Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
Review
. 2023 Mar;37(3):254-262.
doi: 10.1111/ppe.12957. Epub 2023 Feb 6.

Heterogeneity of design features in studies included in systematic reviews with meta-analysis of cognitive outcomes in children born very preterm

Mariane Sentenac  1 , Sabrina Twilhaar  1 , Valérie Benhammou  1 , Andrei S Morgan  1   2 , Samantha Johnson  3 , Anna Chaimani  1 , Jennifer Zeitlin  1
Affiliations
Review

Heterogeneity of design features in studies included in systematic reviews with meta-analysis of cognitive outcomes in children born very preterm

Mariane Sentenac et al. Paediatr Perinat Epidemiol. 2023 Mar.

Abstract

Background: Meta-analyses of the voluminous scientific literature on the impact of very preterm (VPT, <32 weeks' gestation) birth on cognition find a marked deficit in intelligence quotient (IQ) among children born VPT relative to term-born peers, but with unexplained between-study heterogeneity in effect size.

Objectives: To conduct an umbrella review to describe the design and methodology of primary studies and to assess whether methodological heterogeneity affects the results of meta-analyses.

Data sources: Primary studies from five systematic reviews with meta-analysis on VPT birth and childhood IQ.

Study selection and data extraction: Information on study design, sample characteristics and results was extracted from studies. Study features covered study type, sample size, follow-up rates, adjustment for social context, management of severe impairments and test type.

Synthesis: We used random-effects subgroup meta-analyses and meta-regressions to investigate the contribution of study features to between-study variance in standardised mean differences (SMD) in IQ between groups.

Results: In 58 cohorts (56%), children with severe impairments were excluded, while 23 (22%) cohorts accounted for social factors. The least reported feature was the follow-up rate (missing in 38 cohorts). The largest difference in SMDs was between studies using full scale IQ tests (61 cohorts, SMD -0.89, 95% CI -0.96, -0.82) versus short-form tests (27 cohorts, SMD -0.68, 95% CI -0.79, -0.57). The proportion of between-study variance explained by the type of test was 14%; the other features explained less than 1% of the variance.

Conclusions: Study design and methodology varied across studies, but most of them did not affect the variance in effect size, except the type of cognitive test. Key features, such as the follow-up rate, were not consistently reported limiting the evaluation of their potential contribution. Incomplete reporting limited the evaluation of the full impact of this methodological diversity.

Keywords: cognition; heterogeneity; meta-analysis; preterm infants; very low birthweight.

PubMed Disclaimer

References

REFERENCES

    1. Allotey J, Zamora J, Cheong-See F, et al. Cognitive, motor, behavioural and academic performances of children born preterm: a meta-analysis and systematic review involving 64 061 children. BJOG. 2018;125:16-25.
    1. Brydges CR, Landes JK, Reid CL, Campbell C, French N, Anderson M. Cognitive outcomes in children and adolescents born very preterm: a meta-analysis. Dev Med Child Neurol. 2018;60:452-468.
    1. Twilhaar E, Wade RM, de Kieviet JF, van Goudoever JB, van Elburg RM, Oosterlaan J. Cognitive outcomes of children born extremely or very preterm since the 1990 s and associated risk factors: a meta-analysis and meta-regression. JAMA Pediatrics. 2018;172:361-367.
    1. Arpi E, D'Amico R, Lucaccioni L, Bedetti L, Berardi A, Ferrari F. Worse global intellectual and worse neuropsychological functioning in preterm-born children at preschool age: a meta-analysis. Acta Paediatr. 2019;108:1567-1579.
    1. Linsell L, Malouf R, Morris J, Kurinczuk JJ, Marlow N. Prognostic factors for poor cognitive development in children born very preterm or with very low birth weight: a systematic review. JAMA Pediatr. 2015;169:1162-1172.

Publication types

LinkOut - more resources