Change in alcohol consumption among French adults participating in Dry January: A 9-month prospective cohort study

BACKGROUND: Temporary alcohol abstinence campaigns, such as Dry January, are increasingly promoted as population-level initiatives to encourage reductions in alcohol consumption, yet evidence on longer-term changes in alcohol consumption following participation remains limited. METHODS: A longitudinal online survey was conducted among French adults participating in Dry January 2024. Participants completed a baseline survey at the end of December and follow-up assessments at 1 month (February), 3 months (April), and 9 months (October). The final cohort included 1,886 participants. Alcohol consumption was measured using the Alcohol Use Disorders Identification Test-Consumption (AUDIT-C) at baseline and at the 3-month and 9-month follow-ups. Changes in AUDIT-C scores were examined using linear mixed-effects models, while logistic regression models were used to identify baseline characteristics associated with reductions in drinking frequency, quantity, and heavy episodic drinking. RESULTS: AUDIT-C scores declined substantially from baseline to 3 months (Cohen's d = 0.68) and remained below baseline at 9 months (d = 0.57) despite a modest rebound, indicating sustained reductions in alcohol consumption. AUDIT-C scores decreased in all drinking risk groups, with larger reductions observed among participants classified as hazardous or harmful drinkers at baseline, compared to low-risk drinkers. Associations between baseline characteristics and alcohol reduction varied across outcomes and follow-up periods. Self-recognition of excessive drinking was the most consistent predictor of reductions across drinking frequency, quantity, and heavy episodic drinking, whereas higher baseline drinking risk was consistently associated with reductions in drinking quantity and heavy episodic drinking, but not drinking frequency. CONCLUSIONS: Participation in Dry January in France was associated with moderate but sustained reductions in alcohol consumption, up to nine months after the campaign. These findings support that temporary abstinence campaigns are a complementary population-level strategy for reducing alcohol-related harm.