Repetition of acute poisoning in Oslo: 1-Year prospective study

Abstract

Background: The repetition of acute poisoning occurs frequently. The intention may change between episodes and many poisonings are treated outside the hospital setting. Few studies have taken this into account. Aims: To quantify the repetition frequency regardless of the level of health care or the intention behind the poisoning, and to identify possible risk factors for repetition. Method: A prospective multicentre study of all acute poisonings in Oslo treated in hospital, at an out-patient clinic or by the ambulance service. Repetition was estimated using Kaplan-Meier calculations, and predictive factors were identified using Cox regression analysis. Results: The estimated 1-year repetition rate was 30% (95% CI 24-35). Independent predictors of repetition were middle age (30-49 years), poisoning with opiates or sedatives, unemployment or living on social welfare, a previous suicide attempt, and a history of psychiatric treatment. Intention was not a significant predictor. Conclusions: Repetition of acute poisoning is high, irrespective of the level of healthcare and the intention behind the poisoning.