The increase in risk classification using Canada's Guidance on Alcohol and Health: an empirical examination in a sample of community adults in Ontario.

Introduction: The 2023 Canadian Centre on Substance Use and Addiction drinking guidelines specify a universal low-risk threshold of 2 or fewer drinks per week, lower than previous guidelines that recommended no more than 10 drinks per week or 2 per occasion for females, and 15 per week or 3 per occasion for males. This study examined the increases in risk classification and perceptions of these new guideline thresholds.

Methods: Prevalence of those exceeding the new low-risk threshold was compared with that of previous and other international guidelines in an observational cohort of community adults (N = 1502) from southern Ontario who had been followed since 2018 (11 waves of data collection). To examine awareness of the new guidelines and perceived risk of drinking beyond them, a follow-up was conducted with a subset of the cohort, three months after the release of the guidelines (April 2023).

Results: Across waves, on average, 52% exceeded the new low-risk threshold compared to 11% who exceeded previous guidelines. Other international guidelines classified, on average, 16% (US), 20% (UK) and 29% (WHO) of the sample as exceeding low-risk guidelines. Approximately half of study participants (51%) were aware of Canada's new guidelines, but 77% perceived exceeding 2 drinks per week as having little to no risk.

Conclusion: Over four times more adults exceeded the new low-risk drinking threshold compared to that of the previous Canadian guidelines. Additionally, more were classified as exceeding the new low-risk threshold compared to other international drinking thresholds. These results, combined with low perceptions of risk associated with consuming more than 2 drinks per week, suggest that many Canadians are at risk of exceeding the new guidelines.