Effectiveness of a Guided, Web-based, Stepped-care-approach to Cognitive Behavioral Therapy for Insomnia in Cancer Survivors

Healthcare use is assessed using the Medical Consumption Questionnaire (MCQ), which records the frequency and type of healthcare services used by participants, including sleep-related healthcare consumption. Outcomes are expressed as the number of healthcare contacts or services used during the specified recall period. Higher values indicate greater healthcare use.

Productivity loss is assessed using the Productivity Cost Questionnaire (PCQ), which measures productivity loss due to absenteeism and presenteeism. Outcomes are expressed as the number of hours of productivity loss, with higher values indicating greater productivity loss (worse outcome).

Sleep quality is assessed using the Pittsburgh Sleep Quality Index (PSQI), which evaluates subjective sleep quality and sleep disturbances over the past month. The PSQI global score ranges from 0 to 21, with higher scores indicating poorer sleep quality (worse outcome)

Health-related quality of life is assessed using the EuroQol 5-Dimension 5-Level Questionnaire (EQ-5D-5L), which evaluates health status across five dimensions: mobility, self-care, usual activities, pain/discomfort, and anxiety/depression. The health utility score ranges from -0.532 to 1, with higher scores indicating better health-related quality of life. A score of 1 represents full health, while 0 represents death; negative values represent health states valued as worse than death, based on the Belgian EQ-5D-5L value set developed by Bouckaert et al.

Pain intensity is assessed using the Pain Visual Analogue Scale (VAS). Participants rate their pain over the past 2 weeks on a scale ranging from 0 to 10, with 0 indicating no pain and 10 indicating the worst pain imaginable. The minimum score is 0 and the maximum score is 10, with higher scores indicating greater pain intensity (worse outcome).y.

Symptoms of central sensitization are assessed using the Central Sensitization Inventory (CSI), a validated 25-item questionnaire. The total score ranges from 0 to 100, with higher scores indicating greater severity of central sensitization-related symptoms (worse outcome).

Fatigue is assessed using the Brugmann Fatigue Scale (BFS), an 8-item questionnaire assessing mental and physical fatigue. Each item is scored from 0 to 3. The Mental Fatigue subscale and Physical Fatigue subscale each range from 0 to 12, with higher scores indicating greater fatigue and greater propensity to rest (worse outcome).

Daytime sleepiness is assessed using the Epworth Sleepiness Scale (ESS), an 8-item questionnaire. Each item is scored from 0 to 3, resulting in a total score ranging from 0 to 24, with higher scores indicating greater daytime sleepiness (worse outcome).

Dysfunctional beliefs and attitudes about sleep are assessed using the 16-Item Dysfunctional Beliefs and Attitudes About Sleep Scale (DBAS-16). Each of the 16 items is rated from 0 to 10, with higher scores indicating stronger endorsement of dysfunctional beliefs and attitudes about sleep (worse outcome).

Subjective sleep quality is assessed using a Sleep Visual Analogue Scale (VAS). Participants rate their sleep quality over the past 2 weeks on a scale ranging from 0 to 10, with 0 indicating very poor sleep quality and 10 indicating excellent sleep quality. Higher scores indicate better subjective sleep quality.

Sleep chronotype is assessed using the Munich Chronotype Questionnaire (MCTQ). Chronotype is estimated using the sleep-corrected midpoint of sleep on free days (MSFsc), expressed as clock time. MSFsc represents the midpoint of sleep on free days corrected for sleep debt accumulated during workdays. Earlier clock times indicate an earlier chronotype, while later clock times indicate a later chronotype.

Pain severity is assessed using the Brief Pain Inventory (BPI) through four items assessing worst pain, least pain, average pain, and pain right now. Each item is scored from 0 (no pain) to 10 (pain as bad as you can imagine). The mean pain severity score ranges from 0 to 10, with higher scores indicating greater pain severity (worse outcome).

Health-related quality of life is assessed using the European Organisation for Research and Treatment of Cancer Quality of Life Questionnaire-Core 30 (EORTC QLQ-C30). The global health status/quality of life scale is scored from 0 to 100, with higher scores indicating better health-related quality of life.

Depressive symptoms are assessed using the Depression subscale of the Depression Anxiety Stress Scale-21 (DASS-21). The subscale consists of 7 items, each scored from 0 (did not apply to me at all) to 3 (applied to me very much, or most of the time). The scores are summed and multiplied by 2, resulting in a total score ranging from 0 to 42. Higher scores indicate more severe depressive symptoms (worse outcome).

Anxiety symptoms are assessed using the Anxiety subscale of the Depression Anxiety Stress Scale-21 (DASS-21). The subscale consists of 7 items, each scored from 0 (did not apply to me at all) to 3 (applied to me very much, or most of the time). The scores are summed and multiplied by 2, resulting in a total score ranging from 0 to 42. Higher scores indicate more severe anxiety symptoms (worse outcome).

Stress symptoms are assessed using the Stress subscale of the Depression Anxiety Stress Scale-21 (DASS-21). The subscale consists of 7 items, each scored from 0 (did not apply to me at all) to 3 (applied to me very much, or most of the time). The scores are summed and multiplied by 2, resulting in a total score ranging from 0 to 42. Higher scores indicate more severe stress symptoms (worse outcome).

Bodily threat monitoring is assessed using the validated Bodily Threat Monitoring Scale (BTMS). The scale assesses the tendency to monitor bodily sensations and concerns about bodily sensations. The total score ranges from 0 to 24, with higher scores indicating a greater tendency to monitor bodily sensations.

Fear of cancer recurrence is assessed using the 42-item Fear of Cancer Recurrence Inventory (FCRI). The FCRI consists of 42 items rated on a 5-point scale from 0 to 4. The total score ranges from 0 to 168, with higher scores indicating greater fear of cancer recurrence (worse outcome).

Perceptions of insomnia are assesed using three self-designed study-specific questions which are based on the Ilness Cognition Questionnaire (ICQ). Self-designed study specific questions were used to reduce patient burden. Participants rate their response on a scale from 0 to 100, with 0 indicating that insomnia perceptions are not negatively impacting their life and 100 indicating that insomnia has a significant impact on their lives. Higher scores indicate greater perceived negative outcomes related to insomnia.

Perceptions of cancer are assesed using three self-designed study-specific questions which are based on the Ilness Cognition Questionnaire (ICQ). Self-designed study specific questions were used to reduce patient burden. Participants rate their response on a scale from 0 to 100, with 0 indicating that cancer perceptions are not negatively impacting their life and 100 indicating that cancer has a significant impact on their lives. Higher scores indicate greater perceived negative outcomes related to cancer.

Physical fatigue is assessed using the Physical Fatigue subscale of the Multidimensional Fatigue Inventory (MFI). The subscale consists of 4 items, with a total score ranging from 4 to 20. Higher scores indicate greater physical fatigue (worse outcome).

Mental fatigue is assessed using the Mental Fatigue subscale of the Multidimensional Fatigue Inventory (MFI). The subscale consists of 4 items, with a total score ranging from 4 to 20. Higher scores indicate greater mental fatigue (worse outcome).

Reduced motivation is assessed using the Reduced Motivation subscale of the Multidimensional Fatigue Inventory (MFI). The subscale consists of 4 items, with a total score ranging from 4 to 20. Higher scores indicate greater reduction in motivation.

Reduced activity is assessed using the Reduced Activity subscale of the Multidimensional Fatigue Inventory (MFI). The subscale consists of 4 items, with a total score ranging from 4 to 20. Higher scores indicate greater reduction in activity.

Pain interference is assessed using the Brief Pain Inventory (BPI) through seven items assessing interference with general activity, mood, walking ability, normal work, relations with other people, sleep, and enjoyment of life. Each item is scored from 0 (does not interfere) to 10 (completely interferes). The mean pain interference score ranges from 0 to 10, with higher scores indicating greater pain interference (worse outcome).

Perceived Injustice is assed by use of the Injustice Experience Questionnaire (IEQ). The Injustice experience Questionnaire has 12 items (ranging 0-4) with a total score ranging from 0-48. A total score on of 17 or more indicates the presence of cliniclly relevant perceived injustice by the participant.