Fatalities and hospitalisations due to acute poisoning among New Zealand adults

Background: Acute poisoning accounts for a significant proportion of the total burden of disease worldwide. While the rate of poisoning fatalities in New Zealand is comparable to other industrialised countries, demographic trends in incidence, particularly including socio-economic indicators and substances involved, are less well known.

Aim: To determine demographic patterns and substances related to acute poisoning fatalities and hospital admissions in New Zealand among people at the age of 25 years or older.

Methods: Records with a poisoning external cause of injury code were identified using the national mortality (1999-2008) and hospital discharge (2000-2009) databases, and population-based incidence and trends were analysed.

Results: The 1841 fatalities and 29 881 primary hospital admissions over the 10-year period accounted for mean annual rates of 7.1 and 115.4/100 000, respectively. The majority of deaths from acute poisoning were among males with the converse for hospitalisations for self-poisoning. While hospitalisation for intentional poisoning decreased with advancing age, admissions for unintentional poisoning increased, especially in Pacific people at the age of 65 years or older. Overall, fatality and hospitalisation rates increased with increasing deprivation. Two thirds of deaths and hospitalisations were due to intentional self-poisoning. Carbon monoxide was involved in most fatal intentional self-poisoning events, while pharmaceuticals were the main agent involved in fatal unintentional poisonings and poisoning admissions, irrespective of intent.

Conclusions: The majority of hospitalisations and deaths due to poisoning in New Zealand adults are intentional self-harm episodes. A comprehensive approach to monitoring poisoning, the underlying risks and the implementation of interventions is required to minimise risks.