ICBT for OCD in Children With Autism

The CY-BOCS is a semi-structured clinician-administered scale used to assess the severity of OCD symptoms in children and adolescents. The scale consists of a checklist of obsessions and compulsions, 10 items assessing the severity of the OCD symptoms, and a series of ancillary items (e.g., level of insight, avoidance). Range: 0-40, lower scores mean better outcome.

Used to provide an overall rating of the OCD severity. Clinician-rated. Range: 1-7, lower scores mean better outcome.

Used to assess global improvement. Clinician-rated. Range: 1-7, lower scores mean better outcome.

Treatment response will be defined as at least 35% reduction on the CY-BOCS and a CGI-I score of 1 (very much improved) or 2 (much improved). Remission will be defined as a score of less than or equal to 12 on the CY-BOCS and a CGI-S rating of 1 (normal, not at all ill) or 2 (borderline mentally ill).

The CGAS is a single item 1-100 scale that integrates psychological, social, and academic functioning in children as a measure of psychiatric disturbance. Higher scores mean better outcome. It will be used in this trial to provide an assessor-rated opinion of global improvement (not restricted to OCD symptoms).

The OCI-CV-R is an 18-item self-reported measure of OCD symptoms. Each item is scored on a 3-point scale (0=never, 1=sometimes, 2=always). The OCI-CV-R generates a total score ranging from 0-36 points and five sub-scores (doubting/checking, obsessing, washing, ordering, and neutralizing), with higher scores indicating greater OCD symptom severity.

The ChOCI-R-P is a parent-rated measure of OCD symptom severity that includes a checklist and a severity rating with 12 items, yielding a total score of 0-48 with higher scores indicating greater OCD symptom severity.

The GAD-7 is a measure of anxiety rated by the child/adolescent. It consists of 7 items and each item is rated from 0=not at all to 3=almost every day, yielding a total score of 0-21. Lower scores mean better outcome.

The CHU9D is a 9-item measure of quality of life rated by the child/adolescent. Each item is scored from 1 to 5, assessing children's functioning "today" across domains of worry, sadness, pain, tiredness, annoyance, school, sleep, daily routine and activities. Scores are converted to utility weights using a scoring algorithm. Weights range between 0 (denoting the health state "dead") and 1 (denoting the health state "perfect health"). Weights are then used to estimate quality adjusted life years (QALY) to be used in the health economic evaluation.

The TiC-P will be used to assess healthcare and societal resource use for the health economic evaluation. The questionnaire includes items on healthcare resource use (e.g., healthcare visits), supportive resources (e.g., private tutoring), medications, prescription-free drugs, school absenteeism, academic productivity loss, and parental productivity loss and is frequently used in health economic studies. The TiC-P version used in the study has been adapted by the research team for the use among young people and parents and used in previous trials. No scores as such are available for this measure. Parent rated.

The PEAS/PRAS is a self-rated 3-item measure of patient adherence to exposure with response prevention (PEAS) with 3 items rated from 0 to 6, yielding a total score of 0-18, where higher scores indicate greater adherence. For the current trial, the measure will be administered as a self- rated version in the I-ERP group. A corresponding version (PRAS) has been developed by the research team and will be administered to participants in the control group to assess adherence to I-SM intervention.

The PEAS/PRAS is a 3-item measure of patient adherence to exposure and response prevention (PEAS) or relaxation training (PRAS). The PEAS/PRAS is one single measure but it is adapted to each of the two arms. The PEAS/PRAS has 3 items rated from 0 to 6, yielding a total score of 0-18. Higher scores mean better outcome. For the current trial, the PEAS will be administered as a self-rated version in the I-ERP group and the PRAS will be administered as a self-rated version in the I-SM group.

Two items will be administered to both the participant and the parent to assess treatment format preference (i.e., if the participant/parent would have preferred to receive internet-delivered treatment or in-person treatment for his/her symptoms or if it does not matter), as well as how important the participant and parent believe it is to be able to choose which treatment format they receive (rated on a 5-point scale). The questionnaire has been developed by the research team.

The TCES will be administered to both the participant and the parent to assess the treatment credibility and expectancy of treatment outcome. The TCES includes 5 items rated from 0 to 10, yielding a total score of 0-40, where higher scores indicate higher credibility.

The WAI is a measure of perceived working alliance with the therapist that includes 6 items rated from 1=never to 7=always, yielding a total score of 7-49. It will be administered to both the participant and the parent. Higher scores mean better working alliance.

The CSQ-8 is an 8-item measure of treatment satisfaction. Each item is rated from 1 to 4, yielding a total score of 9-36. Higher scores mean more satisfaction. It will be administered to both the participant and the parent.

The FAS-SR is a measure of family accommodation that includes 19 items about family accommodation. For the purpose of this trial, the checklist with obsessions and compulsions has been excluded, since it is not included in the total severity score and overlaps with the checklist in the ChOCI-R-P. Each item is rated from 0=none/never to 4=every day, yielding a total score of 0-76. Higher scores are associated with greater levels of family accommodation.

The WSAS-Y is a 5-item measure of functional impairment rated by the child/adolescent. Each item is rated from 0=not at all to 8=severely impaired, yielding a total score of 0-40. Lower scores mean better outcome.

The WSAS-P is a 5-item measure of functional impairment rated by the parent. Each item is rated from 0=not at all to 8=severely impaired, yielding a total score of 0-40. Lower scores mean better outcome.

The SMFQ-C is a measure of depressive symptoms rated by the child/adolescent. It consists of 13 items and each item is scored on a 3-point scale (0=not true, 1=sometimes, 2=true). The total score is derived by adding up the values for each 13 items, yielding a total score of 0-26 points. Lower scores mean better outcome. For this trial, an item has been added aimed to assess suicide risk.

The SMFQ-P is a measure of depressive symptoms rated by the parent. It consists of 13 items and each item is scored on a 3-point scale (0=not true, 1=sometimes, 2=true). The total score is derived by adding up the values for each 13 items, yielding a total score of 0-26 points. Lower scores mean better outcome.

Following the inclusion assessment, the assessor enters baseline information into the trial database. This includes information on e.g., age, primary responsible caregiver assisting during the treatment, general cognitive ability, comorbid diagnoses, distance to the clinic in kilometres, age of OCD onset, history of suicide attempt, family history of OCD and ASD, family history of other psychiatric disorders, current medication for ASD, OCD or other psychiatric disorder, and previous psychological treatment for OCD or other psychiatric disorders.

At baseline, the parent/caregiver will answer a questionnaire designed by the research team asking about e.g., the caregiver's relation to the child, who the child lives with, the child's sex and gender, number of siblings, the caregivers' educational level, the caregivers' occupation, the country in which the child and caregivers were born, how the caregiver learned about the trial, and if the child has been in previous contact with health care services due to her/his OCD or other psychiatric symptoms.

Psychiatric diagnoses at baseline, including OCD, will be based on DSM-5 diagnostic criteria and assessed with the Diagnostic Interview for Anxiety, Mood, and OCD and Related Neuropsychiatric Disorders-Child and Adolescent Version (DIAMOND-KID).

The SCQ is a parent-rated measure of autistic symptoms that includes 40 items, yielding a total score of 0-40.

Two subtests, matrix reasoning and similarities, from the WISC-V or WAIS-IV will be used to provide an estimate of full IQ.

To assess what other treatments the child/adolescent is accessing during the trial period, the family is interviewed by the assessor at post-treatment and subsequent follow-ups. This includes questions about medications (type, dose, indication, and time period) and psychological treatment (type, number of sessions, indication, and time period).

A questionnaire will be administered to systematically assess adverse events at mid-treatment, post-treatment, 3-month follow-up, and 6-month follow-up. The questionnaire is developed by the research team and includes a checklist with expected adverse events based on previous trials as well as a free text box where other, not listed adverse events can be registered.

The assessor will evaluate school absenteeism during the past month at all assessment points. The assessor will ask the participant and the caregiver if the participant has full, partial or no school attendance (i.e., school drop-out).

Usage data will be extracted from the BASS platform and entered into the trial database. These data are collected manually for each participant, including number of logins, number of messages sent to the therapist, and the name of the therapist.

The therapist time spent on each participant will be logged.

Descriptive statistics on the proportion of individuals in each group having completed at least 4 modules will be reported.