Table 3 Primary and secondary outcome measuresa
Primary outcome | Measurement instrument | Time points of measurement |
Functional Disability Inventory (FDI) | Baseline, 8Â weeks, 16Â weeks, 10 and 12Â months | |
Self-report measure for perceived difficulty in performing activities at school, at home and in recreational or social interactions. | ||
15 Items rated on a five-point scale (0–4). Total scores range 0–60 with a higher scores indicating greater disability. | ||
Valid and reliable measure for assessing pain related disability in adolescents. | ||
á…Ÿ | á…Ÿ | á…Ÿ |
Secondary outcomes | Measurement instrument | Time points of measurement |
Fear of pain [48] | Fear of Pain Questionnaire (FOPQ-C) | Baseline, 8Â weeks, 16Â weeks, 10 and 12Â months |
Self-report measure to assess pain-related fear in adolescents with chronic pain. 24 items rated on a five-point scale (0–4). Total scores range 0–96 with a higher score indicating more fear. Consists of subscales 1) Fear of Pain and 2) Avoidance of activities. | ||
Psychometric properties of the English version are good. | ||
Perceived harmfulness [27] | PHODA-Youth | Baseline, 8Â weeks, 16Â weeks, 10 and 12Â months |
Measures perceived harmfulness of physical and social activities and can be used to create a hierarchy of fearful activities. | ||
51 photographs are rated on a scale 0–10 (steps 0.1). The higher a photo is ranked, the more harmful the adolescent thinks executing the activity is. Consists of subscales 1) activities of daily living, 2) intensive physical activities and 3) social activities. | ||
Psychometric qualities are good. | ||
Pain Catastrophizing [49] | Pain Catastrophizing Scale (PCS-C) | Baseline, 8Â weeks, 16Â weeks, 10 and 12Â months |
Self-report measure of catastrophic thinking about pain. Frequency of feelings and thoughts adolescents may experience when they are in pain are measured. | ||
13 items rated on a five-point scale (0–4). Total scores range 0–52 with higher scores indicating more catastrophic thinking. Consists of subscales 1) Rumination, 2) Magnification, and 3) Helplessness. Reliability and validity are good. | ||
Depressive symptoms [52] | Child Depression Inventory (CDI) | Baseline, 8Â weeks, 16Â weeks, 10 and 12Â months |
Self-report measure of depressive symptoms in children and adolescents. | ||
27 items rated on a three-point scale (0–2). Total scores range 0–54 with higher scores indicating more depressive symptoms. Consists of subscales 1) Negative mood, 2) Interpersonal problems, 3) Ineffectiveness, 4) Negative self-esteem, and 5) Anhedonia. | ||
Dutch version demonstrates good reliability and validity. | ||
Pain specific quality of life [53] | Quality of Life in Adolescent with Chronic Pain (QLA-CP) | Baseline, 8Â weeks, 16Â weeks, 10 and 12Â months |
Self-reported pain-specific quality of life measure for adolescents with chronic pain. | ||
44 items in 6 domains, 1) Psychological functioning, 2) Functional status, 3) Physical status, 4) Social functioning, 5) Satisfaction with life in general, and 6) Satisfaction with health. A high score on each domain of the questionnaire represents a better quality of life. | ||
Internal consistency and construct validity have shown to be adequate. | ||
Pain Intensity [51] | Visual Analogue scale (VAS) | Baseline, 8Â weeks, 16Â weeks, 10 and 12Â months |
Self-report measure of pain intensity. Sliding scale where the ends of the line represent the extreme limits of pain intensity (no pain at all and worst pain imaginable). Average VAS score is taken of pain at this moment, worst and least pain in last week. | ||
Reliable method in children above 8Â years old. Sound psychometric properties and clinical utility. | ||
Functional Disability Inventory – Parent report (FDI) | Baseline, 8 weeks, 16 weeks, 10 and 12 months | |
Measure of parent perceived functional disability of their child. | ||
15 items rated on a five-point scale (0–4). Total scores range 0–60 with higher scores indicating greater parent-perceived difficulty in performing activities. | ||
Parent perceived Fear of Pain [48] | Fear of Pain Questionnaire – Parent report (FOPQ-P) | Baseline, 8 weeks, 16 weeks, 10 and 12 months |
Parent proxy report measure to assess parents perception of their childs pain-related fear experience. | ||
23 items rated on a five-point scale (0–4). Total scores range 0–92 with higher scores indicating a higher parent perceived fear. Consists of subscales 1) fear of pain, 2) avoidance of activities, and 3) School avoidance. | ||
Psychometrically sound measure with strong internal consistency, good construct and criterion validity. | ||
Parental Pain catastrophizing [50] | Pain Catastrophizing Scale – Parent report (PCS-P) | Baseline, 8 weeks, 16 weeks, 10 and 12 months |
Measures parental catastrophizing about their child’s pain. | ||
13 items rated on a five-point scale (0–4). Total scores range 0–52 with higher scores indicating more catastrophic thinking by the parents. | ||
Psychometric properties are good to very good. | ||
Adult response to children’s symptoms [54] | Adult response to children’s symptoms scale (ARCS) | Baseline, 8 weeks, 16 weeks, 10 and 12 months |
Parent self-report measure of a range of parental responses to pain of their child. | ||
29 items rated on a five-point scale (Never-always). Consists of subscales 1) Protective responses, 2) minimizing responses (criticizing or downplaying the pain) and 3) monitoring/encouraging responses (encouraging activity while monitoring symptoms) | ||
Valid instrument for assessing parents’ responses to children’s pain for diverse chronic pain symptoms. | ||
Other study parameters | Used in economic evaluation and process evaluation | Â |
Costs (economic evaluation) [55] | Cost diary | After treatment each month until month 12. |
Health care utilization, school absence and productivity losses are recorded. | ||
Generic health related quality of life (economic evaluation) [56] | EQ-5D-Y | Baseline, 8Â weeks, 16Â weeks, 10 and 12Â months |
Generic self-report measure of health related quality of life. | ||
5 Items, scored on three levels: no problems, moderate problems, severe problems. Contains domains 1) mobility, 2) self-care, 3) usual activities, 4) pain/discomfort, and 5) anxiety/depression. 1 visual analogue scale to rate their own health between 0 and 100 (best health state). | ||
Satisfaction/patient centeredness (Process evaluation) [58] | Giving Youth A Voice Questionnaire (GYV-20) | 16Â weeks |
The instrument has 4 themes, 1) supportive and respectful relationships, 2) Information sharing and communication, 3) Supporting independence and 4) Teen-centred service. Each item is formulated as a question, starting with ‘How much do the people who work with you…’ and then a description of a specific action or behaviour of the health care professional is given. Response options range from 1–7, with a ‘not applicable’ category added. Scale scores can be calculated as the mean of the ratings for the items in the scale. | ||
Satisfaction/family centeredness (Process evaluation) [59, 60] | Measure of Processes Of Care – Parent form – Short form (MPOC-P-20) | 16 weeks |
20 items, scored on a scale 1–7. Consists of 5 scales, 1) Enabling and Partnership, 2) Providing General Information, 3) Providing Specific Information about the Child, 4) Coordinated and Comprehensive Care for the Child and Family and 5) Respectful and Supportive Care. Responses to each item are converted to a mean for each scale. No total score can be calculated. | ||
Treatment expectations of children (Process evaluation) [61] | Credibility/Expectancy Questionnaire (CEQ-Adolescent) | Baseline |
On the 11 items (5 on credibility, 6 on expectancy) can be answered on a 9-point scale from ‘totally not’ to ‘totally’. Total scores are a sum score of the individual items and ranges from 11 to 99. | ||
Treatment expectations parents (Process evaluation) [61] | Credibility/Expectancy Questionnaire (CEQ-Parent) | Baseline |
On the 11 items (5 on credibility, 6 on expectancy) can be answered on a 9-point scale from ‘totally not’ to ‘totally’. Total scores are a sum score of the individual items and ranges from 11 to 99. | ||
Birghton Criteria | Baseline | |
To identify adolescents with HMS the Brighton criteria, including a Beighton score will be used. A cut-off value of ≥5 will be used for hypermobility. |