To the Editor Bhanji et al1 found that in-hospital mortality of pediatric patients undergoing cardiopulmonary resuscitation for cardiac arrest was lower during the day/evening than at night. They suggest a causal effect may be at play, possibly mediated by lower staffing at night, and make efforts to estimate the day/night risk contrast in exchangeable populations. Unfortunately, important sources of potential bias were left unaddressed. Here, we request extra steps to accommodate likely confounders.
Parra CO, Nyanchoka L, Goetghebeur E. Different Pediatric Survival After Cardiac Arrest. JAMA Pediatr. Published online May 08, 2017. doi:10.1001/jamapediatrics.2017.0860