The target population for this study will be children between the ages of 6-12 with a
diagnosis of ADHD, ASD or CHD. Potential subjects for this study will be recruited from
the clinical teams within SickKids and partnering institutions (e.g., CAMH and Holland
Bloorview). Participants will be identified by a psychiatrist, psychologist or specialist
physician as meeting diagnostic criteria for one of the three disorders; 1) ADHD, 2) ASD,
3) CHD. Families of children who have expressed interested in this study will be
contacted by research staff to discuss the study in more detail and will coordinate the
logistics of an initial consent and enrollment appointment. Parent(s)/guardian(s) of
participants will be required to consent and children will be required to assent to take
in this study.
This protocol is divided into 3 studies: sub-study 1 (ADHD), sub-study 2 (ASD) and
sub-study 3 (CHD) each consisting of a pre-post treatment design with 6 month follow-up.
Each sub-study includes an active treatment and wait -list arm. Please see study visit
schedule (pg. 11) for time-line of events and measures by participant at each time point.
Participants will be tested at SickKids at pre-treatment, post-treatment and follow-up.
Participants will train at home with weekly calls from research staff. Assessors at all
clinic visits will be blind to treatment status. All pre, post and following-up clinic
assessments will be conducted off stimulant medication with a washout period of 48 hours.
Stratification: Participants may be taking medications at the time of the study
(stimulants and non-stimulants including SSRI or antipsychotic medications). Families
will be asked to be stabilized on their current dose of medication for at least for a
month before commencing the study and to maintain the same medication and dosage during
the 5 week study. If a change in the type of medication or dosage takes place during the
study it will be recorded. Due to the established impact of stimulant medications on EF
20 21 this class of medication will be used as part of the randomization process to
attain equal proportions of participants using stimulant medications in the Mega Team and
TAU groups. As some medication use is anticipated in all disorder groups the same
randomization approach will be used in all three studies.
Sample Size: The sample size for sub-study 1 (ADHD) will be 220 participants with 110
randomized into each group from initial estimated recruitment pool of 250. The sample
size will provide 80% power to declare statistical significance if the true difference
between treatment groups is 0.43 standard deviations or greater, using a two-sided, 5%
level test of hypothesis, Bonferroni corrected for three comparisons. A pilot study of
Mega Team is currently underway (Dr. Crosbie PI, a registered clinical trial) and results
from that pilot will provide final estimates of the standard deviations before
commencement of the current study. The planned sample for each of sub-study 2 (ASD) and
sub-study 3 (CHD) will be 120 (60 per arm) given the novelty of investigating cognitive
rehabilitation targeting EFs in these populations. Information from sub-study 1, which
will happen first, and the results from the Mega Team pilot study, will allow adjustment
in sample size of sub-study 2 and sub-study 3. All aspects of enrollment, randomization,
and attrition will be monitored and documents using CONSORT flow diagram22.
Randomization: Participants within each sub-study who have consented/ assented to the
study and meet all inclusion criterion will be randomized to either Mega Team or TAU
waitlist stratified by medication status (yes or no)) using random block sizes.
Randomization will be carried out using RedCAP23.
Blinding: Assessors at all clinic visits will be blind to treatment status. Participants
and parents will be asked not to make mention of their treatment status during visits.
They will be reminded of this regularly. Assessors will indicate their blinded status at
the end of all visits. Parents and children will be asked not to inform teachers of the
treatment status. At the time of questionnaire completion, teachers will be asked if they
are aware of the treatment status of the child.
Intervention Conditions:
Mega Team Training Sessions: Mega Team is highly engaging video game based cognitive
intervention that trains multiple executive functions: response inhibition, verbal
working memory and visual working memory in the context of a single game with increasing
difficulty based on the individual performance. Children in the treatment group will
train at home on their own tablet or on a study tablet provided to the family (if
needed). They will be instructed to practice Mega Team for 15 minutes a day,
approximately 5 days a week for a targeted minimum of 21 sessions and a maximum of 25
sessions. The minimum value of 21 sessions has been selected based on findings of prior
research. Majority of studies using other models of intervention have been able to
capture significant training-induced improvements after 21 sessions 24-26. The maximum
training of 25 sessions has been set to control for variability within and between our
groups. Performance on Mega Team will automatically upload to a secure portal hosted by
eHave for monitoring of enrolment, adherence and for data analyses. Scoring algorithms
will track how often and how long the participants trained on Mega Team as well as their
performance. Weekly calls from research staff will provide motivation and address
barriers to game play.
TAU waiting list Control: Children in the control group will not be provided with any
overt intervention but continue with treatment recommendations as provided by their
clinical care team. They will be asked to complete a video game usage log weekly to
record the type and duration of their regular video game playing, and will receive weekly
calls from research staff, as will participants assigned to Mega Team. Participants on in
the TAU group will be given access to the game at the completion of the 6 month follow-up
visit.
