Survival of very preterm (VPT) infants (ie, those born at <32 weeks’ gestation) has improved markedly over recent decades, raising concerns about levels of impairment among survivors.
Numerous studies have been conducted on the association between VPT birth and long-term neurodevelopment and health, and this voluminous literature is increasingly synthesized in systematic reviews with meta-analyses. This methodology is considered to provide the highest level of evidence, but its validity depends on appropriate selection of primary studies and management of heterogeneity. Heterogeneity is pervasive in the literature about VPT birth because of differences in criteria for defining preterm populations, study designs, follow-up periods, follow-up rates, and clinical assessments. Furthermore, medical practices, survival, and morbidities vary markedly across countries and hospitals and can affect long-term prognosis. This study aimed to compare the selection criteria, findings, and heterogeneity of systematic reviews with meta-analyses of cognitive outcomes after VPT birth, which are of major concern in this population and measured in most studies.
Sentenac, M., Boutron, I., Draper, E. S., Kajantie, E., Maier, R. F., Wolke, D., & Zeitlin, J. (2020 – online first). Defining Very Preterm Populations for Systematic Reviews With Meta-analyses. JAMA Pediatrics. doi: http://dx.doi.org/10.1001/jamapediatrics.2020.0956