Effects of Correcting for Prematurity on Executive Function Scores of Children Born Very Preterm at School Age.

OBJECTIVE

To investigate whether correction for prematurity affects executive function scores in school-aged children born very preterm.

STUDY DESIGN

Executive functions were assessed with standardized neuropsychological tests in 142 children born very preterm (born at ≤32 weeks of gestational age or with a birth weight of ≤1500 g) and 391 control children, aged 7-13 years. Four-month age bands were established from the data of control children. Differences between uncorrected and corrected scores were compared against zero difference and between very preterm children born before and after 28 weeks of gestation. Regression models were used to compare the uncorrected and corrected scores of children born very preterm with control children.

RESULTS

For all executive functions, significant, larger-than-zero differences between uncorrected and corrected scores were apparent in children born very preterm. Mean differences ranged from 0.04 to 0.18 SDs. Weak evidence was found that the effect of age correction is more pronounced in very preterm children born before 28 weeks of gestation than in those born after 28 weeks. Differences in executive function scores between children born very preterm and control children were attenuated if scores were corrected for prematurity.

CONCLUSIONS

Test scores based on corrected rather than uncorrected age may more accurately determine the developmental stage of very preterm children's executive functions at school age. Potential consequences for clinical and research practice need to be discussed in the future.