title: Continuous admission to primary school and mental health problems.
abstract: BACKGROUND
  Younger children in a school class have higher rates of mental health problems if admission to primary school occurs once a year. This study examines whether this relative age effect also occurs if children are admitted to school continuously throughout the year.
  
  
  METHODS
  We assessed mental health problems based on parent-reports (using the Child Behavior Checklist, CBCL) and on professional assessments, among two Dutch national samples of in total 12,221 children aged 5-15 years (response rate: 86.9%).
  
  
  RESULTS
  At ages 5-6, we found a higher occurrence of mental health problems in relatively young children, both for mean CBCL scores (p = 0.017) and for problems assessed by child health professionals (p < 0.0001). At ages 7-15, differences by relative age did not reach statistical significance.
  
  
  CONCLUSIONS
  Continuous admission to primary school does not prevent mental health problems among young children, but may do so at older ages. Its potential for the prevention of mental problems deserves further study.
authors.affiliation: University Medical Center Groningen, University of Groningen, Department of Health Sciences, P,O, Box 196, 9700 AD Groningen, The Netherlands. s.a.reijneveld@med.umcg.nl
authors.forename: Sijmen A
authors.initials: SA
authors.lastname: Reijneveld
authors.forename: Carin H
authors.initials: CH
authors.lastname: Wiefferink
authors.forename: Emily
authors.initials: E
authors.lastname: Brugman
authors.forename: Frank C
authors.initials: FC
authors.lastname: Verhulst
authors.forename: S Pauline
authors.initials: SP
authors.lastname: Verloove-Vanhorick
authors.forename: Theo G W
authors.initials: TG
authors.lastname: Paulussen
mesh_terms: D000293:Adolescent; D000367:Age Factors; D002648:Child; D002653:Child Behavior Disorders / Q000453:epidemiology / Q000517:prevention & control; D002669:Child Welfare / Q000706:statistics & numerical data*; D002675:Child, Preschool; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D008297:Male; D001523:Mental Disorders / Q000453:epidemiology* / Q000517:prevention & control; D009426:Netherlands / Q000453:epidemiology; D015995:Prevalence; D011640:Public Policy; D012307:Risk Factors; D012570:School Admission Criteria; D012574:Schools / Q000331:legislation & jurisprudence*; D013997:Time Factors