The Effects of Social Presence on Adherence-Focused Guidance in Problematic Cannabis Users: Protocol for the CANreduce 2.0 Randomized Controlled Trial

Abstract

BackgroundIn European countries, including Switzerland, cannabis is the most commonly used illicit drug. Offering a Web-based self-help tool could potentially reach users who otherwise would not seek traditional help. However, such Web-based self-help tools often suffer from low adherence.ObjectiveThrough adherence-focused guidance enhancements, the aim of this study was to increase adherence in cannabis users entering a Web-based self-help tool to reduce their cannabis use and, in this way, augment its effectiveness.MethodsThis paper presents the protocol for a three-arm randomized controlled trial (RCT) to compare the effectiveness of (1) an adherence-focused, guidance-enhanced, Web-based self-help intervention with social presence; (2) an adherence-focused, guidance-enhanced, Web-based self-help intervention without social presence; and (3) a treatment-as-usual at reducing cannabis use in problematic users. The two active interventions, each spanning 6 weeks, consist of modules designed to reduce cannabis use and attenuate common mental disorder (CMD) symptoms, including depression, anxiety, and stress-related disorder symptoms based on the approaches of motivational interviewing and cognitive behavioral therapy. With a target sample size of 528, data will be collected at baseline, 6 weeks, and 3 months after baseline. The primary outcome measurement will be the number of days of cannabis use on the preceding 7 days. Secondary outcomes will include the quantity of cannabis used in standardized cannabis joints, the severity of cannabis dependence, changes in CMD symptoms, and adherence to the program. Data analysis will follow the intention-to-treat principle and employ (generalized) linear mixed models.ResultsThe project commenced in August 2016; recruitment is anticipated to end by December 2018. First results are expected to be submitted for publication in summer 2019.ConclusionsThis study will provide detailed insights on if and how the effectiveness of a Web-based self-help intervention aiming to reduce cannabis use in frequent cannabis users can be improved by theory-driven, adherence-focused guidance enhancement.Trial RegistrationInternational Standard Randomized Controlled Trial Number Registry: ISRCTN11086185; http://www.isrctn.com/ISRCTN11086185 (Archived by WebCite at http://www.webcitation.org/6wspbuQ1M)

CANreduce 2.0 Adherence-Focused Guidance for Internet Self-Help Among Cannabis Users: Three-Arm Randomized Controlled Trial

“…The study was approved by the ethics committee of the Canton of Zurich on July 4, 2016 (BASEC 2016-00264) and registered (ISRCTN11086185). A detailed study protocol has been published [ 32 ].…”

CANreduce 2.0: Reduzierung des Cannabiskonsums unter Berücksichtigung von psychischen Komorbiditäten wie der Generalisierten Angststörung – Zwei Fliegen auf einen Schlag?

“…Methods Secondary analysis of cannabis users recruited in the general population in the CANreduce 2.0 study of the 2 active intervention groups (N = 367). For the analyses, these participants were divided into 4 groups according to their achieved General Anxiety Disorder Scale (GAD-7) score: Minimal (GAD-7 score: 0-4; N = 102), mild (5)(6)(7)(8)(9); N = 151), moderate (10)(11)(12)(13)(14); N = 78) and severe (15)(16)(17)(18)(19)(20)(21); N = 36) anxiety disorder. Their treatment courses were compared by Intention-to-treat analyses with regard to their cannabis use and their scores on the Cannabis Use Disorder Identification Test (CUDIT), the Se-verity of Dependence Scale (SDS), the GAD-7, the Center of Epidemiologic Studies of Depression Scale (CES-D) and with regard to their adherence.…”

“…Um einem möglichen Bias durch Drop-Out zu entgegnen [21], kommt die Intention-To-Treat (ITT) Analyse zur Anwendung. Das bedeutet, dass auch Personen, die nicht mehr für eine Nachbefragung verfügbar waren, mit ausgewertet werden.…”

“…StudiendesignDie internetbasierte Selbsthilfeintervention CANreduce 2.0 wurde als eine 3-armige randomisiert kontrollierte Studie (RCT) durchgeführt[21]. Die Studie wurde gemäß der Deklaration von Helsinki, der Europäischen Richtlinie über Medizinprodukte 93/42 / EWG sowie den Anforderungen der ISO-Norm 14155 und ISO 14971 des Schweizer Rechts und der Schweizerischen Aufsichtsbehörde durchgeführt.…”

“…Das detaillierte Studienprotokoll wurde am 31. Januar 2018 veröffentlicht[21]. Nach dem Ausfüllen der Anfangsbefragung (T0) werden die Versuchspersonen randomisiert einer von 2 Versuchsbedingungen oder einer Warteliste zugewiesen.…”