TY - JOUR
T1 - Association between relative age at school and persistence of ADHD in prospective studies
T2 - an individual participant data meta-analysis
AU - Synergy for the Influence of the Month of Birth in ADHD (SIMBA) study group
AU - Gosling, Corentin J.
AU - Caparos, Serge
AU - Pinabiaux, Charlotte
AU - Schwarzer, Guido
AU - Rücker, Gerta
AU - Agha, Sharifah S.
AU - Alrouh, Hekmat
AU - Ambler, Antony
AU - Anderson, Peter
AU - Andiarena, Ainara
AU - Arnold, L. Eugene
AU - Arseneault, Louise
AU - Asherson, Philip
AU - Babinski, Leslie
AU - Barbati, Vittoria
AU - Barkley, Russel
AU - Barros, Aluisio J.D.
AU - Barros, Fernando
AU - Bates, John E.
AU - Bell, Laura J.
AU - Berenguer, Carmen
AU - van Bergen, Elsje
AU - Biederman, Joseph
AU - Birmaher, Boris
AU - B⊘e, Tormod
AU - Boomsma, Dorret I.
AU - Brandt, Valerie C.
AU - Bressan, Rodrigo A.
AU - Brocki, Karin
AU - Broughton, Thomas R.
AU - Bufferd, Sara J.
AU - Bussing, Regina
AU - Cao, Meng
AU - Cartigny, Ariane
AU - Casas, Ana Miranda
AU - Caspi, Avshalom
AU - Castellanos, F. Xavier
AU - Caye, Arthur
AU - Cederkvist, Luise
AU - Collishaw, Stephan
AU - Copeland, William E.
AU - Cote, Sylvana M.
AU - Coventry, William L.
AU - Debes, Nanette M.M.Mol
AU - Denyer, Hayley
AU - Dodge, Kenneth A.
AU - Groenman, Annabeth P.
AU - Hartman, Catharina A.
AU - Klein, Daniel N.
AU - Vos, Melissa
AU - Solmi, Marco
AU - Delorme, Richard
AU - Cortese, Samuele
N1 - Publisher Copyright:
© 2023 The Authors. Published by Elsevier Ltd. This is an Open Access article under the CC BY 4.0 license
PY - 2023/12
Y1 - 2023/12
N2 - Background: The youngest children in a school class are more likely than the oldest to be diagnosed with ADHD, but this relative age effect is less frequent in older than in younger school-grade children. However, no study has explored the association between relative age and the persistence of ADHD diagnosis at older ages. We aimed to quantify the association between relative age and persistence of ADHD at older ages. Methods: For this meta-analysis, we searched MEDLINE, Embase, CINAHL, PsycINFO, and PubPsych up to April 1, 2022, with terms related to “cohort” and “ADHD” with no date, publication type, or language restrictions. We gathered individual participant data from prospective cohorts that included at least ten children identified with ADHD before age 10 years. ADHD was defined by either a clinical diagnosis or symptoms exceeding clinical cutoffs. Relative age was recorded as the month of birth in relation to the school-entry cutoff date. Study authors were invited to share raw data or to apply a script to analyse data locally and generate anonymised results. Our outcome was ADHD status at a diagnostic reassessment, conducted at least 4 years after the initial assessment and after age 10 years. No information on sex, gender, or ethnicity was collected. We did a two-stage random-effects individual participant data meta-analysis to assess the association of relative age with persistence of ADHD at follow-up. This study was registered with PROSPERO, CRD42020212650. Findings: Of 33 119 studies generated by our search, we identified 130 eligible unique studies and were able to gather individual participant data from 57 prospective studies following up 6504 children with ADHD. After exclusion of 16 studies in regions with a flexible school entry system that did not allow confident linkage of birthdate to relative age, the primary analysis included 41 studies in 15 countries following up 4708 children for a period of 4 to 33 years. We found that younger relative age was not statistically significantly associated with ADHD persistence at follow-up (odds ratio 1·02, 95% CI 0·99–1·06; p=0·19). We observed statistically significant heterogeneity in our model (Q=75·82, p=0·0011, I2=45%). Participant-level sensitivity analyses showed similar results in cohorts with a robust relative age effect at baseline and when restricting to cohorts involving children with a clinical diagnosis of ADHD or with a follow-up duration of more than 10 years. Interpretation: The diagnosis of ADHD in younger children in a class is no more likely to be disconfirmed over time than that of older children in the class. One interpretation is that the relative age effect decreases the likelihood of children of older relative age receiving a diagnosis of ADHD, and another is that assigning a diagnostic label of ADHD leads to unexplored carryover effects of the initial diagnosis that persist over time. Future studies should be conducted to explore these interpretations further. Funding: None.
AB - Background: The youngest children in a school class are more likely than the oldest to be diagnosed with ADHD, but this relative age effect is less frequent in older than in younger school-grade children. However, no study has explored the association between relative age and the persistence of ADHD diagnosis at older ages. We aimed to quantify the association between relative age and persistence of ADHD at older ages. Methods: For this meta-analysis, we searched MEDLINE, Embase, CINAHL, PsycINFO, and PubPsych up to April 1, 2022, with terms related to “cohort” and “ADHD” with no date, publication type, or language restrictions. We gathered individual participant data from prospective cohorts that included at least ten children identified with ADHD before age 10 years. ADHD was defined by either a clinical diagnosis or symptoms exceeding clinical cutoffs. Relative age was recorded as the month of birth in relation to the school-entry cutoff date. Study authors were invited to share raw data or to apply a script to analyse data locally and generate anonymised results. Our outcome was ADHD status at a diagnostic reassessment, conducted at least 4 years after the initial assessment and after age 10 years. No information on sex, gender, or ethnicity was collected. We did a two-stage random-effects individual participant data meta-analysis to assess the association of relative age with persistence of ADHD at follow-up. This study was registered with PROSPERO, CRD42020212650. Findings: Of 33 119 studies generated by our search, we identified 130 eligible unique studies and were able to gather individual participant data from 57 prospective studies following up 6504 children with ADHD. After exclusion of 16 studies in regions with a flexible school entry system that did not allow confident linkage of birthdate to relative age, the primary analysis included 41 studies in 15 countries following up 4708 children for a period of 4 to 33 years. We found that younger relative age was not statistically significantly associated with ADHD persistence at follow-up (odds ratio 1·02, 95% CI 0·99–1·06; p=0·19). We observed statistically significant heterogeneity in our model (Q=75·82, p=0·0011, I2=45%). Participant-level sensitivity analyses showed similar results in cohorts with a robust relative age effect at baseline and when restricting to cohorts involving children with a clinical diagnosis of ADHD or with a follow-up duration of more than 10 years. Interpretation: The diagnosis of ADHD in younger children in a class is no more likely to be disconfirmed over time than that of older children in the class. One interpretation is that the relative age effect decreases the likelihood of children of older relative age receiving a diagnosis of ADHD, and another is that assigning a diagnostic label of ADHD leads to unexplored carryover effects of the initial diagnosis that persist over time. Future studies should be conducted to explore these interpretations further. Funding: None.
UR - http://www.scopus.com/inward/record.url?scp=85174799624&partnerID=8YFLogxK
U2 - 10.1016/S2215-0366(23)00272-9
DO - 10.1016/S2215-0366(23)00272-9
M3 - Article
C2 - 37898142
AN - SCOPUS:85174799624
SN - 2215-0366
VL - 10
SP - 922
EP - 933
JO - The Lancet Psychiatry
JF - The Lancet Psychiatry
IS - 12
ER -