Joint Effort 2.0 : Evaluation Among General Population

" Joint Effort 2.0 " Une Application Mobile de prévention et de réduction Des méfaits: évaluation auprès de Consommateurs de Cannabis

This study aims to evaluate a mobile app designed to promote the safe use of cannabis among adult users in Quebec.

Study Overview

• Status: Recruiting
• Conditions: Cannabis Use
• Intervention / Treatment: Other: Brief normative feedback and standard information; Other: Joint Effort

• Study Type: Interventional
• Enrollment (Estimated): 110
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: José Côté, PhD; Phone Number: 514-890-8000; Email: jose.cote@umontreal.ca

Study Locations

• Canada
  • Quebec
    • Montreal, Quebec, Canada
      • Recruiting
      • Université de Montréal
      • Contact: José Côté; Phone Number: 514-890-8000; Email: jose.cote@umontreal.ca

Participation Criteria

Eligibility Criteria

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

Description

Inclusion Criteria:

• Aged 18 years old or older
• Be an active non-medical cannabis user (ie. self reported past month usage)
• Understand, read and write French
• Own a smartphone (iPhone)

Exclusion Criteria:

• None

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Prevention
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Triple

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Joint Effort; Mobile application	Other: Joint Effort; The Joint Effort intervention is available as an iPhone mobile application in French language. It aims to support cannabis users to take action upon their cannabis use.
Active Comparator: Brief normative feedback and standard information; Webpage	Other: Brief normative feedback and standard information; The brief normative feedback is based on the frequency of cannabis use. Participants will also be offered basic reliable non-personalized information on lower-risk cannabis use in the form of official public websites.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Protective Behavioral Strategies for Marijuana	Adoption of Protective Behavioral Strategies; measured with the Protective Behavioral Strategies for Marijuana scale (PBSM-17). The French version of the questionnaire translated by Côté et al. (2021) will be used. The 17 items each represent a behavioral protection strategy. They are measured in terms of frequency of use on a six-point Likert-type scale (never, rarely, occasionally, sometimes, often and always). The total score of the PBSM-17 is obtained by calculating the total score of each item and then converting this raw score into a standardized form (T-score) ranging from 15 to 73. The lower the total score, the lesser the use of PBS.	Baseline, 2-weeks, 4-weeks

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Intention to take action	Intention to take action on cannabis use is assessed via a three-item French-language questionnaire developed for this study, based on Ajzen's guidelines for measuring Theory of Planned Behavior. The questionnaire consist of 3 items: 1) "I intend to take action on my cannabis use in the coming month"; 2) "In the coming month, the chances that I will take action on my cannabis use are…"; and 3) "In the coming month, I will take action on my cannabis use." The items are rated on a seven-point Likert scale ranging, respectively, from "strongly disagree" to "strongly agree", "very low" to "very high", and "very unlikely" to "very likely". The score of intention to change is the sum of the 3 items (possible score range: 3 to 21). The lower the total score, the weaker the intention to take action on CU.	Baseline, 2-weeks, 4-weeks
Cannabis use frequency	Cannabis use frequency is measured by a question adapted from the French version of the Canadian Community Health Survey (CCHS) : "How often did you use cannabis in the past month?". The answers follows a six-category rating scale: never; one day in the past month; 2-3 days in the past month; 1-2 days per week in the past month; 3-4 days per week in the past month; 5-6 days per week in the past month; and every day.	Baseline, 4-weeks
Severity of Dependence	Level of dependence is measured with the Severity of Dependence Scale (french version). It consists of five items covering different psychological aspects of dependence: feeling of impaired control, anxiety, preoccupations, wish to stop, and compulsive use. The possible score ranges from 0 to 15. Items 1 to 4 are scored as follows: 0 = never/almost never, 1 = sometimes, 2 = often, and 3 = always/nearly always. Item 5 is scored as follows: 0 = not difficult, 1 = quite difficult, 2 = very difficult, and 3 = impossible. Previous studies have set empirically derived optimal cut-off scores for cannabis dependence at 2 to 4 or greater.	Baseline

Other Outcome Measures

Outcome Measure	Measure Description	Time Frame
Engagement	UMARS : engagement subscale The User Version of the Mobile Application Rating Scale (uMARS) is a reliable tool for assessing the quality of mHealth apps. It consists of 20 items grouped into 4 quality subscales-engagement, functionality, aesthetics, and information-as well as 1 subjective quality subscale. Each item is rated on a 5-point scale ranging from 1 (inadequate) to 5 (excellent).	2-weeks post-intervention usage

Collaborators and Investigators

• Sponsor: Centre hospitalier de l'Université de Montréal (CHUM)
• Investigators: Principal Investigator: Didier Jutras-Aswad, Université de Montréal; Principal Investigator: Sylvie Cossette, Université de Montréal; Principal Investigator: Christine Genest, Université de Montréal; Principal Investigator: Shalini Lal, Université de Montréal; Principal Investigator: Judith Lapierre, Laval University; Principal Investigator: Gabrielle Pagé, Université de Montréal; Principal Investigator: Jinghui Cheng, Polytechnique Montréal

Study record dates

Study Major Dates

• Study Start (Actual): April 30, 2026
• Primary Completion (Estimated): April 1, 2027
• Study Completion (Estimated): April 1, 2027

Study Registration Dates

• First Submitted: April 2, 2026
• First Submitted That Met QC Criteria: April 10, 2026
• First Posted (Actual): April 13, 2026

Study Record Updates

• Last Update Posted (Actual): June 3, 2026
• Last Update Submitted That Met QC Criteria: June 1, 2026
• Last Verified: June 1, 2026

More Information

Terms related to this study

• Other Study ID Numbers: 2026-13232

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No