Clinical trial NCT05836207: Rewards for Cannabis Abstinence-study
Official title: The Cost-effectiveness of Contingency Management Compared to Standard Cognitive Behavioral Treatment for Treating Cannabis Use Disorder in Youth: A Randomized Controlled Trial
Study type: INTERVENTIONAL
Overall status: RECRUITING
Phase: NA
Conditions: Cannabis Use Disorder
Keywords: contingency management
cognitive behavioural therapy
CM
CBT
cost-effectiveness
youth
randomized controlled trial (RCT)
Lead sponsor: Parnassia Addiction Research Centre
Sponsor class: OTHER
Collaborators: name: Leiden University Medical Center
name: Brijder Verslavingszorg
name: Antes
name: Novadic-Kentron
name: Amsterdam University of Applied Sciences
name: Academisch Medisch Centrum - Universiteit van Amsterdam (AMC-UvA)
name: Trimbos
name: Het Zwarte Gat
First posted: 2023-05-01
Enrollment: 154
Sex: ALL
Minimum age (years): 16
Maximum age (years): 22
Standard ages: CHILD
ADULT
Accepts healthy volunteers: no
Allocation: RANDOMIZED
Intervention model: PARALLEL
Primary purpose: TREATMENT

Brief summary: The goal of this clinical trial is to investigate the (cost-)effectiveness of contingency management (CM) compared with Cognitive Behavioural Therapy (CBT) for the treatment of cannabis use disorder (CUD) in youth (16-22 years).

The main questions it aims to answer are:

* What is the efficacy of 12 weeks outpatient CM versus CBT in youths with a CUD, in terms of cannabis abstinence during the intervention period?
* What is the long-term efficacy of CM versus CBT at 6- and 12-months follow-up (FU)?
* What is the cost-effectiveness of CM versus CBT at 12-months FU from a societal perspective?

Study hypotheses are:

1. CM will result in more cannabis-abstinent days than CBT during the intervention; 2. CM is more effective and cost-effective than CBT at 12 months follow-up.

Eligible patients (n=154) will be randomly assigned to either 12 weeks of outpatient CM or CBT. Assessments are conducted by trained research-assistants at baseline, after 6, 12, 26 and 52 weeks, and twice-weekly during treatment and consist of questionnaires, a computer task and collection of urine samples. Primary endpoint is the number of biochemically verified cannabis abstinent days in the 12-week treatment period. Key secondary endpoint: Treatment response: 50% or more reduction in cannabis use days in the past 4 weeks, compared with baseline.

The primary outcome will be modelled in the intention-to-treat population in a (negative binomial) regression analysis with treatment group as independent variable and stratification variables as covariates.

Cost-effectiveness and cost-utility analysis (CEA; CUA) will be performed from a societal perspective. CEA: Treatment response is the central clinical endpoint for calculations of incremental costs per responder. CUA: Incremental costs per QALY (based on EuroQoL).


Eligibility criteria: Inclusion Criteria:

* Youths (16-22 years) seeking treatment for a primary CUD
* Regular cannabis use (≥14 days) in past 4 weeks
* Intention to cease cannabis use during intervention
* Able and willing to attend the treatment center and submit urine samples under supervision twice-weekly
* Informed consent.

Exclusion Criteria:

* Health contra-indications (e.g., acute psychosis/suicidality)
* Insufficient Dutch language.

Primary outcomes:
measure: Cannabis-abstinent days (biochemically verified)
timeFrame: 12 weeks
Secondary outcomes:
measure: long-term 'treatment response'
timeFrame: 52 weeks
measure: Incremental costs per treatment responder
timeFrame: 52 weeks
measure: Incremental costs per QALY
timeFrame: 52 weeks
Other outcomes:
Locations:
city: Rotterdam
country: Netherlands
facility: Antes Youz
city: the Hague
country: Netherlands
facility: Brijder
city: Vught
country: Netherlands
facility: Novadic-Kentron
Study officials:
affiliation: PARC
name: Renske Spijkerman, PhD
role: PRINCIPAL_INVESTIGATOR
affiliation: PARC
name: Vincent Hendriks, Prof. dr.
role: STUDY_DIRECTOR
References: