title: Factors affecting vocabulary acquisition at age 2 in children born between 23 and 28 weeks' gestation.
abstract: Language development is often slower in preterm children compared with their term peers. We investigated factors associated with vocabulary acquisition at 2 years in a cohort of children born at 28 weeks' gestation or less. For children entered into the United Kingdom Oscillation Study, language development was evaluated by using the MacArthur-Bates Communicative Development Inventories score, completed by parents as part of a developmental questionnaire. The effect of demographic, neonatal, socioeconomic factors, growth, and disability were investigated using multifactorial random effects modelling. Questionnaires were returned by 288 participants (148 males, 140 females). The mean number of words vocalized was 42 (SD 29). Multifactorial analysis showed only four factors were significantly associated with vocabulary acquisition. These were: (1) level of disability (mean words: no disability, 45; other disability, 38; severe disability, 30 [severe disability is defined as at least one extreme response in one of the following clinical domains: neuromotor, vision, hearing, communication, or other physical disabilities]; 95% confidence interval [CI] for the difference between no and severe disability 7- 23); (2) sex (39 males, 44 females; 95% CI 0.4-11); (3) length of hospital stay (lower quartile, 47; upper quartile, 38; 95% CI -12 to -4); and (4) weight SD score at 12 months (lower quartile, 39; upper quartile, 44; 95% CI 1-9). There was no significant association between gestational age and vocabulary after multifactorial analysis. There was no significant effect of any socioeconomic factor on vocabulary acquisition. We conclude that clinical factors, particularly indicators of severe morbidity, dominate the correlates of vocabulary acquisition at age 2 in children born very preterm.
authors.affiliation: School of Health Sciences and Social Care, Brunel University, Uxbridge, UK. Louise.Marston@brunel.ac.uk
authors.forename: Louise
authors.initials: L
authors.lastname: Marston
authors.forename: Janet L
authors.initials: JL
authors.lastname: Peacock
authors.forename: Sandra A
authors.initials: SA
authors.lastname: Calvert
authors.forename: Anne
authors.initials: A
authors.lastname: Greenough
authors.forename: Neil
authors.initials: N
authors.lastname: Marlow
mesh_terms: D002675:Child, Preschool; D015331:Cohort Studies; D016001:Confidence Intervals; D004185:Disability Evaluation; D005260:Female; D006801:Humans; D007804:Language Development; D007902:Length of Stay; D008297:Male; D015999:Multivariate Analysis; D047928:Premature Birth / Q000503:physiopathology*; D011795:Surveys and Questionnaires; D014706:Verbal Learning / Q000502:physiology*