Pavarin RM, Berardi D, Gambini D. Emergency Department Presentation and Mortality Rate Due to Overdose: A Retrospective Cohort Study on Non-Fatal Overdoses. Subst Abus. 2016 Feb 25:0

BACKGROUND:

The aims of this retrospective cohort study are to describe the presentation characteristics for non-fatal overdose-related complaints at the emergency departments (ED) 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. We used the International Classification of Diseases to ascertain the cause of death.

RESULTS:

We identified 294 episodes of overdose involving 218 individuals. The total time at risk was 1,048 person-years (PY). The mortality rate for all causes was 35.48 per 1,000 PY for males and 20.61 for females. The mortality rate for overdose was 16.6 per 1,000 PY for males and 13.74 for females. In the multivariate regression analysis, the time from first ED overdose access (less than one year RR 7.07 95% CI 5.32-9.39) was significantly associated with death by overdose. Males, subjects aged >30 years at presentation, patients who refused ED treatment and those having previously contacted Mental Health Services (MHSs) showed an increased mortality risk due to overdose.

CONCLUSIONS:

Experiencing a non-fatal overdose within the past 12 months increases the risk of mortality compared to an overdose more than 12 months earlier. Non-fatal overdose patients presenting to an ED form a specific target for prevention projects.