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Trial registered on ANZCTR


Registration number
ACTRN12616000622404p
Ethics application status
Submitted, not yet approved
Date submitted
10/05/2016
Date registered
13/05/2016
Date last updated
13/05/2016
Type of registration
Prospectively registered

Titles & IDs
Public title
A randomised controlled trial of a smartphone application for people wanting to reduce or quit their use of cannabis
Scientific title
A randomised controlled trial of a smartphone application for people wanting to reduce or quit their use of cannabis
Secondary ID [1] 289158 0
None
Universal Trial Number (UTN)
Trial acronym
Linked study record

Health condition
Health condition(s) or problem(s) studied:
Cannabis use 298689 0
Condition category
Condition code
Mental Health 298744 298744 0 0
Addiction

Intervention/exposure
Study type
Interventional
Description of intervention(s) / exposure
We are conducting a randomized controlled study of an app (Joint Control) for cannabis users wishing to reduce/quit their use of cannabis. We are comparing the full app version against a partial app version and a minimal exposure control group.

The full app condition includes 4 main components: screening & feedback, goal setting, coping skills, and self-monitoring. Briefly, the screening & feedback component includes questions about age, sex, recent cannabis use, dependence, and problems. From the answers to these questions, a feedback report is generated that informs the participant about their use relative to population norms, their dependence score, and a list of reported problems. The goal-setting component allows participants to create a change plan, including a date and reduction plan. The coping skills component lists a range of coping skills, both general and specific to reasons for use. The self-monitoring tool allows participants to track their daily use, including amount used, reasons for use, and money spent. Based on this input, tracking information is graphed and summarised for participants to view when they want.

Eligible participants will be sent a link to complete a baseline assessment and after completing this, will be randomised to group. Based on group allocation, participants will be sent a link to one of the three app versions: the full app, the partial app, or the control app, along with download instructions. Participants in the former two groups will be asked to use the app for four weeks (after which time access will be disabled), as much or as little as they choose. Participants' app usage will be monitored to gauge the frequency and duration that each component is accessed across the four week period. The four week period commences the day the link is sent to participants.

After four weeks, all participants will receive an email with a link to complete a post-app assessment. Eight weeks following the baseline assessment, participants will be emailed a link to complete the follow-up assessment. Participants will be reimbursed for completing the post-app and follow-up assessments ($25 each).

Assessments will cover general demographic information, cannabis use and severity of dependence, alcohol and other drug use, psychological distress, treatment history, self-efficacy, and readiness to change.

Intervention code [1] 294684 0
Behaviour
Intervention code [2] 294715 0
Treatment: Other
Comparator / control treatment
The study includes two comparator conditions, a partial app condition and a minimal exposure control condition. Participants in the partial app condition will use a version of the app that includes access to three of the four app components covered in the full app; i.e., the goal setting component, the coping skills component, and the self-monitoring tool (described above). The only component that is excluded from the partial app version is the brief assessment and feedback component. Participants in the partial app condition will have access to the app for four weeks (from the time link is sent), after which time access will be disabled.

In contrast, the control group will be exposed only to a single use, brief assessment and simple feedback only version of the app. This condition involves the single completion of the assessment and provision of feedback (as described above). Access to the app, including the feedback report, is disabled after three days (of link being sent).
Control group
Active

Outcomes
Primary outcome [1] 298226 0
Cannabis use frequency - Number of days in the past month (measured using the Brief Treatment Outcome Measure; BTOM)
Timepoint [1] 298226 0
At baseline, and 4 and 8 weeks following completion of baseline assessment
Primary outcome [2] 298245 0
Cannabis use quantity - Number of joints/cones used typically per day in the past month (converted into standard cannabis units), as measured using the Brief Treatment Outcome Measure (BTOM)
Timepoint [2] 298245 0
At baseline, and 4 and 8 weeks following completion of baseline assessment
Primary outcome [3] 298246 0
Weekly cannabis use (total standard cannabis units per week) - Past 3 months (measured using the Timeline Followback method; TLFB)
Timepoint [3] 298246 0
Eight weeks following completion of baseline assessment
Secondary outcome [1] 323583 0
Past month cannabis dependence (measured using the Severity of Dependence Scale; SDS)
Timepoint [1] 323583 0
At baseline, and 4 and 8 weeks following completion of baseline assessment
Secondary outcome [2] 323584 0
Self-efficacy for resisting the urge to use cannabis (measured using a 20-item self-efficacy scale adapted for cannabis use by Stephens et al, 1995)
Timepoint [2] 323584 0
At baseline, and 4 and 8 weeks following completion of baseline assessment
Secondary outcome [3] 323585 0
Motivation for change, measured using the Readiness to Change Questionnaire (RTCQ)
Timepoint [3] 323585 0
At baseline, and 4 and 8 weeks following completion of baseline assessment
Secondary outcome [4] 323586 0
Psychological distress, measured using the Kessler Psychological Distress Scale (K10)
Timepoint [4] 323586 0
At baseline, and 4 and 8 weeks following completion of baseline assessment

Eligibility
Key inclusion criteria
To be eligible for inclusion in the study, participants will need to be at least 16 years old. They will also need to be English-literate due to the nature of the intervention and assessment methods. Participants will not need to meet the DSM-IV criteria for substance abuse or dependence; rather, they need to have expressed a desire to reduce cannabis use, and have used cannabis within the last month at least weekly.
Minimum age
16 Years
Maximum age
No limit
Gender
Both males and females
Can healthy volunteers participate?
No
Key exclusion criteria
Participants who have received formal treatment for cannabis use within the last three months, or who are currently in treatment for any other substance use problem will be excluded from the study.

Study design
Purpose of the study
Treatment
Allocation to intervention
Randomised controlled trial
Procedure for enrolling a subject and allocating the treatment (allocation concealment procedures)
Methods used to generate the sequence in which subjects will be randomised (sequence generation)
Masking / blinding
Who is / are masked / blinded?



Intervention assignment
Parallel
Other design features
Phase
Not Applicable
Type of endpoint(s)
Efficacy
Statistical methods / analysis
SAMPLE SIZE
Based on a reviews on the effectiveness of online cannabis use treatments in reducing cannabis use, we expected a small to medium effect size. Thus, we calculated that a sample size of n=100 will be needed in the full app group and the control group, each, to have 80% power (alpha=.05) to detect this difference. As we have no reference value to use for the partial app group, we will use the same sample size as for the other two groups (resulting in a total sample size of N=300, i.e., 100 in each group), which will allow for a regression analysis to find a small effect when comparing different active components of the app controlling for baseline use. In anticipation of a drop-out rate of 40% (from a controlled study from a similar population), we aim to recruit a total of 525 participants.

STATISTICAL ANALYSES
The data will primarily be analysed using MANCOVA for cannabis use outcomes (i.e., past month frequency, past month quantity, & dependence). Covariates will include: gender, age, years of use, psychological distress. Additional analyses exploring changes in cannabis use over time will be conducted using GEE. If applicable, multiple imputation analyses will be conducted for missing data.
Linear regressions (or alternative for non-normally distributed data) will be used to examine associations between different components of the app with self-efficacy, readiness to change, and cannabis use outcomes.

Recruitment
Recruitment status
Not yet recruiting
Date of first participant enrolment
Anticipated
Actual
Date of last participant enrolment
Anticipated
Actual
Date of last data collection
Anticipated
Actual
Sample size
Target
Accrual to date
Final
Recruitment in Australia
Recruitment state(s)
ACT,NSW,NT,QLD,SA,TAS,WA,VIC

Funding & Sponsors
Funding source category [1] 293557 0
Government body
Name [1] 293557 0
Department of Health
Address [1] 293557 0
Department of Health
GPO Box 9848,
Canberra ACT 2601, Australia
Country [1] 293557 0
Australia
Primary sponsor type
University
Name
National Cannabis Prevention and Information Centre, UNSW
Address
UNSW Randwick Campus NDARC
Building R1 Level 1, 22-32 King St
Randwick NSW 2031Australia
Country
Australia
Secondary sponsor category [1] 292375 0
None
Name [1] 292375 0
Address [1] 292375 0
Country [1] 292375 0

Ethics approval
Ethics application status
Submitted, not yet approved
Ethics committee name [1] 294992 0
UNSW Human Research Ethics Committee
Ethics committee address [1] 294992 0
UNSW Research Ethics & Compliance Support
The University of New South Wales
Sydney NSW 2052 Australia
Ethics committee country [1] 294992 0
Australia
Date submitted for ethics approval [1] 294992 0
27/04/2016
Approval date [1] 294992 0
Ethics approval number [1] 294992 0

Summary
Brief summary
The study is a randomised controlled trial of an app for cannabis users wishing to reduce/quit their use of cannabis. Specifically, the study involves a randomised controlled trial of three app versions to determine the effectiveness of the app, and its various active components, in helping cannabis users reduce their use.
Trial website
Trial related presentations / publications
Public notes

Contacts
Principal investigator
Name 65686 0
Prof Jan Copeland
Address 65686 0
Building R1 (Randwick Campus)
NDARC UNSW, SYDNEY NSW, 2052
Country 65686 0
Australia
Phone 65686 0
+61 2 93850231
Fax 65686 0
Email 65686 0
j.copeland@unsw.edu.au
Contact person for public queries
Name 65687 0
Ms Lisa Gibson
Address 65687 0
Building R1 (Randwick Campus)
NDARC UNSW, SYDNEY NSW, 2052
Country 65687 0
Australia
Phone 65687 0
+61 2 89361197
Fax 65687 0
Email 65687 0
lisa.gibson@unsw.edu.au
Contact person for scientific queries
Name 65688 0
Dr Peter Gates
Address 65688 0
Building R1 (Randwick Campus)
NDARC UNSW, SYDNEY NSW, 2052
Country 65688 0
Australia
Phone 65688 0
+61 2 93850269
Fax 65688 0
Email 65688 0
p.gates@unsw.edu.au

No information has been provided regarding IPD availability
Summary results
No Results