To the Editor We read with interest the study by Morriss et al1 and the accompanying editorial recently published in JAMA Pediatrics.2 We applaud their use of a propensity score modeling approach to answer the following question facing neonatologists and surgeons: is it the surgery or the underlying condition/status of the infant that is associated with neurodevelopmental impairment? However, we wish to highlight an important shortcoming in the authors’ attempt to reduce bias owing to confounding by indication.
Weisz DE, Mirea L, Shah PS. Surgery and Neurodevelopmental ImpairmentNeed for Time-Dependent Covariates to Correct for Confounding by Indication. JAMA Pediatr. 2014;168(12):1168-1169. doi:10.1001/jamapediatrics.2014.1781