Objective To quantify the relationship between imitative behaviour and poisonings in children.

Setting USA.

Methods This study is based on the evaluation of a large national database of unintentional oral ingestion poisonings involving children aged <5 years treated in US hospital emergency departments during 2004 and 2005. It begins with the premise that, among other factors, oral drug poisonings can result from children observing and imitating adult behaviour, but that non-oral drug and non-drug poisonings (to be referred to as non-drug poisonings) generally do not, because children do not see adults ingesting non-drug products. The study then compares and contrasts the child poisonings between the two poisoning categories. Differences in the poisoning rate between the oral drug and non-drug categories are estimated by the age and sex of the children. A binary logistic regression analysis is also conducted using non-drug poisonings as a control group to compare against oral drug poisonings.

Results There was a significant increase in the relative likelihood of oral drug poisonings beginning at age 20–23 months that is consistent with the expected onset of complicated imitative behaviours in children. Based upon our analysis, imitative behaviour may have contributed to about 17 300 child poisonings treated annually in the emergency department, possibly accounting for about 20% of poisonings involving children aged <5 years and 30% of the poisoning injuries involving children aged 20–59 months.

Conclusions Comprehensive efforts to prevent poisoning need to address the problem of imitative behaviour in children. Caregivers should never ingest medications in the presence of children.