Non-causative discharge diagnosis from the emergency department and risk of suicide.

Approximately 20% of Emergency Department (ED) users discharged home receive a non-causative discharge diagnosis in the category of "Symptoms, signs, abnormal findings, and ill-defined causes," according to the International Classification of Diseases. The objective of this study was to evaluate the association of these non-causative discharge diagnoses with mortality in general and with violent death and suicide in particular. This is a prospective study; the primary source of data was computer records from the ED at Landspitali University Hospital, Hringbraut, Reykjavik, Iceland over the period 1995-2001. The main discharge diagnoses were recorded according to the International Classification of Diseases. Individuals with a non-causative discharge diagnosis were followed-up for cause-specific mortality through national registries by record linkage and were compared to national mortality rates and the rates of those with causative physical diagnoses. The standardized mortality ratios, hazard ratios, and 95% confidence intervals (CI) were calculated. The data on individuals with a non-causative discharge diagnosis from the ED revealed that the standardized mortality ratio for all causes was 1.57 (95% CI 1.39-1.77) among men and 1.83 (95% CI 1.61-2.08) among women. The hazard ratio for violent death was 1.64 (95% CI 1.07-2.52) and for suicide 2.08 (95% CI 1.02-4.24), adjusted for age and gender, among individuals with a non-causative discharge diagnosis compared to those having causative physical discharge diagnoses. Through analysis of the discharge diagnoses "Symptoms, signs, abnormal findings and ill-defined causes," this study has identified an association between the group of patients discharged from the ED with a non-causative diagnosis who are at high risk of suicide and who may, through further studies, become subjects for suicide prevention strategies.