Development and Testing of the Effects of a Digital Intervention for Reducing Cannabis-Related Risks
Summary description of the study
Even though many people consume cannabis and numerous states are legislating to regulate its sale, cannabis consumption is associated with various health risks. As part of a pilot trial for the sale of recreational cannabis, we developed a prevention intervention aimed at promoting risk reduction. Different modules were developed and pre-tested by small groups from the target population. Feedback from the target population helped improve the intervention and produce a prototype that will be tested in this study. The objective of the study is to test the effects of the developed intervention on 565 adult cannabis consumers participating in the pilot trial for the sale of cannabis in Lausanne. The different modules of the intervention will be offered or not to participants randomly. This will allow us to compare the effects of the different modules on the consumption behavior of participants who will complete a follow-up questionnaire 1 month and 7 months after gaining access to the intervention.
(BASEC)
Intervention under investigation
Digital intervention (web application) promoting the reduction of cannabis-related risks
(BASEC)
Disease under investigation
Reduction of risks related to recreational cannabis consumption
(BASEC)
Adult cannabis consumers (18+) residing in the city of Lausanne, included in the pilot trial for the sale of recreational cannabis Cann-L and agreeing to share their follow-up data. (BASEC)
Exclusion criteria
Pregnant and breastfeeding individuals, minors, individuals with a health issue for which cannabis consumption is contraindicated (e.g., severe psychiatric disorders). (BASEC)
Trial sites
Lausanne
(BASEC)
Sponsor
Centre hospitalier universitaire vaudois (CHUV)
(BASEC)
Contact
Contact Person Switzerland
Jacques Gaume
+41213144105
jacques.gaume@clutterchuv.chCentre hospitalier universitaire vaudois (CHUV) - Service de médecine des addictions
(BASEC)
General Information
University of Lausanne Hospitals
+41 21 314 41 05+41 21 314 41 05
jacques.gaume@clutterchuv.chjacques.gaume@clutterchuv.ch(ICTRP)
General Information
University of Lausanne Hospitals
(ICTRP)
Name of the authorising ethics committee (for multicentre studies, only the lead committee)
Ethics Committee Vaud
(BASEC)
Date of authorisation
10.11.2025
(BASEC)
ICTRP Trial ID
NCT07157540 (ICTRP)
Official title (approved by ethics committee)
Testing the Effects of a Digital Intervention for Cannabis Harm Reduction – The Cann’App fractional factorial randomized controlled trial (BASEC)
Academic title
Testing the Effects of a Digital Intervention for Cannabis Harm Reduction - The Cann'App Fractional Factorial Randomized Controlled Trial (ICTRP)
Public title
Testing the Effects of Cann'App, a Digital Intervention for Cannabis Harm Reduction (ICTRP)
Disease under investigation
Cannabis UseHarm Reduction (ICTRP)
Intervention under investigation
Behavioral: Personalized Feedback on Cannabis Protective Behavioral Strategies, Cannabis Use, Cannabis Expenditures, and Cannabis-Related Consequences (PF)Behavioral: Imagining the Future Using Counterfactual Thinking and Episodic Future Thinking (IMAGIN)Behavioral: Behavioral Economics-Informed Exercises to Increase Motivation to Engage in Substance-Free Activities (SFAS)Behavioral: Information (ICTRP)
Type of trial
Interventional (ICTRP)
Trial design
Allocation: Randomized. Intervention model: Factorial Assignment. Primary purpose: Prevention. Masking: Triple (Participant, Investigator, Outcomes Assessor). (ICTRP)
Inclusion/Exclusion criteria
Inclusion Criteria:
- Eligible participants will be those included in the pilot trial of cannabis sales
regulation in Lausanne, Switzerland (Cann-L study).
Inclusion criteria in Cann-L study are:
- being adult (>18 years old),
- having current cannabis use (i.e., use at least once a month over the last 6 months)
- living in the city of Lausanne. To enter the study, they complete an entry
assessment verifying their age and proof of residence, and confirming that they have
current cannabis use.
Exclusion Criteria:
- Cann-L exclusion criteria comprise:
- being younger than 18 years old,
- being pregnant or breastfeeding,
- having a health condition contraindicating the use of cannabis (e.g., severe
psychiatric disorder).
The consent to participate in the Cann-L parent trial comprises an option to be contacted
to participate in sub-studies, including studies on prevention measures. All participants
having accepted to be so contacted will be proposed to participate in the present study.
Therefore, additional exclusion criteria for the present study include:
- not providing informed consent to participate in sub-studies, including studies on
prevention measures,
- not providing informed consent to participate in the present study. (ICTRP)
not available
Primary and secondary end points
Frequency of Protective Behavioral Strategies for Marijuana Use as Measured by the PBSM-17 Short Form Scale (ICTRP)
Cannabis Use Frequency;Number of Hours High on a Typical Day (ICTRP)
Registration date
not available
Incorporation of the first participant
not available
Secondary sponsors
Swiss National Science Foundation;Apptitude;Addiction Switzerland (ICTRP)
Additional contacts
Jacques Gaume, PhDJacques Gaume, PhDJacques Gaume, PhD, jacques.gaume@chuv.chjacques.gaume@chuv.ch, +41 21 314 41 05+41 21 314 41 05, University of Lausanne Hospitals (ICTRP)
Secondary trial IDs
10001E_220072, 2025-00428 (ICTRP)
Results-Individual Participant Data (IPD)
not available
Further information on the trial
https://clinicaltrials.gov/study/NCT07157540 (ICTRP)
Results of the trial
Results summary
not available
Link to the results in the primary register
not available