Brief Pain Inventory (BPI) - 7 items of pain interference
Time frame: Pre-intervention (baseline), post-intervention (8 weeks after baseline), and follow-up (one month post-intervention)
The Brief Pain Inventory (BPI) pain interference subscale is a self-report measure used to assess the extent to which pain interferes with daily functioning. It comprises seven items assessing general activity, mood, walking ability, normal work, relations with others, sleep, and enjoyment of life. Each item is rated on an 11-point numerical rating scale ranging from 0 ("does not interfere") to 10 ("completely interferes"). The overall pain interference score is calculated as the mean of the seven items and ranges from 0 to 10, with higher scores indicating greater pain-related interference and therefore a worse outcome.
The Hospital Anxiety and Depression Scale (HADS)
Time frame: Pre-intervention (baseline), post-intervention (8 weeks after baseline), and follow-up (one month post-intervention)
The Hospital Anxiety and Depression Scale (HADS) is a 14-item self-report questionnaire designed to assess symptoms of anxiety and depression in non-psychiatric hospital populations. It comprises two seven-item subscales: the Hospital Anxiety and Depression Scale-Anxiety subscale (HADS-A) and the Hospital Anxiety and Depression Scale-Depression subscale (HADS-D). Each item is rated on a 4-point scale ranging from 0 to 3. Scores for each subscale are calculated by summing the seven corresponding items and range from 0 to 21, with higher scores indicating greater anxiety or depressive symptom severity and therefore a worse outcome.
Pain Self-Efficacy Questionnaire (PSEQ)
Time frame: Pre-intervention (baseline), post-intervention (8 weeks after baseline), and follow-up (one month post-intervention)
The Pain Self-Efficacy Questionnaire (PSEQ) is a 10-item self-report measure designed to assess individuals' confidence in performing daily activities despite chronic pain. Each item is rated on a 7-point scale ranging from 0 ("not at all confident") to 6 ("completely confident"). Item scores are summed to produce a total score ranging from 0 to 60, with higher scores indicating greater pain self-efficacy and therefore a better outcome.
Pain Catastrophizing Scale (PCS)
Time frame: Pre-intervention (baseline), post-intervention (8 weeks after baseline), and follow-up (one month post-intervention)
The Pain Catastrophizing Scale (PCS) is a 13-item self-report questionnaire designed to assess negative thoughts and feelings related to pain. It comprises three subscales: rumination, magnification, and helplessness. Each item is rated on a 5-point scale ranging from 0 ("not at all") to 4 ("all the time"). Item scores are summed to produce a total score ranging from 0 to 52, with higher scores indicating greater pain catastrophizing and therefore a worse outcome.
Fear-Avoidance Beliefs Questionnaire (FABQ)
Time frame: Pre-intervention (baseline), post-intervention (8 weeks after baseline), and follow-up (one month post-intervention)
The Fear-Avoidance Beliefs Questionnaire (FABQ) is a 16-item self-report measure designed to assess beliefs about how physical activity and work may affect pain. Eleven items are included in the scoring of two subscales: the four-item Fear-Avoidance Beliefs Questionnaire-Physical Activity subscale (FABQ-PA) and the seven-item Fear-Avoidance Beliefs Questionnaire-Work subscale (FABQ-W). Each item is rated on a 7-point scale ranging from 0 ("completely disagree") to 6 ("completely agree"). Item scores are summed separately for each subscale. The FABQ-PA score ranges from 0 to 24, and the FABQ-W score ranges from 0 to 42. Higher scores indicate stronger fear-avoidance beliefs related to physical activity or work and therefore a worse outcome.
The Satisfaction with Life Scale (SWLS)
Time frame: Pre-intervention (baseline), post-intervention (8 weeks after baseline), and follow-up (one month post-intervention)
The Satisfaction With Life Scale (SWLS) is a five-item self-report questionnaire designed to assess overall cognitive judgments of life satisfaction. Each item is rated on a 7-point scale ranging from 1 ("strongly disagree") to 7 ("strongly agree"). Item scores are summed to produce a total score ranging from 5 to 35, with higher scores indicating greater life satisfaction and therefore a better outcome.
Toronto Alexithymia Scale (TAS)
Time frame: Pre-intervention (baseline), post-intervention (8 weeks after baseline), and follow-up (one month post-intervention)
The 20-Item Toronto Alexithymia Scale (TAS-20) is a self-report questionnaire designed to assess alexithymia-related traits across three dimensions: difficulty identifying feelings, difficulty describing feelings, and externally oriented thinking. Each item is rated on a 5-point scale ranging from 1 ("strongly disagree") to 5 ("strongly agree"). After reverse-scoring the relevant items, item scores are summed to produce a total score ranging from 20 to 100, with higher scores indicating greater levels of alexithymia and therefore a worse outcome.
The Pittsburgh Sleep Quality Index (PSQI)
Time frame: Pre-intervention (baseline), post-intervention (8 weeks after baseline), and follow-up (one month post-intervention)
The Pittsburgh Sleep Quality Index (PSQI) is a 19-item self-report questionnaire designed to assess sleep quality and sleep disturbances over the previous month. The items are used to derive seven component scores: subjective sleep quality, sleep latency, sleep duration, habitual sleep efficiency, sleep disturbances, use of sleep medication, and daytime dysfunction. Each component is scored from 0 to 3, and the seven component scores are summed to produce a global score ranging from 0 to 21. Higher scores indicate poorer sleep quality and greater sleep disturbance and therefore a worse outcome.
The Fatigue Severity Scale (FSS)
Time frame: Pre-intervention (baseline), post-intervention (8 weeks after baseline), and follow-up (one month post-intervention)
The Fatigue Severity Scale (FSS) is a nine-item self-report questionnaire designed to assess fatigue severity and its impact on motivation, physical activity, work, and daily functioning. Each item is rated on a 7-point scale ranging from 1 ("strongly disagree") to 7 ("strongly agree"). The overall score is calculated as the mean of the nine items and ranges from 1 to 7, with higher scores indicating greater fatigue severity and therefore a worse outcome.
The Patient Global Impression of Change (PGIC)
Time frame: Post-intervention (8 weeks after baseline), and follow-up (one month post-intervention)
The Patient Global Impression of Change (PGIC) is a single-item self-report measure designed to assess the participant's overall perceived change in their condition since the beginning of treatment. Participants rate their change on a 7-point scale ranging from 1 ("no change at all") to 7 ("very much improved"). Higher scores indicate greater perceived improvement.
Medical cannabis consumption
Time frame: Pre-intervention (baseline), post-intervention (8 weeks after baseline), and follow-up (one month post-intervention)
One question was developed specifically for this study to assess the frequency of cannabis use: "How frequently do you use cannabis during a typical week?"
Health care use
Time frame: Pre-intervention (baseline), post-intervention (8 weeks after baseline), and follow-up (one month post-intervention)
Four questions were developed specifically for this study to assess participants' regular medication use, the types and frequency of treatments received, and the number of physician visits during the previous three months.