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Study protocol for a single-blind, randomised controlled, non-inferiority trial of internet-based versus face-to-face cognitive behaviour therapy for obsessive–compulsive disorder
  1. Christian Rück1,2,
  2. Lina Lundström1,2,
  3. Oskar Flygare1,
  4. Jesper Enander1,2,
  5. Matteo Bottai3,
  6. David Mataix-Cols1,2,
  7. Erik Andersson1
  1. 1 Centre for Psychiatry Research, Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden
  2. 2 Stockholm Health Care Services, Stockholm, Sweden
  3. 3 Institute of Environmental Medicine, Biostatistics, Karolinska Institutet, Stockholm, Sweden
  1. Correspondence to Dr Christian Rück; christian.ruck{at}


Introduction Expert guidelines recommend cognitive–behavioural therapy (CBT) as a first-line treatment for obsessive–compulsive disorder (OCD), but the majority of patients with OCD do not have access to CBT. Internet-delivered CBT (ICBT) has the potential to make this evidence-based treatment more accessible while requiring less therapist time than traditional face-to-face (f2f) CBT. Data from six clinical trials suggest that ICBT for OCD is both efficacious and cost-effective, but whether ICBT is non-inferior to traditional f2f CBT for OCD is yet unknown.

Methods and analysis A single-blind, randomised, controlled, non-inferiority trial comparing therapist-guided ICBT, unguided ICBT and individual (f2f) CBT for adult OCD patients. The primary objective is to investigate whether ICBT is non-inferior to gold standard f2f CBT. Secondary objectives are to investigate if ICBT is equally effective when delivered unguided, to establish the cost-effectiveness of ICBT and to investigate if the treatment outcome differs between self-referred and clinically referred patients. Participants will be recruited at two specialist OCD clinics in Stockholm and also through online self-referral. Participants will be randomised to one of three treatment conditions: F2f CBT, ICBT with therapist support or unguided ICBT. The total number of participants will be 120, and masked assessments will be administered at baseline, biweekly during treatment, at post-treatment and at 3-month and 12-month follow-ups. The main outcome measure is the clinician-rated Yale-Brown Obsessive Compulsive Scale (Y-BOCS) at 3-month follow-up. The margin of non-inferiority is set to 3 points on the Y-BOCS using a 90% CI.

Ethics and dissemination The study has been approved by the Regional Ethics Board of Stockholm (REPN 2015/1099-31/2) and registered at (NCT02541968). The study will be reported in accordance with the Consolidated Standards of Reporting Trials statement for non-pharmacological trials. The results will be published in peer-reviewed academic journals and disseminated to patient organisations and media.

Trial registration number NCT02541968; Pre-results.

  • obsessive compulsive disorder
  • internet delivered cognitive behaviour theraphy
  • non-inferiority study
  • clinical randomized controlled trial
  • adult psychiatry

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  • Contributors CR and LL wrote the first draft of the paper. All authors conceived the study and revised the manuscript for relevant scientific content. MB specifically revised the statistical analyses and power calculation sections of the paper. All authors approved the final version of the manuscript.

  • Funding This study is funded by the Swedish Research Council (K2013-61P-22168) and the regional agreement on medical training and clinical research (ALF) between Stockholm County Council and Karolinska Institutet.

  • Competing interests None declared.

  • Patient consent Not requried.

  • Ethics approval The study has been approved by the Regional Ethics Board of Stockholm (REPN 2015/1099-31/2) and registered at (NCT02541968).

  • Provenance and peer review Not commissioned; externally peer reviewed.

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