ICBT for OCD in Children With Autism

Primary objective: To determine the clinical efficacy of autism-adapted internet-delivered exposure with response prevention (I-ERP) in reducing OCD symptom severity (as measured by the Children's Yale Brown-Obsessive Compulsive Scale; CY-BOCS) in children and adolescents with OCD and autism spectrum disorder (ASD), compared with an active control intervention of high ecological validity (internet-delivered stress management; I-SM).

Secondary objectives:

1. To establish the 6-month durability of the treatment effects in a naturalistic follow-up. 2. To conduct a health economic evaluation of I-ERP, compared with I-SM, at the primary endpoint (3-month follow-up) from the health organisation payer, health care sector, and societal perspectives. 3. To conduct a process evaluation with a subset of participants allocated to the I-ERP arm, focusing on implementation, mechanisms of impact, and context.

Type of trial: A multisite parallel-group randomised controlled superiority trial, with embedded health economic and process evaluation.

Rationale: OCD and ASD are two frequently co-occuring disorders, associated with significant impairments in daily life. Cognitive-behavioural therapy (CBT) specifically adapted to ASD is a promising treatment for this patient group, but further research is needed to fully establish its efficacy. Furthermore, ASD-adapted CBT for OCD is a highly specialised treatment, not accessible for most patients. Offering treatment in a digital format could dramatically increase treatment availability for these children.

Planned trial sites: The study will be coordinated from the Department of Clinical Neuroscience at Karolinska Institutet (the Sponsor). There will be three collaborating study sites: BUP OCD och relaterade tillstånd (Region Stockholm), BUP Specialmottagning (Västra Götalandsregionen), and BUP Skåne (Region Skåne). Each of the three sites will assess and treat participants from their own region, and occasionally from adjacent regions.

Trial design and methods: All potential participants are initially screened via the telephone or at one of the three participating centres. If screening is positive, an inclusion assessment will follow. Individuals who are eligible and have consented to participate in the trial will be randomised to one of two trial arms. In one arm, participants will receive 12 modules of therapist- and parent-guided I-ERP for OCD adapted for autism. In the active comparator arm, participants will receive 12 modules of therapist- and parent-guided I-SM. Participants in the comparator group will be offered to cross-over to the I-ERP intervention after the primary endpoint.

Participants will complete outcome measures at baseline (week 0), post-treatment (week 12), and 3- and 6-months post-treatment. The primary outcome variable is the clinician-reported Children's Yale Brown-Obsessive Compulsive Scale (CY-BOCS), and the primary endpoint is the 3-month follow-up after treatment.

Secondary outcomes include measures of self-reported OCD symptoms, family accommodation, functional impairment, and depressive symptoms. Health-related quality of life and resource use will be collected for the health economic evaluation. Follow-up assessments will be conducted at the clinic or via videoconferencing, in both cases complemented with online questionnaires.

A subset of participants will participate in a process evaluation of the I-ERP intervention.

Sample: A total of 220 autistic children and adolescents diagnosed with OCD and their primary caregivers.

Statistical methodology and analysis: Data will be analysed using a pre-specified intention-to-treat statistical analysis plan. The primary outcome will be analysed using a linear mixed effects model. Secondary outcomes will be analysed using analogous methods. A health economic evaluation of the intervention from the health organisation payer, health care sector, and societal perspectives will also be conducted, as well as a process evaluation including both quantitative and qualitative measures.

• Clinical Global Impression - Severity (CGI-S) [Срок оценки: Baseline (week 0), post treatment (week 12), 3-months follow-up, 6-months follow up.]
• Clinical Global Impression - Improvement (CGI-I) [Срок оценки: Post treatment (week 12), 3-months follow-up, 6-months follow up.]
• Treatment response and remission [Срок оценки: Post treatment (week 12), 3-months follow-up, 6-months follow up.]
• Children's Global Assessment Scale (CGAS) [Срок оценки: Baseline (week 0), post treatment (week 12), 3-months follow-up, 6-months follow up.]
• Obsessive-Compulsive Inventory - Child version - revised (OCI-CV-R) [Срок оценки: Baseline (week 0), during treatment (week 3, week 6, week 9), post treatment (week 12), 3-months follow-up, 6-months follow up.]
• Children's Obsessive-Compulsive Inventory-Revised-Parent version (ChOCI-R-P) [Срок оценки: Baseline (week 0), during treatment (week 3, week 6, week 9), post treatment (week 12), 3-months follow-up, 6-months follow up.]
• Generalized Anxiety Disorder - 7 item scale (GAD-7) [Срок оценки: Baseline (week 0), post treatment (week 12), 3-months follow-up, 6-months follow up.]
• Child Health Utility 9D (CHU9D) [Срок оценки: Baseline (week 0), post treatment (week 12), 3-months follow-up, 6-months follow up.]
• Trimbos/iMTA Questionnaire for Costs associated with Psychiatric Illness (TiC-P) [Срок оценки: Baseline (week 0), post treatment (week 12), 3-months follow-up, 6-months follow up.]
• Patient Exposure/Relaxation Adherence Scale (PEAS/PRAS) [Срок оценки: During treatment (week 3, week 6, week 9), post treatment (week 12), 3-months follow-up.]
• Treatment preference [Срок оценки: Baseline (week 0), post treatment (week 12).]
• Treatment Credibility and Expectancy Scale (TCES) [Срок оценки: During treatment (week 3).]