The Pattern of Emergency Department Use Among People with Mental Health Diagnoses: Results from the 2015 National Hospital Ambulatory Medical Care Survey

Background/Purpose: People with mental health diagnoses tend to visit the Emergency Department (ED) for both injury-related and non-injury related reasons more frequently than those in the general population. However, the experiences of visiting the ED among people with mental health diagnoses are generally negative, often characterized as “feeling disrespected” or “discharged to abyss.” Understanding the pattern of ED use among people with mental health diagnoses can inform the effort of improving the quality of ED services. The length of ED stay is associated with provider stress, risk for adverse events, and patient satisfaction; therefore, has been used to measure the quality of ED services in the health literature. The purpose of this study is to describe ED use among people with mental health diagnoses and to explore factors associated with the length of stay in the ED.

Methods: Data for this study were obtained from the 2015 National Hospital Ambulatory Medical Care Survey that used a four-stage probability sampling design. Mental health diagnoses were identified using a provider’s diagnosis (ICD-9-CM diagnoses 295.X-298.X, 300.X, 303.X-305.X, 311.X). Descriptive statistics were used to describe the national pattern of ED use among people with mental health diagnoses. The Generalized Linear Model (GLM) with a log link was used to explore factors associated with the length of ED stay while accounting for skewed distribution. Sampling weights and complex survey designs were taken into account using the svy package in Stata 15.1.  

Results: Approximately 7% of ED visits were made by people with mental health diagnoses, among which 56% were made by people with substance use disorders, 21% anxiety disorders, 19% mood disorders, and 4% psychotic disorders. The analysis of primary reasons for visits indicated that only about 20% were primarily psychiatric visits. The average age of psychiatric patients was 39.37 (95% CI 37.99 - 40.75). The expected sources of payment included: Medicaid (35%), private insurance (27%), Medicare (14%), and uninsured (13%). The average length of ED visits was 298 minutes. GLM results indicated that people with psychotic disorders were more likely to have a longer length of ED stay (B=.62, p<.01), controlling for age, gender, race/ethnicity, pain-level, triage-level, and payment type. However, the length of ED stay among people with substance use disorders, mood disorders, and anxiety disorders was not significantly different compared with people in the general population.   

Conclusion/Implications: Most ED visits were made by people with substance use disorders consistent with previous studies. Only about 20% of visits were primarily for mental health reasons with other reasons including chest or abdominal pain, shortness of breath, fever, headache, general weakness, and fainting. Notably, patients with psychotic disorders stayed longer than patients with other mental health diagnoses. In the past decade, researchers and clinicians strive to develop interventions to streamline ED use (e.g., staff education or care coordination), particularly for those with substance use disorders and suicide attempt. Findings suggest that this effort may have achieved some success. However, more effort is needed to improve the experience of using ED for people with psychotic disorders.