<b>Background:</b> Self-poisoned patients are often admitted to a medical unit. However, often no treatment is given. We have developed a model to predict those patients who will not be treated and how long patients should be observed before this prediction can be safely made.
<b>Methods:</b> In this retrospective study a model to predict treatment was developed based on cases of self-poisoning in 1996 and validated on cases between 1997 and 1999. In a teaching hospital in the Netherlands 299 adults performing 353 episodes of self-poisoning were studied. The main outcome measures were predicted versus initiated medical treatment, time to prediction and time to initiation of treatment.
<b>Results:</b> The model predicted that in 51% (156/307) of all autointoxications no treatment would be given. In 2% (6/307) of all cases, treatment was incorrectly not predicted. All but one of these were preventive treatments based on the ingested compound. 4.5 hours after admission no additional patients fulfilled the criteria for prediction of treatment and all treatments were started within 4.5 hours.
<b>Conclusions:</b> In 51% of patients that present with an autointoxication the model accurately predicts that no treatment will be initiated. This decision can be made in the first 4.5 hours after presentation. This model can be used for a first screening of patients. It can also be used as a basis for a further prospective study to establish rational guidelines in the management of these patients.