Meta-analysis of neurobehavioral outcomes in very preterm and/or very low birth weight children.
OBJECTIVE
Sequelae of academic underachievement, behavioral problems, and poor executive function (EF) have been extensively reported for very preterm (<or=33 weeks' gestation) and/or very low birth weight (VLBW) (<or=1500 g) children. Great variability in the published results, however, hinders the field in studying underlying dysfunctions and developing intervention strategies. We conducted a quantitative meta-analysis of studies published between 1998 and 2008 on academic achievement, behavioral functioning, and EF with the aim of providing aggregated measures of effect size for these outcome domains.


METHODS
Suitable for inclusion were 14 studies on academic achievement, 9 studies on behavioral problems, and 12 studies on EF, which compared a total of 4125 very preterm and/or VLBW children with 3197 term-born controls. Combined effect sizes for the 3 outcome domains were calculated in terms of Cohen's d. Q-test statistics were performed to test homogeneity among the obtained effect sizes. Pearson's correlation coefficients were calculated to examine the impact of mean birth weight and mean gestational age, as well as the influence of mean age at assessment on the effect sizes for academic achievement, behavioral problems, and EF.


RESULTS
Combined effect sizes show that very preterm and/or VLBW children score 0.60 SD lower on mathematics tests, 0.48 SD on reading tests, and 0.76 SD on spelling tests than term-born peers. Of all behavioral problems stacked, attention problems were most pronounced in very preterm and/or VLBW children, with teacher and parent ratings being 0.43 to 0.59 SD higher than for controls, respectively. Combined effect sizes for parent and teacher ratings of internalizing behavior problems were small (<0.28) and for externalizing behavior problems negligible (<0.09) and not significant. Combined effect sizes for EF revealed a decrement of 0.57 SD for verbal fluency, 0.36 SD for working memory, and 0.49 SD for cognitive flexibility in comparison to controls. Mean age at assessment was not correlated with the strength of the effect sizes. Mathematics and reading performance, parent ratings of internalizing problems, teacher ratings of externalizing behavior, and attention problems, showed strong and positive correlations with mean birth weight and mean gestational age (all r values > 0.51).


CONCLUSIONS
Very preterm and/or VLBW children have moderate-to-severe deficits in academic achievement, attention problems, and internalizing behavioral problems and poor EF, which are adverse outcomes that were strongly correlated to their immaturity at birth. During transition to young adulthood these children continue to lag behind term-born peers.
Aarnoudse-Moens
Cornelieke Sandrine Hanan
CS
Division of Neonatology, Department of Pediatrics, Erasmus University Medical Centre Sophia Children's Hospital, Rotterdam, Netherlands. c.moens@erasmusmc.nl
Weisglas-Kuperus
Nynke
N
van Goudoever
Johannes Bernard
JB
Oosterlaan
Jaap
J
D000124:Achievement; D000293:Adolescent; D001289:Attention Deficit Disorder with Hyperactivity / Q000175:diagnosis / Q000453:epidemiology; D001925:Brain Damage, Chronic / Q000175:diagnosis* / Q000453:epidemiology; D002648:Child; D002653:Child Behavior Disorders / Q000175:diagnosis* / Q000453:epidemiology; D002675:Child, Preschool; D003072:Cognition Disorders / Q000175:diagnosis* / Q000453:epidemiology; D003430:Cross-Sectional Studies; D002658:Developmental Disabilities / Q000175:diagnosis* / Q000453:epidemiology; D005865:Gestational Age; D006801:Humans; D007223:Infant; D052577:Infant, Extremely Low Birth Weight; D007231:Infant, Newborn; D007235:Infant, Premature, Diseases / Q000175:diagnosis* / Q000453:epidemiology; D019102:Infant, Very Low Birth Weight; D007389:Internal-External Control; D007859:Learning Disabilities / Q000175:diagnosis* / Q000453:epidemiology; D008137:Longitudinal Studies; D009460:Neurologic Examination / Q000706:statistics & numerical data; D009483:Neuropsychological Tests / Q000706:statistics & numerical data; D011594:Psychometrics / Q000706:statistics & numerical data; D012016:Reference Values; D012307:Risk Factors; D013223:Statistics as Topic