Effect of Correcting the Postnatal Age of Preterm-Born Children on Measures of Associations Between Infant Length-for-Age z-Scores and Mid-Childhood Outcomes.

Effect of Correcting the Postnatal Age of Preterm-Born Children on Measures of Associations Between Infant Length-for-Age z-Scores and Mid-Childhood Outcomes.
Am J Epidemiol. 2020 Aug 18;:
Authors: Perumal N, Roth DE, Cole DC, Zlotkin SH, Perdrizet J, Barros AJD, Santos IS, Matijasevich A, Bassani DG
Abstract
Child growth standards are commonly used to derive age- and sex-standardized anthropometric indices, but are often inappropriately applied to preterm-born children (<37 weeks of gestational age (GA)) in epidemiology studies. Using the 2004 Pelotas Birth Cohort, we examined the impact of correcting for GA in the application of child growth standards on the magnitude and direction of associations in two a priori selected exposure-outcome scenarios: infant length-for-age z score (LAZ) and mid-childhood body mass index (scenario A), and infant LAZ and mid-childhood intelligence quotient (scenario B). GA was a confounder that had a strong (scenario A) or weak (scenario B) association with the outcome. Compared to uncorrected postnatal age, using GA-corrected postnatal age attenuated the magnitude of associations, particularly in early infancy, and changed inferences for associations at birth. Although differences in the magnitude of associations were small when GA was weakly associated with the outcome, model fit was meaningfully improved using corrected postnatal age. When estimating population-averaged associations with early ch...

Source: Am J Epidemiol - August 17, 2020 Category: Epidemiology Authors: Perumal N, Roth DE, Cole DC, Zlotkin SH, Perdrizet J, Barros AJD, Santos IS, Matijasevich A, Bassani DG Tags: Am J Epidemiol Source Type: research