van Noort–van der Spek IL et al. – While growing up, preterm–born children have increasing difficulties with complex language function.Methods
- Computerized databases Embase, PubMed, Web of Knowledge, and PsycInfo were searched for studies published between January 1995 and March 2011 reporting language functions in preterm-born children.
- Outcome measures were simple language function assessed by using the Peabody Picture Vocabulary Test and complex language function assessed by using the Clinical Evaluation of Language Fundamentals.
- Pooled effect sizes (in terms of Cohen’s d) and 95% confidence intervals (CI) for simple and complex language functions were calculated by using random-effects models.
- Meta-regression was conducted with mean difference of effect size as the outcome variable and assessment age as the explanatory variable.
- Preterm-born children scored significantly lower compared with term-born children on simple (d = –0.45 [95% CI: –0.59 to –0.30]; P < .001) and on complex (d = –0.62 [95% CI: –0.82 to –0.43]; P < .001) language function tests, even in the absence of major disabilities and independent of social economic status.
- For complex language function (but not for simple language function), group differences between preterm- and term-born children increased significantly from 3 to 12 years of age (slope = –0.05; P = .03).