Pilot Study of Internet-Delivered Psychological Treatment for Cancer Survivors

A key feasibility outcome of this pilot study is the overall experience of study administrators and therapists tasked with the assignment and delivery of treatment variants in accordance with the randomized factorial design. After the main phase, all study administrators and therapists will be asked to rate the feasibility of the planned study design from 0 ("not feasible at all") to 10 ("fully feasible"), which will reported as a mean (SD) and median.

Credibility/Expectancy scale (C/E scale). Theoretical range: 0-50, where a higher score indicates higher credibility/expectancy.

Number of modules initiated, as registered by the clinician.

Number of completed exercises, as based on a short weekly questionnaire tailored to suit each treatment arm, with corresponding questions about the number of days devoted to exposure exercises, days devoted to activity planning, and days devoted to the promotion of health behaviors.

Number of measurements completed at each measurement point after the pre-treatment assessment. Preregistered target: at least 70% non-missing at the post-treatment and follow-up assessments.

Perceived strain caused by the measurement strategy. Preregistered target: at least 75% with a rating below 7 from 0 ("not at all stressful/distressing") to 10 ("extremely stressful/distressing").

The 8-item Client Satisfaction Questionnaire (CSQ-8). Theoretical range: 8-32, where a higher score indicates higher satisfaction.

Likert items pertaining to satisfaction with components.

Questionnaire used in previous clinical trials (e.g., ClinicalTrials.gov: NCT04511286)

20-item Negative Effects Questionnaire (NEQ-20). This will be reported as the proportion of endorsed items in the following subdomains: increase in symptoms, perceived insufficient quality of treatment, dependency, stigma, and hopelessness.

General Anxiety Disorder 7 (GAD-7, theoretical range: 0-21, where a higher score indicates more general anxiety)

Patient Health Questionnaire 9 (PHQ-9, theoretical range: 0-27, where a higher score indicates more symptoms of depression)

9-item Fear of Cancer Recurrence Inventory (FCRI-9, theoretical range: 0-36, where a higher score indicates a more pronounced fear of cancer recurrence)

36-item Short Form Health Survey (SF-36, scored as a Mental Health Component Score and a Physical Health Component Score according to standard norms, both with a theoretical range of 0-100, where a higher score indicates a higher health-related quality of life)

14-item Health Anxiety Inventory (HAI-14, theoretical range: 0-42, where a higher score indicates more health anxiety).

Somatic Symptom Scale 8 (SSS-8, theoretical range: 0-32, where a higher score indicates a higher somatic symptom burden). Exploratory secondary analyses will be based on individual items, each scored 0-4.

Body Image Scale (BIS, theoretical range: 0-30, where a higher score indicates a higher level of body image distress).

12-item WHO Disability Assessment Schedule 2.0 (WD2-12, theoretical range: 0-100, where a higher score indicates more disability).

3-item Behavioral Activation for Depression Scale - Activation (BADS-AC-3, theoretical range: 0-18, where a higher score indicates a higher level of behavioral activation).

Symptom Preoccupation Scale (preliminary scale). A higher score indicates higher degree of preoccupation with symptoms. This is to be regarded as an an item pool, and the scale is is under development, which means that the total range cannot be preregistered.

Godin-Shephard Leisure-Time Physical Activity Questionnaire (GSLTPAQ, theoretical range 0-99, where a higher score indicates a higher level of physical activity). If necessary for statistical modeling, the GSLTPAQ will be dichotomized to indicate active (≥24) vs. insufficiently active (<24).

Based loosely on the Arthritis Self-efficacy Scale. Theoretical range of 0-60, where a higher score indicates a higher level of general health-related self-efficacy.

Working Alliance Inventory (WAI, theoretical range: 6-42, where a higher score indicates a stronger therapeutic alliance)

Alcohol Use Disorders Identification Test (AUDIT, theoretical range: 0-40, where a higher score indicates more problematic alcohol use).

Drug Use Disorders Identification Test (DUDIT, theoretical range: 0-44, where a higher score indicates more problematic substance use).

Hospital Anxiety and Depression Scale (HADS, theoretical range: 0-42, where a higher score indicates more general distress).