title: Does the Bayley-III Motor Scale at 2 years predict motor outcome at 4 years in very preterm children?
abstract: OBJECTIVE
  To assess the predictive validity of the Bayley Scales of Infant and Toddler Development - Third Edition (Bayley-III) for later motor outcome.
  
  
  METHODS
  Ninety-six infants (49 males, 47 females) born at less than 30 weeks' gestation admitted to two tertiary hospitals in Melbourne, Australia, were assessed with the Bayley-III Motor Scale at 2 years' corrected age and were classified as suspect or definite motor impairment if they scored less than -1 or -2 standard deviations respectively, relative to the test mean. At 4 years' corrected age, children completed Movement Assessment Battery for Children - Second Edition (MABC-2); for the total motor score, cut-offs of not more than the 15th were used to classify motor development and cut-offs of not more than the 15th centile were classified as having a significant movement difficulty.
  
  
  RESULTS
  Of the 96 children assessed at both ages, at 2 years 9% had suspect and 4% had definite motor impairment; however, by 4 years, rates had increased to 22% and 19% respectively. The specificity of the Bayley-III for motor impairments for later motor outcome was excellent (ranging from 94 to 100% for cerebral palsy [CP] and 97 to 100% for motor impairment), although the sensitivity was low (ranging from 67 to 83% for CP and 18 to 37% for motor impairment); many children with later impairment were not identified by the Bayley-III.
  
  
  CONCLUSIONS
  The Bayley-III Motor Scale at 2 years underestimates later rates of motor impairment, particularly in the absence of CP at 4 years on the MABC-2 total motor score in children born at less than 30 weeks' gestational age.
authors.affiliation: Victorian Infant Brain Studies, Murdoch Childrens Research Institute, Melbourne, Australia. alicia.spittle@mcri.edu.au
authors.forename: Alicia J
authors.initials: AJ
authors.lastname: Spittle
authors.forename: Megan M
authors.initials: MM
authors.lastname: Spencer-Smith
authors.forename: Abbey L
authors.initials: AL
authors.lastname: Eeles
authors.forename: Katherine J
authors.initials: KJ
authors.lastname: Lee
authors.forename: Lucy E
authors.initials: LE
authors.lastname: Lorefice
authors.forename: Peter J
authors.initials: PJ
authors.lastname: Anderson
authors.forename: Lex W
authors.initials: LW
authors.lastname: Doyle
mesh_terms: D001315:Australia; D002675:Child, Preschool; D002658:Developmental Disabilities / Q000175:diagnosis* / Q000209:etiology; D005260:Female; D005865:Gestational Age; D006801:Humans; D062071:Infant, Extremely Premature; D008137:Longitudinal Studies; D008297:Male; D009069:Movement Disorders / Q000150:complications / Q000175:diagnosis / Q000209:etiology; D009460:Neurologic Examination / Q000379:methods*; D009483:Neuropsychological Tests; D011237:Predictive Value of Tests; D012680:Sensitivity and Specificity