General worry in past two weeks among adolescent and parent study participants is assessed with the General Anxiety Disorder (GAD-2) instrument. The GAD-2 has 2 items that are responded to on a 4-point scale where " not at all" = 0 and "nearly every day" = 3. Total scores range from 0 to 6 where higher scores indicate increased experiences of worry.

Exaggerated worried thoughts of pain are assessed among adolescent and parent study participants. The Pain Catastrophizing Scale, Child and Parent Report, is a 13-item well-validated self-report and parent-report measure of worried thoughts about pain. Items are answered on a 5-point scale where 0 = not true at all and 4 = very true. Total scores range from 0 to 52 and higher scores indicate increased catastrophic thinking.

Health-related quality of life and impact on child and family in the past month is assessed among adolescent study participants with the Pediatric Quality of Life Inventory (PedsQL). The 23-item PedsQL was developed as part of the NIH Roadmap Initiative to create universal measures for patient-reported outcomes and contains questions in the domains of social-peer, depression, anxiety, mobility, and function. Responses are given on a 5-point scale where 0 = never and 4 = almost always. Items are reverse scored and linearly transformed to a scale of 0 to 100, where higher total mean scores indicate a better quality of life.

The Adolescent Sleep Wake Scale (ASWS) is a 28-item patient-reported describing the occurrence and frequency of various behavioral sleep characteristics over the past month. Responses are given on a 6-point Likert scale where 1 = always and 6 = never. Total scores range from 28 to 168 and higher scores indicate better sleep quality.

Substance use among adolescent study participants during the past 3 months is assessed with the NIDA-Modified Assist Tool Level 2 for children aged 11-17. The instrument asks respondents how often they have used 15 different substances. Responses are given on a 5-point scale where "not at all" = 0, "less than a day or two" = 1, "several days" = 2, "more than half the days" = 3, and "nearly every day" = 4. Responses to items were then scored as either 0 for non-use of a particular substance or 1 for any use of a particular substance (encompassing scale scores of 1 - 4). The tool is scored as the number of items with a score of greater than 0. The total score ranges from 0 to 15 with higher values indicating use of a greater number of substances.

Daily use of opioid pain medication is determined based on participant completion of daily diaries for one week at each assessment visit. Participants record opioid use daily as presence or absence of use.

The overall self-reported rating of the efficacy of treatment is assessed with the Patient Global Impression of Change (PGIC) instrument. The PGIC asks respondents to rate their overall improvement compared to baseline. Responses are given on a scale of 1 to 7 where 1 = very much improved and 7 = very much worse.

The Treatment Evaluation Inventory-Short Form is completed at the end of treatment. It includes 9 items adapted to be specific to pediatric pain. Items are rated on a 5-point Likert scale ranging from 1 to 5. Total scores range from 9 to 45. Higher scores indicate increased acceptability with the study treatment.

Fear of movement related to fear of pain is assessed with the Tampa Scale of Kinesiophobia (TSK) instrument. The TSK is a 17-item questionnaire where responses are given on a 4-point Likert scale. Responses of "strongly agree" are coded as 1 and responses of "strongly agree" are coded as 4. Total scores range from 17 to 68 where higher scores indicate greater kinesiophobia.

Adolescents with sickle cell disease participating in the I-STRONG intervention. I-STRONG for SCD is a group-based, multi-component intervention that includes mind-body, cognitive-behavioral, and neuromuscular movement training. The intervention includes 16 sessions that occur over 8 weeks. Adolescents attend each of the 16 sessions.

Parents of adolescents with sickle cell disease participating in the I-STRONG intervention. Parents are enrolled when the adolescent is under the age of 18. I-STRONG for SCD is a group-based, multi-component intervention that includes mind-body, cognitive-behavioral, and neuromuscular movement training. The intervention includes 16 sessions that occur over 8 weeks. Parents attend 6 of the 16 sessions.

Total of all reporting groups

Sickle cell disease genotype is only relevant for adolescent participants with sickle cell disease. Genotypes HbSS and HbSβ0 thalassemia are generally the most severe forms of SCD.

Functional interference due to pain rated with the impact of pain on daily functions item of the Brief Pain Inventory (BPI). The single item is scored on a scale from 0 to 10 where no pain = 0 and severe pain = 10.

The analysis population includes adolescent participants who completed the indicated study visit and completed the survey. One participant withdrew prior to the post-treatment assessment at Week 8, an additional participant declined to complete the surveys at the 3 months post-treatment assessment at Month 5, and one participant did not complete this survey during the 3 months post-treatment assessment.

Depressive symptoms in past two weeks among adolescent and parent study participants is assessed with the Patient Health Questionnaire (PHQ-8). The PHQ-8 has 8 items that are responded to on a 4-point scale where " not at all" = 0 and "nearly every day" = 3. Total scores range from 0 to 24 where higher scores indicate increased symptoms of depression.

The analysis population includes adolescent and adult participants who completed the indicated study visit and completed the survey. One adolescent participant withdrew prior to the post-treatment assessment at Week 8 and an additional participant declined to complete the surveys at the 3 months post-treatment assessment at Month 5.

General worry in past two weeks among adolescent and parent study participants is assessed with the General Anxiety Disorder (GAD-2) instrument. The GAD-2 has 2 items that are responded to on a 4-point scale where " not at all" = 0 and "nearly every day" = 3. Total scores range from 0 to 6 where higher scores indicate increased experiences of worry.

The analysis population includes adolescent and adult participants who completed the indicated study visit and completed the survey. One adolescent participant withdrew prior to the post-treatment assessment at Week 8 and an additional participant declined to complete the surveys at the 3 months post-treatment assessment at Month 5.

Exaggerated worried thoughts of pain are assessed among adolescent and parent study participants. The Pain Catastrophizing Scale, Child and Parent Report, is a 13-item well-validated self-report and parent-report measure of worried thoughts about pain. Items are answered on a 5-point scale where 0 = not true at all and 4 = very true. Total scores range from 0 to 52 and higher scores indicate increased catastrophic thinking.

The analysis population includes adolescent and adult participants who completed the indicated study visit and completed the survey. One adolescent participant withdrew prior to the post-treatment assessment at Week 8 and an additional participant declined to complete the surveys at the 3 months post-treatment assessment at Month 5.

Health-related quality of life and impact on child and family in the past month is assessed among adolescent study participants with the Pediatric Quality of Life Inventory (PedsQL). The 23-item PedsQL was developed as part of the NIH Roadmap Initiative to create universal measures for patient-reported outcomes and contains questions in the domains of social-peer, depression, anxiety, mobility, and function. Responses are given on a 5-point scale where 0 = never and 4 = almost always. Items are reverse scored and linearly transformed to a scale of 0 to 100, where higher total mean scores indicate a better quality of life.

The analysis population includes adolescent participants who completed the indicated study visit and completed the survey. One participant withdrew prior to the post-treatment assessment at Week 8 and an additional participant declined to complete the surveys at the 3 months post-treatment assessment at Month 5. This survey was not administered to parents.

The Adolescent Sleep Wake Scale (ASWS) is a 28-item patient-reported describing the occurrence and frequency of various behavioral sleep characteristics over the past month. Responses are given on a 6-point Likert scale where 1 = always and 6 = never. Total scores range from 28 to 168 and higher scores indicate better sleep quality.

The analysis population includes adolescent participants who completed the indicated study visit and completed the survey. One participant withdrew prior to the post-treatment assessment at Week 8 and an additional participant declined to complete the surveys at the 3 months post-treatment assessment at Month 5.

Substance use among adolescent study participants during the past 3 months is assessed with the NIDA-Modified Assist Tool Level 2 for children aged 11-17. The instrument asks respondents how often they have used 15 different substances. Responses are given on a 5-point scale where "not at all" = 0, "less than a day or two" = 1, "several days" = 2, "more than half the days" = 3, and "nearly every day" = 4. Responses to items were then scored as either 0 for non-use of a particular substance or 1 for any use of a particular substance (encompassing scale scores of 1 - 4). The tool is scored as the number of items with a score of greater than 0. The total score ranges from 0 to 15 with higher values indicating use of a greater number of substances.

The analysis population includes adolescent participants who completed the indicated study visit and completed the survey. One participant withdrew prior to the post-treatment assessment at Week 8 and an additional participant declined to complete the surveys at the 3 months post-treatment assessment at Month 5.

Daily use of opioid pain medication is determined based on participant completion of daily diaries for one week at each assessment visit. Participants record opioid use daily as presence or absence of use.

The analysis population includes participants who completed any number of days of the daily diaries for the indicated time point. Some participants did not complete any diary days.

The overall self-reported rating of the efficacy of treatment is assessed with the Patient Global Impression of Change (PGIC) instrument. The PGIC asks respondents to rate their overall improvement compared to baseline. Responses are given on a scale of 1 to 7 where 1 = very much improved and 7 = very much worse.

The analysis population includes adolescent participants who completed the indicated study visit and completed the survey. One participant withdrew prior to the post-treatment assessment at Week 8 and two additional participants declined to complete this survey at the 3 months post-treatment assessment at Month 5.

The Treatment Evaluation Inventory-Short Form is completed at the end of treatment. It includes 9 items adapted to be specific to pediatric pain. Items are rated on a 5-point Likert scale ranging from 1 to 5. Total scores range from 9 to 45. Higher scores indicate increased acceptability with the study treatment.

The analysis population includes adolescent participants who completed the indicated study visit and completed the survey. One participant withdrew prior to the post-treatment assessment at Week 8 and an additional participant declined to complete the surveys at the 3 months post-treatment assessment at Month 5. This survey was not administered to parents.

Fear of movement related to fear of pain is assessed with the Tampa Scale of Kinesiophobia (TSK) instrument. The TSK is a 17-item questionnaire where responses are given on a 4-point Likert scale. Responses of "strongly agree" are coded as 1 and responses of "strongly agree" are coded as 4. Total scores range from 17 to 68 where higher scores indicate greater kinesiophobia.

The analysis population includes adolescent participants who completed the indicated study visit and completed the survey. One participant withdrew prior to the post-treatment assessment at Week 8 and an additional participant declined to complete the surveys at the 3 months post-treatment assessment at Month 5.