Cognitive functioning at the age of 10 years among children born extremely preterm: a latent profile approach

Abstract

BackgroundSchool-age children born extremely preterm (EP) are more likely than their term peers to have multiple neurocognitive limitations. We identify subgroups of EP children who share similar profiles on measures of intelligence quotient (IQ) and executive function (EF), and describe the nature and prevalence of cognitive impairment in EP children.MethodsOn the basis of measures of IQ and EF, subgroups of EP children with common neurocognitive function are identified using latent profile analysis (LPA). On the basis of these subgroups, we describe the nature and prevalence of impairment in EP children, and examine associations between cognitive function, gestational age, and academic achievement. Classification of neurocognitive function using IQ and EF is compared with a standard classification based on IQ Z-scores.ResultsLPA identified four neurocognitive profiles in EP children, with 34% of EP children classified as normal, 41% low-normal, 17% moderately impaired, and 8% severely impaired. Impaired children exhibited global impairment across cognitive domains, whereas children in the low-normal group tended to have impaired inhibition relative to their reasoning and working memory skills.ConclusionWithin categories of EP children defined in terms of IQ, there is substantial variation in EF; thus, both IQ and EF assessments are needed when describing school-age outcome of EP children.

Figure 1

Means of cognitive ability measures (in standard deviations from the norm) for the four LPA classes. Bars represent 95% confidence interval around the mean. VIQ – DAS-II Verbal Reasoning, NIQ – DAS-II Nonverbal Reasoning, SqB – DAS-II Recall of Digits Backward, SqO – DAS-II Recall of Sequential Order, AnS – NEPSY-II Animal Sorting, AA - NEPSY-II Auditory Attention, RS - NEPSY-II Response Set, InI - NEPSY-II Inhibition-Inhibition, InS - NEPSY-II Inhibition-Switching