Need for Further Analysis in Cognitive Outcomes of Children Born Preterm

To the Editor We read with great interest the well-designed work of “Cognitive Outcomes of Children Born Extremely or Very Preterm Since the 1990s and Associated Risk Factors: A Meta-analysis and Meta-regression” by Twilhaar et al¹ in JAMA Pediatrics. The analysis includes 71 studies comprising 7752 extremely or very preterm children and 5155 control individuals. However, regarding the database retrieval and heterogeneity, we would like to propose the following comments.