Poisoning is a public health problem that effects all ages, genders, and ethnicities, but certain populations are at increased risk. Unintentional poisoning disproportionately affects lower- and middle-income countries. The epidemiological pattern of poisoning can differ significantly within countries. In Thailand, national poisoning data is collected by voluntary reporting to a poison control center in the capital, Bangkok. Limited poisonings are reported from Chiang Mai, a province in Northern Thailand, though it has the highest suicide rate in the country.

The aim of this study is to describe poisoning epidemiology, examine differences between intentional and unintentional poisonings and, to develop a multivariate predictive model of intentional poisonings in Northern Thailand.

A total of 550 poisoning admissions were identified at Chiang Mai's University Hospital from 01 January 2005 to 31 December 2005. Demographic data were collected retrospectively by manual chart review. Chi-square and t-tests were used to examine differences in poisoning by intent. A step-wise logistic regression analysis was performed to develop a predictive model of intentional poisonings. Factors significantly associated with intentional poisoning were used in a logistic progression model to identify predictors of intentional poisoning.

Younger age was significantly associated with intentional poisoning. There was no demonstrated difference in gender and poisoning intent. Predictors of intentional poisonings were use of chemical agents, high-risk medications (analgesics and psychiatric), unemployment, and younger age.

Interventions should focus on factors that put young adults and the unemployed at greater risk for intentional poisonings. Further interventions are also needed to limit access to potentially lethal doses of chemical agents and high risk medications.