Personalized Feedback Intervention to Reduce Risky Cannabis Use.

Study Overview
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Brief Summary
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The purpose of this project is to determine whether participants who receive a personalized feedback report and educational materials about risky cannabis use will be less likely to report risky cannabis use at follow-up compared to participants who only received educational materials.

Detailed Description
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This project aims to reduce risky cannabis use among those with less severe cannabis use, most of whom will never seek formal treatment. All of the participants will receive educational material regarding risky cannabis use and its prevention. Half of the participants will also be assigned by chance to receive a personalized feedback report. The investigators hypothesize that: Participants who receive the full personalized feedback intervention will be less likely to report risky cannabis use at 3- and 6-month follow-ups compared to participants who receive educational materials only (Primary Hypothesis). Participants who receive the full personalized feedback intervention will report greater reductions in their perceptions of how much others use cannabis at a 3-month follow-up compared to participants who receive educational materials only. Reductions in perceptions of how much others use cannabis at 3-month follow-up will be positively associated with reduction in the participant's risky cannabis use at 6-month follow-up. A 2-arm parallel group randomized controlled trial will be conducted to test these hypotheses with follow-ups occurring at 3 and 6 months after randomization. Online media advertisements will be used to recruit people currently using cannabis. The advertisements will be placed across Canada using locations found successful in previous trials to rapidly recruit participants (e.g. Google AdWords).

Official Title
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Personalized Feedback Intervention to Reduce Risky Cannabis Use: Randomized Controlled Trial

Conditions
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Cannabis Use

Intervention / Treatment
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* Behavioral: Personalized Feedback
* Behavioral: Education


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Score of 4 or more on the Alcohol, Smoking, and Substance Involvement Screening Test, Cannabis subscale (ASSIST) Exclusion Criteria: Being under 18 years of age

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 99 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Personalized Feedback and Education<br>This arm is provided personalized feedback concerning their cannabis use in addition to educational materials about risky cannabis use. | Behavioral: Personalized Feedback<br>* A report comparing the participant's cannabis use to peer usage, and summarizing problems experienced and risk associated with future use.<br>Behavioral: Education<br>* Canada's Lower-Risk Cannabis Use Guidelines prepared by the Centre for Addiction and Mental Health which outlines methods to help reduce health risks associated with cannabis use.<br>|
| Active Comparator: Education<br>This arm is provided educational materials about risky cannabis use. | Behavioral: Education<br>* Canada's Lower-Risk Cannabis Use Guidelines prepared by the Centre for Addiction and Mental Health which outlines methods to help reduce health risks associated with cannabis use.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Cannabis Use in the last 30 days | Change in the number of days participant used cannabis in the past 30-days from baseline | 3 and 6 months | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Alcohol, Smoking, and Substance Involvement Screening Test (ASSIST, cannabis subscale) | Change in cannabis subscale scores from baseline. Scores are calculated as a sum of six items and totals can range from 0 to 39 with higher scores indicating greater risk. | Baseline, 3 and 6 months | 
| Perceptions of Cannabis Use by Peers in the past 3 months | Change in participant's perceptions of how much their peers (same age and gender) use cannabis. Measured as a percentage of peers that do not use cannabis (%) and a 5-points Likert scale, 0 Never to 5 Daily or Almost daily of frequency of peer use | Baseline, 3 months |