Exploring the Dose-Response Relationship Between Alcohol Consumption and Harm to Others in Australia

Alcohol consumption often leads to harm to individuals other than the drinker. Yet, few studies have quantified an exposure-response gradient using "nominated" drinkers' alcohol volume and their heavy episodic drinking (HED) frequency to predict harm-type burden and overall severity among people harmed by someone else's alcohol use. We examined these dose-response relationships across sociodemographic groups.

Data were drawn from the cross-sectional Australian 2021 Alcohol's Harm to Others (AHTO) Survey. A total of 2574 adults (18+ years) participated, of whom 554 reported harm from another person's drinking in the past 12 months. Respondents identified the person who harmed them the most (the "nominated drinker") and reported on the person's weekly alcohol volume and frequency of HED. Harms experienced included an overall harm score (0-10 scale) and a count of 14 specific harms.

There was a significant positive dose-response relationship between the nominated drinker's alcohol consumption (both weekly volume and frequency of HED) and the degree of harm experienced by respondents. Although subgroup analyses suggested stronger effects among women, younger respondents, and when the drinker was a (former) partner, these differences were not statistically significant.

Greater alcohol consumption and more frequent HED are associated with more severe harms to others, regardless of respondents' sociodemographic background. A clear dose-response relationship exists between alcohol consumption by a known drinker and harm to others. The dose-response gradient was stronger at higher exposure levels, suggesting that reducing very frequent heavy drinking may yield disproportionately larger reductions in AHTO burden.