periods.Results Overall, 12% of cases were attributed to workplace outbreaks among working-age adults across our study period. While incidence varied across the time periods, the five industries with the highest incidence rates across our study period were agriculture, healthcare and social assistance, food manufacturing, educational services, and transportation and warehousing.Conclusions Certain industries have consistently increased the incidence of COVID-19 over the course of the pandemic. These results may assist in ongoing efforts to reduce transmission of COVID-19 by prioritising resources, as well as industry-specific guidance, vaccination and public health messaging.No data are available. Public Health Ontario (PHO) cannot disclose the underlying data. Doing so would compromise individual privacy contrary to PHO’s ethical and legal obligations. Restricted access to the data may be available under conditions prescribed by the Ontario Personal Health Information Protection Act, 2004, the Ontario Freedom of Information and Protection of Privacy Act, the Tri-Council Policy Statement: Ethical Conduct for Research Involving Humans (TCPS 2 (2018)) and PHO privacy and ethics policies. Data are available for researchers who meet PHO’s criteria for access to confidential data. Information about PHO’s data access request process is available on-line at https://www.publichealthontario.ca/en/data-and-analysis/using-data/data-requests. Access to the anonymised microdata for the Labour Force Survey Supplement is available through Statistics Canada to accredited researchers and government employees for research purposes.