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CompletedNCT05142826Updated Nov 19, 2025Results posted

Investigation of Strategies to Reduce the Impact of the Relative Age Effect in Kindergarten

An interventional study of Relative Age Effect Intervention and School as Usual in Attention Deficit Hyperactivity Disorder, sponsored by Florida International University. Completed at 1 site in United States. Open to participants aged 4 Years to 5 Years. Per ClinicalTrials.gov, last updated 2025-11-19.

Sponsored by Florida International University · Not applicable, Interventional, and Treatment

Phase
Not applicable
Study type
Interventional
Enrollment
62
Allocation
Randomized
Ages
4 Years to 5 Years
Sex
All
01

Study summary

There is now clear evidence that children entering kindergarten, that are relatively young for the grade (e.g., born in the months immediately preceding the school entry cut-off) are at significantly more risk for receiving an ADHD diagnosis and being prescribed stimulant medication. These risks appear to be related solely to age of entry when other explanatory variables are controlled. This situation, termed the "Relative Age Effect"has potentially serious consequences for kindergarten children (e.g., greater likelihood of being prescribed psychoactive medication to control behavior).

The present proposal aims to develop a teacher intervention to attenuate the impact of the relative age effect on young kindergarteners with elevated ADHD symptoms, and test the correspondence between the hypothesized mechanisms and treatment outcomes related to ADHD (e.g., symptoms, impairment). Following intervention development and refinement, 60 children entering kindergarten in the fall, and young for the grade, will be randomly assigned to (1) Kindergarten as Usual (KAU); (2) a Relative Age Effect prevention intervention administered immediately; or (3) a Relative Age Effect prevention intervention administered mid-year. In the intervention groups, teachers will be introduced to the relative age effect, receive information on how to anchor behavioral ratings in developmental norms, and implement a positive behavioral support to support growth in the child across the kindergarten school year.

Primary aims will be to demonstrate the feasibility and acceptability of the intervention approach as well as the ability of the team to retain young children in a longitudinal trial. Further, the hypothesized mechanisms (e.g., improved neurocognitive functioning; improved teacher use of positive behavioral supports) will be measured and correspondence to hypothesized outcomes (e.g., reduced ADHD symptoms and impairment) will be evaluated. Anticipated benefits include attenuation of any negative effects for children who receive intervention, and risks include breach of confidentiality and worsening of symptoms initially if an intervention is instituted. The knowledge to be gained is important as it could reduce untoward outcomes for the relatively youngest children in the grade.

Read the detailed description

The entry to kindergarten is one of the most memorable and important milestones in a child's school career. Positive and quality kindergarten experiences have been associated with meaningful outcomes sustained into adulthood including greater rates of college attendance/higher earnings. Kindergarten entry is one of the first educational transitions made by a family, and it may cause stress and present new challenges for children and families. Given the increased demands that are associated with school entry and the concerns parents may have about this developmental milestone, there are numerous popular press and policy recommendations (e.g., National Association for the Education of Young Children), as well as empirical papers, that weigh in on the appropriate age to start kindergarten.

The transition to kindergarten is of particular concern for parents of children with ADHD, especially those relatively young for the grade. There is converging evidence suggesting that children who are young for their kindergarten class (e.g., they have a birthdate that falls within the months immediately preceding the cut-off date, typically August through November) are at increased risk for a range of negative educational outcomes including lower academic achievement, grade retention, social impairments, and ADHD diagnosis . These risks appear to be related to age of entry when other explanatory variables are controlled. Thus, these studies suggest that the robust evidence that children closest to an arbitrary cut-off date are disproportionally at-risk for negative social, behavioral, and educational outcomes is solely a consequence of educational policy - a phenomenon called the Relative Age Effect (RAE). Together, the consequence of these risks are 1.5x increased ADHD diagnostic rates and increased ADHD treatment with psychoactive medication for children relatively younger for their kindergarten grade .

There are prominent, candidate mechanisms that may explain the differential risk for children with ADHD who are also young for the grade. First, if a teacher is basing behavioral expectations for children in the classroom based on the relatively older children in the class, children who are relatively younger and have behaviors that are attributed to having considerable delays, even in situations where the child is acting in a manner consistent with their chronological age. Over time, if teachers are issuing frequent commands/reprimands, a coercive process may develop. Second, given expected variability in neurocognitive processing at this age level, inappropriate demands may fail to facilitate, and potentially even slow, the development of executive functions. The present proposal aims to reduce functional impairments and ADHD symptom levels by investigating whether evidence-based school treatment for ADHD (e.g., positive behavior supports) coupled with teacher training on the RAE results in improved school functioning for children with elevated ADHD symptoms prior to the kindergarten year. Further, the potential mechanism for the impairment experienced by children with ADHD will be explored, by investigating whether the impairments are due to characteristics of the child (e.g., deficits in neurocognitive development), the classroom (e.g., teacher classroom management strategies), or both.

02

Conditions studied

  • Attention Deficit Hyperactivity Disorder

Keywords

  • ADHD
  • kindergarten
  • relative age effect
03

In context

Attention Deficit Disorder with Hyperactivity

1,514 studies on the registry are indexed under Attention Deficit Disorder with Hyperactivity; 255 are open to participants now.

This study's enrollment of 62 is below the median of 72 across 1,207 interventional studies indexed under Attention Deficit Disorder with Hyperactivity.

Browse Attention Deficit Disorder with Hyperactivity studies →

Lead sponsor

Florida International University is the lead sponsor of 102 studies on the registry; 18 are open to participants now.

Counted across the registry records on this site, refreshed daily.

04

Who can participate

Ages eligible
4 Years to 5 Years
Sexes eligible
All
Accepts healthy volunteers
No

Inclusion criteria

  • enrolling in Kindergarten
  • has a date of birth 4 months prior to the respective state cut-off for school entry
  • does not have an Individualized Education program for behavioral concerns
  • has not been retained in school or "red-shirted" by parents.

Exclusion criteria

Exclusion Criteria:

  • outside of the targeted birthdate range
  • diagnosed with autism, psychosis, or disruptive mood dysregulation disorder
  • taking psychoactive medication for mood, behavior, or inattention,
  • in a classroom with an already enrolled study participant.
05

Study design

Phase
Not applicable
Primary purpose
Treatment
Allocation
Randomized
Intervention model
Parallel assignment
Masking
Single (Outcomes assessor)
Enrollment
62 participants (actual)

Study arms

  • Active comparator
    School as Usual

    School procedures as typically used and implemented.

    Other: School as Usual

  • Experimental
    Immediate Relative Age Effect Intervention

    Relative age effect intervention administered in the Fall in school.

    Behavioral: Relative Age Effect Intervention

  • Experimental
    Delayed Relative Age Effect Intervention

    Relative age effect intervention administered after the Winter break in school.

    Behavioral: Relative Age Effect Intervention

Interventions

  • BehavioralRelative Age Effect Intervention

    School-based consultation to establish a developmentally appropriate daily behavior report; teacher education regarding developmentally appropriate behaviors; teacher consultation to promote positive behavior supports.

  • OtherSchool as Usual

    Interventions and supports as provided through usual care

06

What researchers measure

Primary outcomes

  1. Disruptive Behavior Disorders Rating Scale

    Average score for ADHD symptom ratings on the Disruptive Behavior Disorders rating scale Average score ranges from 0.0 to 3.0 with higher scores indicating greater impairment.

    Time frame: Baseline (Fall), 3 Months (Winter), 6 Months (Spring) and 12 Months (First Grade Follow-up)

  2. Impairment Rating Scale

    ADHD impairment - teacher rating. Average score ranges from 0.0 to 6.0 with higher scores indicating greater impairment.

    Time frame: Baseline (Fall), 3 Months (Winter), 6 Months (Spring) and 12 Months (First Grade Follow-up)

  3. Student Behavior Teacher Response Observation Code

    Number of disruptive behaviors; higher counts equal the presence of more classroom rule violations

    Time frame: Baseline (Fall), 3 Months (Winter), 6 Months (Spring) and 12 Months (First Grade Follow-up)

  4. Academic Performance Rating Scale

    Teacher rating of academic productivity. Average scores range from 1.0 to 5.0 with lower scores indicating academic underperformance.

    Time frame: Baseline (Fall), 3 Months (Winter), 6 Months (Spring) and 12 Months (First Grade Follow-up)

Other outcomes

  1. Number of Children Who Were Referred to Special Education

    Dichotomous parent rating of yes or no for referral for special education at the end of kindergarten

    Time frame: Collected at the end of the kindergarten school year, approximately 10 months from the start of study procedures.

  2. Number of Children Who Were Prescribed Stimulant Medication

    Dichotomous parent rating of yes or no for initiation of stimulant medication at the end of kindergarten

    Time frame: Collected at the end of the kindergarten school year, approximately 10 months from the start of study procedures.

  3. Number of Children Who Were Retained in Kindergarten

    Dichotomous parent rating of yes or no for retained in kindergarten at the end of kindergarten

    Time frame: Collected at the end of the kindergarten school year, approximately 10 months from the start of study procedures.

07

Results

Posted Nov 19, 2025

Participant flow

Participant flow — Overall Study
MilestoneSchool as UsualImmediate Relative Age Effect InterventionDelayed Relative Age Effect Intervention
Started202121
Completed91614
Not completed1157

Outcome measures

PrimaryDisruptive Behavior Disorders Rating Scale

Average score for ADHD symptom ratings on the Disruptive Behavior Disorders rating scale Average score ranges from 0.0 to 3.0 with higher scores indicating greater impairment.

Time frame:
Baseline (Fall), 3 Months (Winter), 6 Months (Spring) and 12 Months (First Grade Follow-up)
Reported as:
Mean · score on the scale
Disruptive Behavior Disorders Rating Scale
score on the scaleSchool as UsualImmediate Relative Age Effect InterventionDelayed Relative Age Effect Intervention
Baseline Fall Assessment.8 ± .511.12 ± .81.03 ± .72
Winter Assessment1.33 ± .831.15 ± .701.28 ± .85
Spring Assessment1.34 ± .911.13 ± .801.00 ± .65
First Grade Follow-up1.19 ± .581.12 ± .831.05 ± 1.03
PrimaryImpairment Rating Scale

ADHD impairment - teacher rating. Average score ranges from 0.0 to 6.0 with higher scores indicating greater impairment.

Time frame:
Baseline (Fall), 3 Months (Winter), 6 Months (Spring) and 12 Months (First Grade Follow-up)
Reported as:
Mean · Score on the scale
Impairment Rating Scale
Score on the scaleSchool as UsualImmediate Relative Age Effect InterventionDelayed Relative Age Effect Intervention
Fall (Baseline1.48 ± 2.012.25 ± 1.841.84 ± 1.71
Winter2.48 ± 2.152.43 ± 1.431.7 ± 1.66
Spring3.24 ± 2.302.19 ± 1.581.57 ± 1.55
Fall (First Grade Follow-up)2.22 ± 2.402.44 ± 2.061.86 ± 1.94
PrimaryStudent Behavior Teacher Response Observation Code

Number of disruptive behaviors; higher counts equal the presence of more classroom rule violations

Time frame:
Baseline (Fall), 3 Months (Winter), 6 Months (Spring) and 12 Months (First Grade Follow-up)
Reported as:
Mean · Frequency count of behaviors
Student Behavior Teacher Response Observation Code
Frequency count of behaviorsSchool as UsualImmediate Relative Age Effect InterventionDelayed Relative Age Effect Intervention
Fall (Baseline5 ± 4.275.67 ± 6.27 ± 6.7
Winter5.56 ± 8.125.21 ± 7.775.75 ± 4.9
Spring4.22 ± 4.024.36 ± 5.514.17 ± 3.74
First grade follow-up (Fall)3 ± 2.393.88 ± 3.742.6 ± 3.53
PrimaryAcademic Performance Rating Scale

Teacher rating of academic productivity. Average scores range from 1.0 to 5.0 with lower scores indicating academic underperformance.

Time frame:
Baseline (Fall), 3 Months (Winter), 6 Months (Spring) and 12 Months (First Grade Follow-up)
Reported as:
Mean · Score on the scale
Academic Performance Rating Scale
Score on the scaleSchool as UsualImmediate Relative Age Effect InterventionDelayed Relative Age Effect Intervention
Fall (Baseline)3.51 ± .833.22 ± .973.36 ± .97
Winter3.17 ± .553.36 ± .833.34 ± .94
Spring3.15 ± 1.033.5 ± .813.49 ± .84
First Grade Follow-up (Fall)3.7 ± .873.49 ± .83.01 ± 1.09
Other pre-specifiedNumber of Children Who Were Referred to Special Education

Dichotomous parent rating of yes or no for referral for special education at the end of kindergarten

Time frame:
Collected at the end of the kindergarten school year, approximately 10 months from the start of study procedures.
Reported as:
Count of participants · Participants
Number of Children Who Were Referred to Special Education
ParticipantsSchool as UsualImmediate Relative Age Effect InterventionDelayed Relative Age Effect Intervention
Number of Children Who Were Referred to Special Education123
Other pre-specifiedNumber of Children Who Were Prescribed Stimulant Medication

Dichotomous parent rating of yes or no for initiation of stimulant medication at the end of kindergarten

Time frame:
Collected at the end of the kindergarten school year, approximately 10 months from the start of study procedures.
Reported as:
Count of participants · Participants
Number of Children Who Were Prescribed Stimulant Medication
ParticipantsSchool as UsualImmediate Relative Age Effect InterventionDelayed Relative Age Effect Intervention
Number of Children Who Were Prescribed Stimulant Medication002
Other pre-specifiedNumber of Children Who Were Retained in Kindergarten

Dichotomous parent rating of yes or no for retained in kindergarten at the end of kindergarten

Time frame:
Collected at the end of the kindergarten school year, approximately 10 months from the start of study procedures.
Reported as:
Count of participants · Participants
Number of Children Who Were Retained in Kindergarten
ParticipantsSchool as UsualImmediate Relative Age Effect InterventionDelayed Relative Age Effect Intervention
Number of Children Who Were Retained in Kindergarten030

Adverse events

Collected over 1 year, three months. Non-serious events are listed at a 0% frequency threshold.

Adverse event summary by group
GroupDeathsSeriousOther
School as Usual0/20 (0%)0/20 (0%)0/20 (0%)
Immediate Relative Age Effect Intervention0/21 (0%)0/21 (0%)0/21 (0%)
Delayed Relative Age Effect Intervention0/21 (0%)0/21 (0%)0/21 (0%)

Baseline characteristics

Age, Categorical
Age, Categorical(Participants)School as UsualImmediate Relative Age Effect InterventionDelayed Relative Age Effect InterventionTotal
<=18 years20212162
Between 18 and 65 years0000
>=65 years0000
Sex: Female, Male
Sex: Female, Male(Participants)School as UsualImmediate Relative Age Effect InterventionDelayed Relative Age Effect InterventionTotal
Female781328
Male1313834
Race (NIH/OMB)
Race (NIH/OMB)(Participants)School as UsualImmediate Relative Age Effect InterventionDelayed Relative Age Effect InterventionTotal
American Indian or Alaska Native0000
Asian0112
Native Hawaiian or Other Pacific Islander0000
Black or African American23611
White9151034
More than one race1012
Unknown or Not Reported82313
08

Study locations

1 site
  • Center for Children and Families
    Amherst, New York 14226, United States
09

References and documents

Study documents

  • Protocol and statistical analysis plan · Nov 10, 2023

Documents are hosted by the registry — open the source record to download them.

Individual participant data

Plan to share: Yes — De-identified, anonymous data will be shared for the main outcome measures of the Disruptive Behavior Disorders Rating Scale and Impairment Rating Scale

Supporting information: Study protocol, Sap, Icf

10

Updates

Tracking since Sep 25, 2026
No changes since tracking began. The registry record was last updated on Nov 19, 2025, before this site started recording changes on Sep 25, 2026. Its history is on ClinicalTrials.gov ↗
11

Registry details

Key details

Study ID
NCT05142826
Lead sponsor
Florida International University
Collaborators
University at Buffalo, National Institute of Mental Health (NIMH)
Responsible party
Sponsor
First posted
Dec 3, 2021
Start date
Jun 1, 2022
Primary completion
Nov 30, 2024
Completion
Jun 1, 2025
Results posted
Nov 19, 2025
Last update
Nov 19, 2025

Oversight

Data monitoring committee
No
FDA-regulated drug
No
FDA-regulated device
No
View the source record on ClinicalTrials.gov ↗

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