A Peer-Delivered High School Preparatory Intervention for Students With ADHD

Report cards were obtained directly from schools. GPA for each quarter was calculated by converting academic grades (e.g., English, Math, Science, Social Studies) to a 5-point scale (i.e., 4.0=A to 0.0=F). Grades were not weighted for class difficulty.

Number of Class Absences per Academic Quarter

Parent and Teacher Rated ADHD Symptoms on DSM-5 ADHD Checklist, 0=minimum, 3=maximum, Higher score means worse outcome

The Expectancy-Value Theory of Motivation Measure-Student Version (EVTMM) is a gold-standard self-report measure of student motivation with excellent psychometric properties that consists of 11 items measured on a 1-5 scale with higher scores indicating better motivation. The EVTMM's two "importance" items (i.e., "for me being good in school is important" "compared to most of your other activities, how important is it for you to be good in school") were averaged to provide an index of extrinsic motivation. A subscale containing these two items is validated for adolescents. In our sample, alpha for this subscale was .70.

A computerized Iowa gambling task (Hungry Donkey Task) was administered to measure risky decision making (i.e., sensitivity to future negative consequences). Participants were told to assist the hungry donkey to collect as many apples as possible by pressing one of four keys corresponding to four separate doors. The future yield of each door varied, with higher wins at high paying doors (A and B), and lower wins at low paying doors (C and D). Selecting door A or B resulted in a four apple gain, whereas door C or D resulted in a gain of two apples. Number of low-risk doors selected minus number of high-risk doors selected was computed as an index of risky decision making. There is no theoretical maximum/minimum score but negative scores indicate a tendency towards riskier decision making.

Delay discounting was measured using a computerized Choice-Delay Task. Participants were instructed to make repeated choices between a small variable reward (0, 2, 4, 6, 8, or 10 cents) that would be delivered immediately (i.e., after 0 seconds) and a large constant (10 cents) reward that would be delivered after a variable delay of 0, 5, 10, 20, or 30 seconds. After completion of the task, participants received the total earnings from the examiner. Total money earned served as an index of delay discounting with higher amounts of money earned indicating greater tendency to delay rewards and zero as the lower bound and no theoretical maximum. This task shows developmental sensitivity and correlates with ADHD symptoms.

The change ruler is a Motivational Interviewing (MI) scale that assesses various aspects of motivation on 0 to 10 scale using single item scoring and detects adolescent response to ADHD interventions. The extrinsic motivation item asks about how important it is for the adolescent to do well in school. Higher scores indicate higher motivation.

The Expectancy-Value Theory of Motivation Measure-Student Version (EVTMM) is a gold-standard self-report measure of student motivation with excellent psychometric properties that consists of 11 items measured on a 1 to 5 scale with higher values representing higher motivation. The two "interest" items ("in general, I find working on school work interesting…" "How much do you like doing schoolwork?") were averaged to provide an index of intrinsic motivation. The combination of these two items has good reliability and validity. Alpha in our sample was .82.

Delay aversion was measured using the 10-item self-report Quick Delay Questionnaire, which shows good psychometric properties. Individuals self-rate their degree of aversion and response to delayed rewards using a 1 to 5 scale with higher scores indicating higher levels of delay aversion. Alpha for the Quick Delay Questionnaire was .83. items 5-10 are reverse coded.

The Change Ruler is a self-report scale on a 1=minimum value to 10=maximum value scale. The single intrinsic motivation item was used with higher scores indicating higher levels of intrinsic motivation.

The Basic Psychological Needs Scale is a self-report scale with a 1=minimum value 6=maximum value, and higher scores indicating higher levels of intrinsic motivation. The basic psychological needs sense of autonomy sub scale is used by averaging the items on this sub scale.

The goal setting and planning section of the Self-Regulated Learning Interview Schedule (S-RLIS) was converted to a parent-report scale to measure goal setting. Six items measured the extent to which students used goal setting strategies during schoolwork, household tasks, and when unmotivated to complete tasks. Alpha for this measure was .64. An average score was calculated and responses ranged from 0=never to 3=always. Higher scores indicated stronger executive functioning.

The Behavior Rating Index of Executive Function (BRIEF-2) is a well-validated measure of EF behaviors for ages 5-18. Parents rate youth EFs on a three-point scale (0-2) across nine subscales with higher scores indicating poorer EF. BRIEF Metacognition and Behavioral Regulation T-scores were used, which are normed t-scores calculated by the measure's scoring program. Higher T-scores indicate higher levels of impairment. T-Scores have a mean of 50 and a standard deviation of 10. We did not use clinical thresholds and analyzed this measure continuously.

Working memory was measured using the National Institute of Health (NIH) Toolbox List Sorting Working Memory Test. A series of stimuli is presented visually and orally. Participants are instructed to recall stimuli in order of size. The List Sorting task takes ~7 minutes to administer and scores consist of total items correct across all trials with excellent test-retest reliability and convergent and discriminant validity. Normed standardized scores are offered by the scoring program on this task. Higher scores indicate stronger executive functions. The score used is a total Working Memory Standard Score that has a mean of 100 and a standard deviation of 15.

Response inhibition was measured using a go/no-go task with both positively and negatively valenced emotional stimuli. Happy (H) and sad (S) facial expressions were alternated as go and no-go cues across the four blocks in an HSSH order, resulting in equal happy and sad faces serving as cues. A count of the number of commission errors across no-go trials was utilized as a response inhibition measure. The minimum is zero. There is no theoretical maximum. This task shows good convergent validity and is validated with adolescents.

Cognitive flexibility was measured using the NIH Toolbox Dimensional Change Card Sort Test in which a target visual stimulus must be matched to 1 of 2 choice stimuli according to shape or color. The relevant sorting criterion word, "color" or "shape," appears on the screen. An algorithm weights accuracy and reaction time. A total of 40 trials requires 4 minutes. The task shows excellent developmental sensitivity and convergent validity. The measure provides a standardized total norm score with its scoring software. The mean standardized score is 100 and the standard deviation is 15. Higher scores indicate stronger executive functions. There is no theoretical maximum.

Photocopies/screenshots of student planners were obtained at each visit. Planner use during the past week was calculated as the degree to which students recorded homework assignments in a paper planner or digital device. Research assistants counted up the number of classes the student attended during the week. Then they counted up the number of those classes that had homework written down for them in the planner. Percentage of classes with recorded homework (or indication of no homework) was calculated for the last five school days. A total planner use score was calculated as the mean of daily planner use scores. This metric detects response to organization interventions for adolescents with ADHD. Scores can range from 0% to 100% with higher scores indicating greater use of a daily planner.

At each assessment, observations of bookbag organization were obtained using an Organization Checklist (OC; Evans et al., 2009). Research assistants dichotomously scored eight items such as "Is the adolescent's bookbag free from loose papers?" and "Does the adolescent have a folder/binder for each core academic class?" Percentage of OC items achieved were calculated and recorded as a decimal ranging from 0 to 1 (i.e., 20%=0.2.). Maximum score is 1 and minimum is 0. OC scores correlate with teacher impairment ratings and are sensitive to response to organization skills interventions for adolescents with ADHD.

For note-taking, students listened to a 20-minute lecture via video and the percentage of correctly recorded main ideas and supporting details was calculated (Sibley et al., 2018). Four versions of this task were administered reduce practice effects; order was counterbalanced within group. A randomly selected 20% of datapoints were double coded. Intraclass correlation was .98. The score represents the percentage of of correct main ideas and supporting details recorded.

The 24-item parent and teacher Adolescent Academic Problems Checklist (AAPC) measures observable secondary-school specific organization problems and is validated in samples of adolescents with ADHD. Informants rate items from 0-not at all to 3-very much. The AAPC possesses two distinct factors, with strong internal reliability and concurrent validity. The academic skills index was used in this study and with an alpha for this index ranging from .89 to .92. This score represents an average of the items of this subscale. Higher scores indicate greater impairment in executive functions.

Fidelity observers attended each intervention session using standardized fidelity checklists previously implemented in past trials of the STPA or STRIPES interventions. Fidelity ratings measured the reliability and integrity of STRIPES+ implementation. Items were binary and represented each topic that must be covered in the intervention. The score represents a percentage of the total items achieved by the interventionists at each instance of implementing the intervention. For example, the eight item STRIPES fidelity score would get a 100% if all 8 items occurred. The highest checklist score possible is 100% and the lowest is 0%. Higher scores indicate better fidelity. Number of items varies by module of the program. However because they are all converted to a percentage, we can average across them. We double coded 47.1% of STRIPES+ sessions to assess inter-rater reliability on fidelity checklists (intraclass correlation=.90). This measure does not apply to the control group.

number of intervention sessions attended by students. Research assistants kept attendance records for each of the STRIPES components. Only one arm of this study got an intervention so this measure is only relevant to the STRIPES group. The control did not receive intervention.

The Parent Academic Management Scale (PAMS) is a 16-item checklist that measures frequency of parent academic involvement behaviors that include direct oversight and assistance behaviors (e.g., help child organize school materials), contingency management (e.g., use a home academic contract), and home school communication. Parents indicate number of days during the past school week (0 to 5) that they performed each behavior. The PAMS possesses strong psychometric properties as evidenced by good internal consistency, concurrent validity, and predictive validity (Sibley, Campez, et al., 2016). The EF Oversight/Assistance can be calculated by finding the average response value for each subscale item. Alpha for the PAMS subscale was .84.

Treatment credibility was measured from 9th graders and peers using a four-item adaptation of the Client Credibility Questionnaire (CCQ). Respondents rated how logical they found treatment and how confident they were in treatment (0 to 2 scale). Students responded on a 3-point scale. The total score is an average of all items. higher scores indicated better credibility. Only the treatment group received this measure.

Client Credibility Questionnaire which measures intervention credibility, completed by parent, 0=minimum value 8=maximum value, Higher scores mean higher credibility. Only the treatment group fills out this scale.

Ninth graders rated treatment satisfaction post-intervention using a questionnaire developed for ADHD treatments. Respondents rated satisfaction for 20 aspects of orientation and 20 aspects of weekly STRIPES using a Likert 5-point scale for youth (1-5). Higher scores indicated better satisfaction. Mean satisfaction was calculated. In our sample, alpha was from .91. Only the treatment group fills out this questionnaire

The degree to which 9th graders enjoyed working with peers was measured using the seven-item Therapist Bond Scale (TBS). TBS items are rated on a Likert- scale, ranging from 1 (not at all like you) to 4 (very much like you). High scores indicate better bond with the mentor. Psychometric properties are strong for this measure. Alpha was .71 for the TBS in this study. An average score for all items is calculated.