CanCope: Digital Intervention for Coping With Cannabis Craving
Phase: NA
Conditions: Cannabis Use
Sponsor: Trustees of Dartmouth College

CANCOPE MICRORANDOMIZED TRIAL 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
CanCope Micro-Randomized Trial Study Protocol and Statistical Analysis Plan 
NCT05328362 
10/01/2023 
 
 
 

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Methods 
Study Design 
 
The CanCope Study was a micro-randomized trial (MRT) conducted to gather evidence 
about the feasibility of a mobile intervention to reduce cannabis craving among young adults. 
The study duration was from August, 2021 to October, 2021. Each participant remained in the 
study for 29 days including the date of their enrollment.  
Study Participants 
  
Participants were recruited from advertisements on social targeting young adults who 
were interested in reducing their cannabis use and who resided in the United States. Participant 
screening, informed consent, and study surveys were all conducted electronically, with no staff 
contact. Interested individuals from the target population who saw the recruitment ads 
downloaded the MetricWire app by clicking a link (if the participant was already on their phone) 
or by scanning a QR code (if the participant was browsing on their computer). Assessment, 
randomization, and intervention content were delivered through a commercially available app 
(MetricWire). Upon downloading the app, interested individuals were prompted to enter their 
name and email address. After verifying their email address, participants were given a brief 
introduction to the study in the app and asked if they consented to be screened for eligibility to 
participate in the study. Consenting participants continued to complete the initial eligibility 
screening which asked about the participants’ age, whether they were pregnant/breastfeeding, 
whether they were in treatment for substance use, assessed willingness and readiness to reduce 
their cannabis use, and gathered information about participant’s substance use frequency over the 
past 30 days including cannabis use. People were excluded from participating if they were 
outside the ages of 19 – 25 years, pregnant or breastfeeding, currently receiving treatment for 

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substance use, or used cannabis fewer than 10 out of the past 30 days. Eligible participants were 
then given additional information about the study and asked if they consented to participate in 
the intervention phase. Consenting participants who completed the demographics and baseline 
surveys were enrolled. All enrolled participants automatically began the 28-day intervention 
period the day following the completion of their baseline survey. This study was approved by the 
Dartmouth College Institutional Review Board.  
CanCope Intervention 
 
The CanCope intervention was delivered through the MetricWire app, which participants 
downloaded onto their personal mobile phones. CanCope consisted of “push” interventions, 
comprised of messages sent by the MetricWire system. Messages were either a mindfulness-
based strategy for coping with cannabis cravings, a distraction-based strategy for coping with 
cannabis cravings, or a control message thanking the participant for engaging in the study. A 
message was randomly delivered (or not delivered) according to a decision rule. All messages 
were created according to evidence-based interventions (Guarino et al., 2018; Witkiewitz et al., 
2014).  
Example mindfulness-based coping strategy: “You may be thinking ‘I can’t stand this,’ or ‘this is 
unbearable and not worth the effort.’ Just notice these thoughts of distress then carry them away, 
letting them come and go. Remember, you can have whatever thoughts and feelings you have and 
still act differently than what you think or feel.”  
Example distraction-based coping strategy: “We can only pay attention to so many things at one 
time. To distract yourself from unpleasant thoughts, you can pay attention to your physical 
surroundings, or events or objects around you. For example, you might look around the room to 
find all the circular or rectangular objects and count them.” 

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Study Procedure and Randomization 
Baseline 
The screening survey administered at baseline assessed participants’ age, pregnancy or 
breastfeeding status, whether they were receiving counseling or treatment for substance use 
problems, and cannabis use in the past 30 days. Cannabis use in the past 30 days was measured 
using a scale from 0 to 30 days, where 0 = no days of cannabis use in the past 30 days 
(SAMHSA, 2015). If eligible based on the screening survey, participants self-reported gender 
identity, sexual orientation, race, and ethnicity.  
Intervention 
During the intervention, participants received five EMA push notifications via the study 
app daily at a set window to assess their cannabis craving level. Those who self-reported 
elevated cannabis craving (>4 on a scale from 0 – 10 where 0 = no urge to use and 10 = extreme 
urge to use) received a second push notification prompting them to click on a new message. If 
they clicked on that new message, they were eligible for micro-randomization. The new message 
contained either one of the two intervention messages (mindfulness or distraction coping 
strategy) or a control message. Study participants received $1 for each EMA completed, with an 
additional $10 per week if they completed >80% of their EMA prompts for the week.  
 
At each decision point, the randomization was independent of previous randomizations. 
During the 28-day intervention period, messages were randomized up to 140 (5x28) times for 
each participant. We used a probability of .66 for receiving a message and a probability of .34 for 
receiving a control message at each decision point when participants were available for the 
intervention.   
 

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Figure 1. Intervention flow  
 
 
Outcomes and Measures 
 
The aim of this study was to identify which strategies were most effective in helping 
participants cope with their cannabis cravings. 
Proximal Outcome Measure 
 
Cannabis craving has been positively correlated with cannabis use. Therefore, this 
study’s primary proximal, or short-term, outcome was the effect of messaging on cannabis 
craving, determined by assessing the level of craving at the next EMA after the decision point for 
sending a coping strategy or control message. 
Distal Outcome Measure 
 
The distal, or long-term, exploratory outcome was the frequency of cannabis use over the 
past 30 days. The conceptual model underlying this MRT is that if the proposed intervention 
improves participants’ ability to cope with cannabis cravings, they will be less likely to use 
cannabis. Given the exploratory nature of this objective, results are not presented for this 
outcome.  
Statistical Analysis 
We used a centered and weighted least squares (CWLS) method to analyze all available 
data (Boruvka et al., 2018; Klasnja et al., 2019; Qian et al., 2022). This method accommodates 

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within-participant correlation across time which results from the MRT design with decision 
points nested within participants. Furthermore, this method accounts for the endogeneity inherent 
in the MRT design due to the fact participant availability for intervention and covariates (e.g., 
pre-intervention craving level) are likely impacted by prior intervention. By capitalizing on the 
sequential randomization to estimate causal treatment effects, the CWLS method accounts for 
endogeneity in the data analyses (Klasnja et al., 2019; Qian et al., 2020).  
We conducted a power analysis using the MRT sample size calculator to identify the 
needed sample size for 80% power to detect a small effect size of 0.2, assuming a 0.05 type 1 
error rate, and 20% eligibility for randomization (3 out of 5 EMAs completed per day; craving 
level >4 on 1 out of the 3 submitted EMAs; and clicking on the delivered message every time 
craving was elevated). To meet this assumption, the desired sample size was 47. To allow for 
15% attrition defined by failure to complete any EMAs, we recruited 8 additional participants.  
Results 
Study Participants 
 
A total of 93 individuals downloaded the app which housed the intervention (MetricWire; 
www.metricwire.com). Of those, 74 individuals verified their email address used to register for 
the app and were assessed for eligibility to participate in the study. Of the 74 individuals 
assessed, 13 were ineligible because they met exclusion criteria: 4 did not complete the 
screening; 1 did not consent to be screened; 4 were not between the ages of 19 and 25 years; 1 
was pregnant or breastfeeding; 1 was currently in treatment for a substance use disorder; and 3 
did not use cannabis >10 out of the past 30 days. One person met two exclusion criteria and is 
reflected twice in the reason counts. Of the 61 individuals eligible to participate 8 did not enter 
the study: 1 did not complete the consent form; 1 did not consent to participate; 4 did not 

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complete the baseline assessments; and 2 did not complete any EMA. During the course of the 
study, 4 participants were lost to follow-up. We used all available data in the analyses, so all 53 
participants who submitted at least one EMA during the course of the study are included in the 
analyses.  
Outcomes 
Decision Points, Participant Availability, and Message Delivered 
 
For the 53 study participants, there were 140 possible decision points per person during 
the 28 days of the intervention period, for a total of 7420 possible person-decision points among 
all participants. Participants were eligible for the intervention during 1321 of the 7420 decision 
points (18%). A total of 406 mindfulness messages were delivered, 461 distraction messages, 
and 454 control messages when participants were eligible to be randomized to an intervention 
condition. 
Effect of Coping Strategy Messages on Cannabis Craving in the Next EMA after a Decision 
Point 
 
Our primary analysis showed that among all the decision points for which participants 
were eligible to receive an intervention throughout the 28-day intervention period, the average 
craving level after receiving a control message was 4.74 (SD = 2.82) and average craving level 
after receiving an intervention message was 4.63 (SD = 2.78). There was no statistically 
significant intervention effect (z = -0.54, p = .589).  
 
 
 

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