Table 1 Primary and Secondary Effectiveness Measures

Self-management

TRANSITION-Q

A 14-item generic tool to capture self-management skills in adolescents (12–18 year olds) with chronic conditions. Response options are: 2 (“Always”), 1 (“Sometimes”) or 0 (“Never”). Items are transformed to a 0–100 scale, with higher scores indicate greater self-management. Psychometrics: Person Separation Index = 0.82; no differential item function by age or gender; low residual correlations between items; Cronbach's α = 0.85; test–retest reliability = 0.90. This tool has also been used in JIA and pediatric pain populations [48, 49].

HRQL

PedsQL Arthritis Module [50]

A 22-item multidimensional scale (pain and hurt, daily activities, treatment, worry, and communication), rated using a 5-point Likert scale ranging from 0 (“never a problem”) to 4 (“almost always a problems”). Items are reverse scored and linearly transformed to a 0–100 scale, with higher scores indicating better HRQOL. Psychometrics: internal consistency α = 0.75–0.86, ability to distinguish between healthy children and children with arthritic conditions, and responsiveness through patient change over time

Pain

PROMIS Pediatric Pain Interference – Short Form [51, 52]

A 8-item scale used to measure self-reported consequences of pain among pediatric populations with chronic conditions, rated using a 5-point Likert scale ranging from 1 (“never”) to 5 (“almost always”). Total raw scores are transformed to a standardized T-Score (population mean = 10, standard deviation = 10), with higher scores suggesting greater pain interference. Psychometrics: Item Response Theory was used to develop this tool, it has the ability to distinguish between inactive and active disease in adolescents with JIA, high pairwise correlations between patient and parent dyads (ICC = 0.8) [51, 52]. This tool has also been used in JIA and pediatric pain populations [52, 53].

Emotional distress

Screen for Child Anxiety Related Disorders [54]

A 41-item scale used to screen for anxiety disorders, rated on a 3-point scale: 0 (Not True/Hardly True), 1 (Somewhat True or Sometimes True), 3 (Very True or Often True). Includes 5 subscales: Pain Disorder or Significant Somatic Symptoms, Generalized Anxiety Disorder, Separation Anxiety Disorder, Social Anxiety Disorder and School Avoidance. Summed scores can range from 0–82, higher scores indicate higher levels of anxiety symptoms, scores ≥ 25 may indicate the presence of an anxiety disorder. Psychometrics: Good internal consistency (α = 0.95) and discriminant validity are reported. This tool has also been used in JIA and pediatric pain populations [55, 56].

Center for Epidemiologic Studies Depression Scale [57]

A 20-item scale that assess depressive symptoms in individuals between 6–17 years of age, rated on a 4-point scale, ranging from 0 (Not At All) to 3 (A Lot) – 4 items are reverse scored. Summed scores can range from 0 to 60, with higher scores suggesting increasing levels of depression. Psychometrics: internal consistency ranging from α = 0.84–0.92, concurrent validity with other validated depressive measurement tolls and good test–retest reliability [58,59,60]. This tool has also been used in JIA and pediatric pain populations [61].

Disease knowledge

Medical Issues, Exercise, Pain and Social Support [MEPS] Questionnaire [62]

A 23-item scale (4 subscales: knowledge, pain, social, exercise) used to assess JIA-specific disease knowledge, items are rated on a 11 point number rating scale [1,2,3,4,5,6,7,8,9,10]. Mean total scores range from 0 – 230, mean subscale scores range from 0 – 90 depending on the number of questions in each subscale, with higher scores indicating greater knowledge. Psychometrics: evidence of construct validity as well as test–retest reliability [62, 63].

Self-efficacy

Children’s Arthritis Self-Efficacy [64]

A 11-item scale (3 subscales: activity, symptom and emotions) that assesses an adolescents perceived ability to control or manage salient aspects of living with JIA. Items are rated on a 5-point scale, ranging from 1 (“Not at all sure”) to 5 (“Very sure”). Mean scores range from 11 – 55, mean subscale score range from 1–5, with higher scores indicating better self-efficacy [64, 65]. Psychometrics: evidence of construct validity and all 3 subscale show reasonable reliability (α = 0.85–0.90) [64, 65].

Perceived social support

PROMIS Pediatric Peer Relationship Scale – Short Form [66]

A 8-item scale used to measure the quality of self-reported peer relationships. Items are rated using a 5-point Likert scale ranging from 1 (“never”) to 5 (“almost always”). Total raw scores are transformed to a standardized T-Score (population mean = 10, standard deviation = 10), with higher scores suggesting better peer relationships. Psychometrics: Item Response Theory was used to develop this tool, good test–retest reliability (ICC = 0.81), internal consistency (α = 0.83–0.95), good construct validity and responsiveness [66, 67]. This tool has also been used in JIA and pediatric pain populations [52, 53].