Characteristics and outcomes of critically ill patients with drug overdose in Australia and New Zealand.

OBJECTIVE: The epidemiology of patients admitted to the intensive care unit after a drug overdose (OD) is poorly defined. We aimed to study the incidence, characteristics and outcomes of patients admitted to the ICU because of OD in Australia and New Zealand.

DESIGN, SETTING AND PATIENTS: Retrospective study of data from the Australian and New Zealand Intensive Care Society Adult Patient Database, including all patients admitted to an ICU with OD from 2005 to 2013.

RESULTS: Overall, of 883 618 patients treated in the ICU during the study period, 18 050 (2.04%) were admitted because of OD. Over nearly a decade, the proportion of ICU admissions secondary to OD increased significantly from 1.3% in 2005 to 2.4% in 2013 (P < 0.0001). The annual incidence of ODrelated admissions increased from 63 per million people in 2005 to 166 per million in 2013 (P < 0.0001). The largest increase was noted among Indigenous Australians, from 31 per million in 2005 to 436 per million in 2013, with a peak incidence in 2012 of 553 per million (P = 0.0006). Most patients were female (56.4%) and the mean age was 40.2 years (SD, 15.4 years). Overall, ICU and hospital mortality rates were low, at 1.3% and 1.7%, respectively, and did not change over time. Non-survivors were significantly older than survivors and had higher rates of organ failure, intubation and cardiac arrest at presentation, more chronic comorbidities and higher illness severity scores.

CONCLUSIONS: Drug OD accounts for an increasing proportion of ICU admissions in Australia and New Zealand. Its population incidence is increasing overall, particularly in Indigenous Australians.