title: Child psychiatric disorder and relative age within school year: cross sectional survey of large population sample.
abstract: OBJECTIVE
  To test the hypothesis that younger children in a school year are at greater risk of emotional and behavioural problems.
  
  
  METHODS
  Cross sectional survey.
  
  
  METHODS
  Community sample from England, Scotland, and Wales.
  
  
  METHODS
  10 438 British 5-15 year olds.
  
  
  METHODS
  Total symptom scores on psychopathology questionnaires completed by parents, teachers, and 11-15 year olds; psychiatric diagnoses based on a clinical review of detailed interview data.
  
  
  RESULTS
  Younger children in a school year were significantly more likely to have higher symptom scores and psychiatric disorder. The adjusted regression coefficients for relative age were 0.51 (95% confidence interval 0.36 to 0.65, P < 0.0001) according to teacher report and 0.35 (0.23 to 0.47, P = 0.0001) for parental report. The adjusted odds ratio for psychiatric diagnoses for decreasing relative age was 1.14 (1.03 to 1.25, P = 0.009). The effect was evident across different measures, raters, and age bands. Cross national comparisons supported a "relative age" explanation based on the disadvantages of immaturity rather than a "season of birth" explanation based on seasonal variation in biological risk.
  
  
  CONCLUSIONS
  The younger children in a school year are at slightly greater psychiatric risk than older children. Increased awareness by teachers of the relative age of their pupils and a more flexible approach to children's progression through school might reduce the number of children with impairing psychiatric disorders in the general population.
authors.affiliation: Department of Child and Adolescent Psychiatry, Institute of Psychiatry, King's College London, London SE5 8AF. r.goodman@iop.kcl.ac.uk
authors.forename: Robert
authors.initials: R
authors.lastname: Goodman
authors.forename: Julia
authors.initials: J
authors.lastname: Gledhill
authors.forename: Tamsin
authors.initials: T
authors.lastname: Ford
mesh_terms: D000293:Adolescent; D000342:Affective Symptoms / Q000453:epidemiology*; D000367:Age Factors; D002648:Child; D002653:Child Behavior Disorders / Q000453:epidemiology*; D002675:Child, Preschool; D003430:Cross-Sectional Studies; D006801:Humans; D015999:Multivariate Analysis; D016017:Odds Ratio; D012307:Risk Factors; D006113:United Kingdom / Q000453:epidemiology