Hansen CS, et al. - A register-based cohort study was performed to describe the prevalence of QTc prolongation among Emergency Department (ED) patients with suspected poisoning as well as to calculate the absolute and relative risk of mortality or cardiac arrest associated with a prolonged QTc interval. This investigation involving all adult first-time contacts with suspected poisoning to the ED of two Swedish hospitals (January 2010–December 2014) and two Danish hospitals (March 2013–April 2014). A prolonged QTc interval in patients arriving with suspected poisoning appeared to be correlated with a threefold increased risk of 30-day all-cause mortality or cardiac arrest in the ED.