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.

Study Overview

• Status: Completed
• Conditions: Intention; Knowledge; Behaviour Change; Risk Perception; Support for Alcohol Policies; Emotional Response; Product Appeal
• Intervention / Treatment: Other: No outcome pre-testing; Other: Outcome pre-testing; Behavioral: Responsibility message on alcohol label; Behavioral: Front label; Behavioral: Back label; Behavioral: Alcohol health warning label - cancer

• Study Type: Interventional
• Enrollment (Actual): 1410
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Spain
  • Barcelona, Spain
    • Sampled supermarkets in selected city neighbourhoods

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: Yes

Description

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

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Prevention
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: None (Open Label)

Number of Arms

8

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Active Comparator: Responsibility message - front of the container / no pre-test; A sticker with a message to drink responsibly is applied to the front of the container. There is no question on knowledge of alcohol related harms at baseline.	Other: No outcome pre-testing; Primary outcome (knowledge of alcohol related harms) is not tested at baseline.; Behavioral: Responsibility message on alcohol label; A sticker with a message to drink responsibly will be applied to alcoholic beverage containers purchased by the participants.; Behavioral: Front label; A sticker will be applied to the front of the alcoholic beverage containers purchased by the participants.
Active Comparator: Responsibility message - back of the container / no pre-test; A sticker with a message to drink responsibly is applied to the back of the container. There is no question on knowledge of alcohol related harms at baseline.	Other: No outcome pre-testing; Primary outcome (knowledge of alcohol related harms) is not tested at baseline.; Behavioral: Responsibility message on alcohol label; A sticker with a message to drink responsibly will be applied to alcoholic beverage containers purchased by the participants.; Behavioral: Back label; A sticker will be applied to the back of the alcoholic beverage containers purchased by the participants.
Experimental: Cancer message - front of the container / no pre-test; A sticker with a message on alcohol causing cancer is applied to the front of the container. There is no question on knowledge of alcohol related harms at baseline.	Other: No outcome pre-testing; Primary outcome (knowledge of alcohol related harms) is not tested at baseline.; Behavioral: Front label; A sticker will be applied to the front of the alcoholic beverage containers purchased by the participants.; Behavioral: Alcohol health warning label - cancer; A sticker with health information on alcohol causing cancer is applied to alcoholic beverage containers purchased by the participants.
Experimental: Cancer message - back of the container / no pre-test; A sticker with a message on alcohol causing cancer is applied to the back of the container. There is no question on knowledge of alcohol related harms at baseline.	Other: No outcome pre-testing; Primary outcome (knowledge of alcohol related harms) is not tested at baseline.; Behavioral: Back label; A sticker will be applied to the back of the alcoholic beverage containers purchased by the participants.; Behavioral: Alcohol health warning label - cancer; A sticker with health information on alcohol causing cancer is applied to alcoholic beverage containers purchased by the participants.
Active Comparator: Responsibility message - front of the container / pre-test; A sticker with a message to drink responsibly is applied to the front of the container. There is a question on knowledge of alcohol related harms at baseline.	Other: Outcome pre-testing; Primary outcome (knowledge of alcohol related harms) is tested at baseline.; Behavioral: Responsibility message on alcohol label; A sticker with a message to drink responsibly will be applied to alcoholic beverage containers purchased by the participants.; Behavioral: Front label; A sticker will be applied to the front of the alcoholic beverage containers purchased by the participants.
Active Comparator: Responsibility message - back of the container / pre-test; A sticker with a message to drink responsibly is applied to the back of the container. There is a question on knowledge of alcohol related harms at baseline.	Other: Outcome pre-testing; Primary outcome (knowledge of alcohol related harms) is tested at baseline.; Behavioral: Responsibility message on alcohol label; A sticker with a message to drink responsibly will be applied to alcoholic beverage containers purchased by the participants.; Behavioral: Back label; A sticker will be applied to the back of the alcoholic beverage containers purchased by the participants.
Experimental: Cancer message - front of the container / pre-test; A sticker with a message on alcohol causing cancer is applied to the front of the container. There is a question on knowledge of alcohol related harms at baseline.	Other: Outcome pre-testing; Primary outcome (knowledge of alcohol related harms) is tested at baseline.; Behavioral: Front label; A sticker will be applied to the front of the alcoholic beverage containers purchased by the participants.; Behavioral: Alcohol health warning label - cancer; A sticker with health information on alcohol causing cancer is applied to alcoholic beverage containers purchased by the participants.
Experimental: Cancer message - back of the container / pre-test; A sticker with a message on alcohol causing cancer is applied to the back of the container. There is a question on knowledge of alcohol related harms at baseline.	Other: Outcome pre-testing; Primary outcome (knowledge of alcohol related harms) is tested at baseline.; Behavioral: Back label; A sticker will be applied to the back of the alcoholic beverage containers purchased by the participants.; Behavioral: Alcohol health warning label - cancer; A sticker with health information on alcohol causing cancer is applied to alcoholic beverage containers purchased by the participants.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Knowledge of alcohol causing cancer	Knowledge will be assessed with the question "Which of the following diseases and conditions does alcohol consumption increase the risk of? (select all that apply)", with the possible choices being "Cancer", "Heart disease", "Respiratory disease", "Alcohol Use Disorder", "Injuries", "Diabetes" and "Liver disease" displayed randomly, and "I don't know" and "None" as exclusive options. If participants select "Cancer" as an outcome, a follow up question will ask: "Which of the following cancers do you think drinking alcohol increases the risk of? (select all that apply)", with "Female breast cancer", "Liver cancer", "Colon cancer", "Skin cancer", "Oral cancer", displayed randomly, and "I don't know" and "None" as exclusive options. The outcome will be dichotomous based on whether the participants correctly identify the link between alcohol and two cancers mentioned in the label: breast and colon cancer.	1 week / 1 month

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Alcohol consumption behaviour	Decrease in alcohol consumption will be measured with measuring the amount of standard drinks consumed in the last 7 days ("How many standard drinks of alcohol did you drink over the last 7 days?"), as well as based on question on whether they have foregone an alcoholic drink because they wanted to drink less (In the last 7 days, did you ever forego an alcoholic drink because you wanted to drink less? Yes/No).	1 week / 1 month
Risk perception	Perceived personal cancer risk will be measured with question "If I consume alcohol on a regular basis, I am at greater risk of getting cancer." Perceived general health risk will be measured with question "If I consume more alcohol, I am at greater risk for health harm". Both questions will be measured on 5-point Likert scale (strongly Disagree to Strongly Agree).	1 week / 1 month
Behavioural intention	Behavioural intention to decrease alcohol consumption will be measured with the question "I intend to cut down on the number of alcohol units that I drink in the forthcoming month" on 5-point Likert scale (Strongly Disagree to Strongly Agree), only at both follow-ups.	1 week / 1 month
Emotional response to the labels	Emotional response to the labels will only be measured among those reporting to have noticed the labels: "Thinking about the labels on the alcohol containers I've seen as part of this study, I felt: disgusted / afraid / uncomfortable / worried" / excited / pleased" With Likert answers scale from 1 to 5 (1 = "not at all", 3 = "moderately", and 5 = "very").	1 week
Support for alcohol policies	Support for alcohol policies will be measured with listing range of alcohol policies (e.g. increasing the price of alcohol, reducing the number of outlets that sell alcohol" and asking the participants "To what extent would you support the government in your country introducing the following alcohol-related policies? Please indicate your answer on the scale below from 1 (strongly disagree) to 5 (strongly agree).	1 week / 1 month
Product appeal	It will only be measured among those reporting to have noticed the labels, with three items developed for this study ("I found the beverages less appealing after noticing the health information on the labels"; "The health information on the labels reduced my enjoyment of these beverages"; "I felt the health information on the label detracted from the overall alcohol product appearance") on 5-point Likert scale (Strongly Disagree to Strongly Agree).	1 week

Collaborators and Investigators

• Sponsor: World Health Organization
• Collaborators: IPSOS; Program on Substance Abuse, Public Health Agency, Government of Catalonia
• Investigators: Principal Investigator: Dasa Kokole, PhD, World Health Organisation Regional Office for Europe

Study record dates

Study Major Dates

• Study Start (Actual): April 23, 2025
• Primary Completion (Actual): July 25, 2025
• Study Completion (Actual): July 25, 2025

Study Registration Dates

• First Submitted: April 1, 2025
• First Submitted That Met QC Criteria: April 1, 2025
• First Posted (Actual): April 8, 2025

Study Record Updates

• Last Update Posted (Actual): August 6, 2025
• Last Update Submitted That Met QC Criteria: July 31, 2025
• Last Verified: July 1, 2025

More Information

Terms related to this study

• Keywords: alcohol; health warning label; supermarket
• Additional Relevant MeSH Terms: Anti-Infective Agents; Physiological Effects of Drugs; Central Nervous System Depressants; Anti-Infective Agents, Local; Ethanol
• Other Study ID Numbers: ERC.0004213; 24/228-P (Other Identifier: Ethical Committee for Research with Medicines (CEIm) IDIAP Jordi Gol)

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: YES
• IPD Plan Description: All IPD that underlie results in a publication(s).
• IPD Sharing Time Frame: The dataset will be available following the open data sharing practices, and will be available on Figshare repository (https://figshare.com/) once the article with the main results is published.
• IPD Sharing Access Criteria: The interested researchers will be able to access and download the data directly through the platform, without requiring any permissions. The article, including the dataset will be shared under a noncommercial license (e.g. Creative Commons Attribution-NonCommercial (CC BY-NC)), allowing others to use the data for research, educational, or other noncommercial purposes, but not for commercial advantage or monetary gain.
• IPD Sharing Supporting Information Type: STUDY_PROTOCOL; SAP; ANALYTIC_CODE

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No
• product manufactured in and exported from the U.S.: No