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

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.