Impact of Alcohol Labels in a Real-World Setting

Impact of Providing Health Information on Alcohol Labels in a Real-World Setting: a Randomized Controlled Trial Among Supermarket Customers in Barcelona

The goal of this randomized controlled trial is to evaluate the impact of health information labeling on alcohol-related knowledge and behaviors in adults purchasing alcohol in Barcelona, Spain. The main questions it aims to answer are:

• Does a label containing a cancer message have a larger impact on knowledge, behavior, intentions, risk perception, emotional response, product appeal and policy support compared to a responsibility label?
• Does the positioning of the label (front vs. back) on the alcohol container affect these outcomes?

Researchers will compare the impact of cancer message labels vs. responsibility labels and front vs. back positioning to see if there are differences in the primary outcome (knowledge of alcohol causing cancer) and secondary outcomes (behavior, intentions, risk perception, emotional response, and policy support).

Additionally, the study will provide insight in whether there is a testing effect of primary outcome pre-measurement by exposing only half of the sample to baseline question on knowledge of alcohol related harms.

Participants will:

• Be recruited in front of selected supermarkets in Barcelona after purchasing alcohol for their own consumption.
• Complete a baseline questionnaire.
• Receive a sticker containing a randomly assigned health message that will be applied to every alcohol beverage they have purchased.
• Receive an invitation to complete two follow-up surveys, one a week and one a month after the intervention.

Inclusion Criteria:

• have just purchased at least one alcoholic beverage container for their own consumption
• speak Spanish or Catalan
• are 18 years or older
• provide informed consent to participation

Exclusion Criteria:

- all the purchased alcohol containers are too small for a label sticker to be affixed