Why was this study done?
Ontario workers who have previously experienced a work injury, particularly those in certain occupations, are at a higher risk of experiencing opioid harms than the general population. The rate of opioid harms has increased in the general Canadian population, but it is not clear if these increases are also reflected in an injured worker population, and whether any changes vary by occupation.
How was the study done?
Researchers investigated how rates of opioid harms have changed over time using a large database of workers in Ontario who had previously experienced a work-related injury. Known as the Occupational Disease Surveillance System (ODSS), the database was first developed by the Occupational Cancer Research Centre to monitor work-related diseases, by linking provincial health records to workers’ compensation claim data from the Workplace Safety and Insurance Board (WSIB).
For the study, the researchers included 1.7 million workers with approved lost-time claims. The claims were then linked to hospitalization and emergency department visit records between 2006 and 2022. The team were able to see whether these visits were related to opioid poisonings—often referred to as overdoses—or opioid-related mental and behavioural disorders, for example, dependence or withdrawal.
What did the researchers find?
Between 2006 and 2022, this group of workers had 15,277 emergency department visits and 5,125 hospitalizations for opioid poisonings. About half were accidental. There were also 19,724 emergency department visits and 4,778 hospitalizations for opioid‐related mental and behavioural disorders. Across all types of harms, the vast majority occurred among men, and harms were most common among workers aged 35 to 65.
Increasing rates of opioid poisonings
Overall, rates of emergency department visits for opioid-related poisonings increased by nearly 600 per cent between 2006 and 2022; that’s 12 per cent each year, on average. In 2006, there were 25 visits for opioid-related poisonings per 100,000 people. In 2022, this number rose to 175 visits per 100,000 people. The largest increases happened between 2015 and 2019, when the rates increased 35 per cent per year. Hospitalizations rose more modestly, by four per cent per year, on average.
Increases were greater among men, and those aged 15 to 44. The occupational group with both the largest increases and the highest rates of opioid poisonings in 2022 were workers in machining. These workers had a 19 per cent annual increase in emergency department visits leading to over 300 cases per 100,000 people in 2022. Other occupations with high rates as well as large increases included construction trades, materials handling, and product fabricating, assembling and repairing.
Increasing rates of opioid-related mental and behavioural disorders
Between 2006 and 2022, emergency department visits for opioid-related mental and behavioural disorders rose from 58 to 179 visits per 100,000 people per year. That’s an eight per cent increase per year, on average. Hospitalizations rose 12 per cent per year, increasing from eight cases per 100,000 people in 2006 to 47 cases per 100,000 people in 2022.
Similar to poisonings, increases were greater among men. They were also greater among workers aged 35 to 44. When examining occupation, the largest increases in emergency department visits were seen among workers in clerical jobs, materials handling, sales and construction trades.
Emergency department visits rose among workers in most occupations except for those in managerial, administrative, natural sciences, engineering and mathematics, social sciences, teaching, artistic, literary and recreational occupations. Rates decreased by four per cent among these groups.
What are the implications of the study?
Examining trends in opioid harms by occupation provides greater detail on who the high-risk groups are and where to prioritize the effort to reduce harms. For example, among workers who had experienced a work injury, one contributor to the higher rates seen among men could be the greater representation of men in occupations where opioid harms were more common, such as machining and construction.
These occupations are physically demanding, and when combined with a workplace injury, may lead to more opportunities for opioid use. Masculine norms may also promote working through pain rather than seeking help. In addition, men are more likely to use illicit drugs than women, making them more likely to encounter a contaminated drug supply.
Conversely, some occupations typically deemed low-hazard, including sales and clerical jobs, saw notable increases in harms. This could indicate that it’s not only physical hazards of a job but also psychosocial or organizational factors that may contribute to opioid harms. More research is needed to understand how these factors may contribute to harms.
What are some strengths and weaknesses of the study?
A strength of the study is the long period of follow-up time (17 years), and the large number of workers (1.7 million) included in the study. The large number of workers allowed the researchers to break down the rates of harms within specific occupational groups.
A weakness of the study is that the sample only consists of workers with an accepted lost-time workers’ compensation claim. This means the group of workers examined for the study are more commonly from occupations with high injury risks, where an injury would be severe enough to warrant a compensation claim. In addition, the occupation only reflects the occupation at the time of injury, not over the follow-up period.
The study also could only observe data up to 2022, after which time, data from Ontario points to decreases in opioid harms in the general population.