title: Correcting for prematurity affects developmental test scores in infants born late and moderately preterm.
abstract: BACKGROUND
  Corrected age is typically applied when assessing the development of children born <32 weeks of gestation. There is no consensus as to whether corrected age should be applied when assessing children born late/moderately preterm (LMPT; 32-36 weeks of gestation).
  
  
  OBJECTIVE
  This study explored the impact of corrected age on developmental test scores in infants born LMPT.
  
  
  METHODS
  221 LMPT infants were assessed at two years corrected age using the Bayley-III cognitive and language scales, from which cognitive and language composite scores were derived (Normative Mean 100; SD 15). Assessments were then re-scored using chronological age. Bayley-III composite scores <80 were used to define developmental delay. Paired sample t-tests were used to assess the difference in mean test scores derived using corrected versus chronological age, and McNemar's tests to assess the difference in the proportion of infants with developmental delay using corrected versus chronological age.
  
  
  RESULTS
  Mean corrected age scores were significantly higher than chronological age scores (cognitive: 2.1 points; 95% CI 1.6, 2.5; language 2.5; 95% CI 2.1, 2.8). Overall, significantly more LMPT infants were classified with developmental delay when chronological (18.3%) versus corrected (15.0%) age was used (p=0.016).
  
  
  CONCLUSIONS
  Correcting for prematurity results in significantly higher developmental test scores and a significantly lower prevalence of developmental delay in LMPT infants and may affect eligibility for intervention services. Researchers and clinicians should be aware that the use of corrected age may impact on developmental test scores at both an individual and population level among infants born LMPT.
authors.affiliation: Department of Health Sciences, University of Leicester, Leicester, UK.
authors.forename: Shalin A
authors.initials: SA
authors.lastname: Parekh
authors.affiliation: Department of Health Sciences, University of Leicester, Leicester, UK.
authors.forename: Elaine M
authors.initials: EM
authors.lastname: Boyle
authors.affiliation: Department of Health Sciences, University of Leicester, Leicester, UK.
authors.forename: Alexa
authors.initials: A
authors.lastname: Guy
authors.affiliation: Department of Health Sciences, University of Leicester, Leicester, UK.
authors.forename: Samarita
authors.initials: S
authors.lastname: Blaggan
authors.affiliation: Department of Health Sciences, University of Leicester, Leicester, UK.
authors.forename: Bradley N
authors.initials: BN
authors.lastname: Manktelow
authors.affiliation: Department of Psychology and Health Sciences Research Institute and Division of Mental Health and Wellbeing, Warwick Medical School, University of Warwick, Coventry, UK.
authors.forename: Dieter
authors.initials: D
authors.lastname: Wolke
authors.affiliation: Department of Health Sciences, University of Leicester, Leicester, UK. Electronic address: sjj19@le.ac.uk.
authors.forename: Samantha
authors.initials: S
authors.lastname: Johnson
mesh_terms: D002657:Child Development; D002658:Developmental Disabilities / Q000175:diagnosis*; D005865:Gestational Age; D006801:Humans; D007231:Infant, Newborn; D007234:Infant, Premature / Q000254:growth & development*; D009460:Neurologic Examination / Q000379:methods / Q000592:standards*
keywords: Corrected age; Developmental assessment; Developmental delay; Neurodevelopmental outcomes; Preterm