Risk factors for alcohol-related injury experienced within a year: results of a nationwide large-scale internet survey.

BACKGROUND

Alcohol-related injuries, including self-injury and harm to others, have multifactorial causes other than alcohol consumption amount and frequency. Here we investigated the determinants of alcohol-related self-injury and harm to others by focusing on the characteristics of alcoholic beverages.

METHODS

We analyzed data from a nationwide internet-based cohort survey conducted in Japan in 2024-2025. Among 11,443 continuous drinkers, alcohol-related self-injury and harm to others within the past year were assessed. Weighted logistic regression models using inverse probability weighting were used to estimate adjusted odds ratios (aORs) and 95% confidence intervals (CIs) with adjustment for demographic, socioeconomic, and clinical characteristics, drinking behaviors, and beverage types.

RESULTS

Of the study population, 285 and 122 participants experienced alcohol-related self-injury and harm to others, respectively. Younger age and frequent heavy episodic drinking showed strong dose-response associations with self-injury and harm to others. Diabetes was associated with increased risk, and depression showed a positive but not consistently statistically significant association. Wine consumption was negatively associated with self-injury (aOR, 0.40; 95% CI, 0.24-0.65; p < 0.001), whereas beer and moderate alcohol-by-volume (4-7%) ready-to-drink beverages were negatively associated with harm to others (beer: aOR, 0.38; 95% CI, 0.15-0.96; p = 0.04; 4-7% chū-hai: aOR, 0.29; 95% CI, 0.13-0.63; p = 0.002).

CONCLUSIONS

Alcohol-related self-injury and harm to others share common and distinct determinants across demographic, clinical, behavioral, and beverage-related factors. These findings suggest that alcohol-related injury risk is primarily driven by drinking pattern and intensity, while beverage-specific associations may provide exploratory insights.