Emergency department presentation and mortality rate due to overdose: A retrospective cohort study on nonfatal overdoses.

Background: The aims of this retrospective cohort study are to describe the presentation characteristics for nonfatal overdose-related complaints at the emergency departments (EDs) of the metropolitan area of Bologna (northern Italy), to estimate the subsequent risk of mortality by overdose, and to identify the profiles of the subjects most at risk.

Methods: Records of patients admitted to 10 EDs for overdose between January 2004 and December 2012 were retrospectively evaluated. The International Classification of Diseases was used to ascertain the cause of death.