Emergency department utilization by patients with bipolar disorder: a national population-based study

Background: There is a scarcity of national United States (US) data on emergency department (ED) utilization of patients with bipolar disorder (BD). This study aims to determine the most common reasons for ED visits of patients with BD, and baseline characteristics of patients who present due to BD. Methods: We obtained data from the Nationwide Emergency Department Sample (NEDS), the largest all-payer ED database in the US. Each ED visit in NEDS 2018, can have only 1 "principal " diagnosis, which is the main reason for hospitalization, and up to 34 "secondary " diagnoses. We extracted data for all ED visits with "any " diagnosis of BD, using the ICD-10 code. We highlighted the 5 most common "principal " diagnoses based on the organ system involved and the 10 most specific "principal " diagnoses for all ED visits by patients with "any " diagnosis of BD. We highlighted baseline characteristics of ED visits with a "principal " diagnosis of BD. Results: A total of 2,200,197 ED visits for patients with BD in 2018. Mental disorders such as BD, suicidal ide-ations, anxiety disorders and injuries and poisoning were common reasons for presentation to the ED. Among these, 291,319 had BD as the principal diagnosis. These patients were more likely to come from lower-income households. Limitations: Possibility of coding errors due to ICD coding, and absence of data on race and medication compliance. Conclusions: BD, suicidal ideation, and anxiety disorders were the most common specific psychiatric reasons for presentation to the ED among patients with BD.