Explanation for the choice of comparators

The study includes 8 different treatment arms, as specified in Table 1 below.

Table 1 Intervention treatment groupsIntervention description Introductory session

All participants assigned to treatment groups 1–7 will be invited to participate in an introductory session, which includes psychoeducation and collaborative development of goals for treatment. For treatment groups 1, 2, and 3, both youth and parents will participate in the introduction session. For treatment group 4, only the youth will participate in the introduction session. For treatment group 6, only the parent will participate in the introduction session. For treatment groups 5 and 7, the parent will participate with the youth optional.

Component 1: concussion-focused cognitive behavioral therapy (cf-CBT)

The cf-CBT component targets post-concussive symptoms including mood, pain, and sleep by teaching adolescents established evidence-based emotion regulation, relaxation, and behavioral and cognitive strategies to manage their symptoms. Homework/practice assignments are given to help adolescents apply in-session concepts to the management of their symptoms. Youth randomized to receive this component will participate in six 30-min sessions of cf-CBT.

Component 2: parenting skills training (PST)

The focus of the PST component is on the use of positive parenting skills as well as helping parents manage their own emotional distress. Parents are taught to set positive recovery expectations and to use praise or attention to increase their teen’s positive coping behaviors and decrease unhelpful coping behaviors. They are also taught positive communication skills to use with their teen, and guided to schedule pleasant events together in order to strengthen the relationship. In vivo skills practice and feedback are provided to help parents generalize and use parenting techniques. Parents randomized to receive this component will participate in six 30-min sessions of PST.

Component 3: care management (CM)

In the CM component, parents are provided support regarding advocating for their child’s needs across different contexts in the healthcare system, school, and athletic departments (including guidance regarding medication referrals), using applied problem-solving together with the skills coach to address emergent needs. Adolescents can also be involved in CM, if developmentally appropriate based on their age, independence, and interest. Of note, while the CM component engages youth and parents, treatment effects are hypothesized to result from facilitating access to supportive services including medication referrals at the organizational level. Families randomized to receive this component will participate in six 30-min sessions of CM.

Treatment groups 1–7 will receive 7–19 sessions based on their group assignment (see Table 1) and these will be delivered over 12 weeks. Each half-hour intervention session will only address one of the three unique components, and the cadence of delivery of each component (Table 2) will allow all sessions to be completed during the 12-week intervention time frame, with a maximum of 10 h of intervention for families receiving all components. Components will be interspersed to allow time to practice and use skills in between sessions, and to mimic the manner in which treatment would be delivered clinically.

Table 2 Description of intervention components and dosageUsual care for treatment group 8

Patients randomized to treatment group 8 will only receive the usual care that they seek from their health care provider, without additional intervention elements. Usual post-concussive care includes the routine use of sports medicine, rehabilitation medicine, primary care, and emergency department services, as well as the occasional use of other specialty providers (such as physical therapy or mental health).

Criteria for discontinuing or modifying allocated interventions

Participants will be allowed to discontinue receiving any of the study intervention components at any time point, but would be retained for study analyses. The dosage of intervention received will be tracked for all participants.

Strategies to improve adherence to interventions

We are using five strategies to ensure interventionist fidelity to participants’ assigned condition and minimize the risk of contamination (consistent with NIH & Template for Intervention Description and Replication (TIDieR) guidelines [33, 34] and optimization trial procedures [35]: (1) standardized interventionist training; (2) auto-generated, condition-specific charting templates generated in REDCap, so that interventionist can only document on component levels assigned to specific participants; (3) condition-specific scripts, so interventionists deliver and discuss only material assigned for that condition; (4) fidelity ratings of audio-recorded intervention sessions (~ 10%) to prevent interventionist drift; and (5) weekly interventionist meetings to review participants’ progress and intervention receipt.

Relevant concomitant care permitted or prohibited during the trial

Regardless of group assignment, participants may also receive usual care from their health care provider. Usual post-concussive care includes the routine use of sports medicine, rehabilitation medicine, primary care, and emergency department services, as well as the occasional use of other specialty providers (such as physical therapy). Patients infrequently receive mental health care. Usual care at our study sites follows the Centers for Disease Control and Prevention’s (CDC) standards of care for pediatric concussion.

Provisions for post-trial care

Participants who ask for additional resources or who present in need (e.g., more acute mental health issues emerge) will be provided with referrals to specialty care at the end of the intervention period (e.g., 3 months after baseline).

Outcomes Baseline measures Prior psychiatric history

We will collect information from participants on prior psychiatric disorders based on our experience with prior studies on adolescents and adults. We will collect information on prior history of treatment for psychiatric disorders, use of psychotropic medications, and prior post-concussive symptoms [36].

Demographic characteristics

Parents will be asked to describe family demographic characteristics such as family configuration, race, and ethnicity.

Caregiver(s)’ occupations and combined family income will be also be obtained and used as a measure of family resources.

Health service and medication utilization

Parent reports will be used to assess adolescents’ pre- and post-sports injury health service utilization. Parents will report the specific number of visits to the emergency department, primary care provider, and subspecialty providers over the prior 6 months. Parents will also report on the types of medication used by adolescents (Table 3 ).

Table 3 Study assessments, use, and administration Primary outcome measures

Health Behavior Inventory (HBI): A 20-item questionnaire that assesses concussive symptoms on a 4-point scale, ranging from “never” to “often,” and yields total scores in cognitive and somatic domains. We will use the youth-report version with established reliability and validity in youth with sports injury [37].

Pediatric Quality of Life Inventory (PedsQL): A 23-item questionnaire that assesses physical, emotional, social, and school functioning. The scale includes youth-report and parent-report versions [38,39,40].

Secondary outcome measures

Patient Health Questionnaire (PHQ-9): A 9-item questionnaire that measures the severity of depressive symptoms. Reliability and validity of the PHQ-9 have been established in pediatric populations with injury [41].

Anxiety measures (GAD-7): A 7-item standardized anxiety measure that asks youth to rate how often they have been bothered by anxiety symptoms using a 4-point Likert scale. It has been shown to have good reliability, as well as criterion, construct, factorial, and procedural validity for assessing anxiety [42].

Adolescent Sleep Wake Scale: The 10-item version of the ASWS, including domains of falling asleep, reinitiating sleep, and returning to wakefulness will be used as a measure of sleep quality, based on adolescent report [43].

Daily diary (DD): The 7-day electronic daily diary surveys will include headache, mood, and energy level measures. To assess headache frequency, adolescents will report whether or not they had a headache each day [44] and will rate intensity using an 11-point numerical rating scale (NRS-11) ranging from 0 (“no pain”) to 10 (“worst pain ever”) [45]. These headache frequency and intensity items will be texted and/or emailed in the evening. This electronic 7-day short daily survey has been used successfully to assess headache frequency and pain intensity in prior studies of adolescents [44, 46, 47].

Treatment Evaluation Inventory Short Form (TEI-SF): A 6-item self-report measure that assesses participant perceptions of acceptability and satisfaction with the treatment program on a 5-point scale ranging from “strongly disagree” to “strongly agree.” The TEI-SF has demonstrated adequate reliability and validity across a wide array of treatment studies [48].

Pediatric Inventory for Parents (PIP): The 15-item emotional distress subscale of the PIP will be used to measure the frequency and difficulty of illness-related parenting distress [49].

Potential mediators

Parent-Patient Activation Measure (P-PAM): [50]. The 10-item P-PAM will be used to assess parenting self-efficacy in advocacy within the health care system (knowledge, skills, and confidence for managing their child’s health care) [51]. The 4-point scale ranges from “disagree strongly” to “agree strongly” (e.g., “I am confident I can tell a doctor concerns I have about my child’s health”).

Adult Responses to Children’s Symptoms (ARCS): The 13-item Protect Scale and 4-item Monitor Scale from the Adult Responses to Children’s Symptoms (ARCS) [52] measure will be used to assess frequencies of parental protection and monitoring behaviors, with all items rated on a Likert scale ranging from 0 (never) to 4 (always). We adapted this measure to concussion by replacing “pain” with “concussive symptoms,” and it will be given to both adolescent and parent participants.

General Self-Efficacy Scale (GSE): This 10-item scale measures general self-efficacy on a scale of 1 (not at all true) to 4 (exactly true) on items such as “I can usually handle whatever comes my way,” with higher scores indicating greater self-efficacy [53]. Youth will provide self-report on this measure.

Participant timeline

The participant timeline is shown in Fig. 2.

Fig. 2

Consort trial flow diagram

Sample size

We plan to enroll a total of 374 youth-parent dyads across all participating study sites. Three hundred sixty-eight participants will be included in the analyses. The six other participants are considered “training participants,” who will not be randomized and will receive treatment pathway 1 (all intervention components) for the purpose of providing an opportunity for each interventionist to practice intervention delivery with 1–2 families prior to the enrollment of actual study participants. Power analyses were conducted using FactorialPowerPlan SAS Macro for Aims 1 and 3, and PASS for Aim 2 to determine the appropriate number of participants for the study. The factorial design involves 3 completely crossed factors, and thus the same power calculation applies to each factor being tested, and to interaction effects also, since this is a 23 factorial. Based in part on prior investigations by the study team,1 assumptions include: 5 assessment points (baseline, 6 weeks, 3 months, 6 months, and 12 months), within-subject correlations over time of ρ = 0.6, two-tailed alpha = 0.05, and 10% 12-month attrition were used for all power analyses. In the prior single-site R01 trial, the study team observed 6–12-month HBI treatment effects ranging between 0.26 and 0.32 and PedsQL treatment effects ranging between 0.19 and 0.29. The proposed sample size of 368 (184 per factor present vs. absent comparison) provides power > 0.80 to detect a small effect size of Cohen’s d = 0.15 under these assumptions. In terms of the cell size of the factorial design, we will allocate 46 participants to each of the 8 groups and retain an average of 42 participants within each. In terms of power to detect mediation for Aim 2, with “a” the standardized coefficient between the component group and the mediators = 0.34, “b” the standardized coefficient between the mediators and PedsQL/HBI symptom outcomes = 0.34, and with 368 patients, 10% attrition and alpha set at 5%, the power = 0.80 to detect minimal indirect/mediated effect 0.12 [54]. With a total sample size of 368, the component group by moderator interaction effect size was estimated using ANCOVA with baseline HBI or PedsQL as the covariate. With the probability of a 2-tailed type I error set at 5%, the study will have ≥ 0.80 power to detect a component group by moderator interaction ES = 0.25 for 12-month HBI or PedsQL.

Recruitment

Recruitment will take place from several sources:

Seattle Children’s Hospital: We will recruit from Sports Medicine, Rehabilitation Medicine, Adolescent Medicine, and Neurology clinics as well as the Emergency Department/Urgent Care within Seattle Children’s Hospital. There will be active recruitment by weekly scanning of the appointment lists for these sites. Providers seeing potentially eligible subjects will be contacted prior to patient visits and asked to provide the patient with study information, including a study flyer and/or a recruitment letter with a QR code that they can scan on their phones and will lead them to the CHIP Study REDCap Screening Form. Clinicians will be provided a dot phrase to share with patients if they would like, explaining the CHIP study. If a patient did not receive study information at their visit, we will send them a recruitment letter, briefly explaining the study and options to contact us, and will then text or call them to assess interest (a maximum of 5 additional attempts). Potential participants will also be provided the link to the study website, https://chipstudy.org. Our website will be public and we are able to recruit participants from anywhere in the USA if they come across the study online and meet eligibility requirements.

University of Texas, Southwestern (Dallas, TX): We will recruit from Sports Medicine, Rehabilitation Medicine, and Neurology providers at UTSW and two other organizations associated with UTSW: Children’s Medical Center and Scottish Rite for Children. The UTSW research assistants will approach patients in person and fill out the CHIP REDCap screening form if they are interested. Seattle Children’s research will take over the recruitment process post-screening form.

Assignment of interventions: allocation Sequence generation

Randomization will occur in blocks according to a computer-generated random assignment and stratified by patient’s sex assigned at birth (male or female) and study site (Seattle, UTSW, or other community). Once the randomization spreadsheet is generated, it will be uploaded into the REDCap randomization module.

Concealment mechanism

Once the randomization spreadsheet is generated by the study statistician, it will be uploaded into REDCap. No one will be able to see the allocation sequence until the “randomize” button in REDCap is clicked and the next participant is assigned to a group.

Implementation

Randomization will occur directly in REDCap by the study coordinator. After randomization, a letter and email will be sent to the participant’s family to notify them of which group they have been randomly assigned.

Assignment of interventions: blinding Who will be blinded

Only the study statistician and fidelity coders will be blinded to the treatment pathways. The data will be coded with a number sequence to indicate the treatment pathways. The research coordinators will have access to the data dictionary with the codes.

Procedure for unblinding if needed

Unblinding of the statistician will only occur after data has been analyzed.

Data collection and management Plans for assessment and collection of outcomes

All outcome data will be collected using self-report surveys in REDCap. Surveys will be completed at 6 weeks and 3, 6, and 12 months after enrollment and will be automatically triggered. See the “Primary outcome measures“ section for detailed descriptions of the measurements.

Plans to promote participant retention and complete follow-up

Research coordinators will be tracking survey completion regularly and reaching out to participants with reminders. Our participant incentive will be tied to their survey completion, to encourage participants to complete surveys on time. Additionally, we will send each of our participants a study gift at 3 months to keep them engaged in the follow-up data collection.

Data management

Surveys, video-recorded sessions, and other data will be obtained during the study. Surveys and participant information will be collected and stored in a REDCap project. Video recordings will be stored in a secure Seattle Children’s shared drive.

Confidentiality

All study data will be gathered strictly for research purposes and only accessed by study staff. To ensure subject confidentiality, all research surveys and other research materials will be kept in a locked file cabinet in our secure research space, and all computers used in the collection and storage of data will be password-protected or in a HIPAA-compliant database (REDCap). After data is collected, information that would identify the subjects will be removed and code numbers used instead. A study code will be assigned to each subject. Data stored in REDCap will have PHI variables indicated such that a deidentified dataset could be obtained as needed.

Plans for collection, laboratory evaluation, and storage of biological specimens for genetic or molecular analysis in this trial/future use

N/A, this study does not collect any biologic specimens.