Epidemiology of Emergency Department Visits for Anxiety in the United States: 2009–2011

Data from the 2009–2011 National Hospital Ambulatory Medical Care Surveys (NHAMCS) were used to enumerate and characterize ED visits in which anxiety was the primary reason for the visit or was the resulting primary discharge diagnosis. NHAMCS used a national probability sample of visits to the emergency and outpatient departments of general and short-stay hospitals located in the 50 states and the District of Columbia that were not affiliated with criminal, mental, or other types of institutions, excluding federal, military, and U.S. Department of Veterans Affairs hospitals (17). NHAMCS is a four-stage survey conducted by the National Center for Health Statistics at the Centers for Disease Control and Prevention (17).

Analyses included all ED visits in which the patient declared anxiety to be the primary reason for the visit or in which the provider assigned a primary discharge diagnosis of anxiety state (ICD-9-CM code 300.0), acute reaction to stress (308), adjustment reaction (309), phobic disorders (300.2), and obsessive-compulsive disorders (300.3). A comprehensive list of all conditions included in this study is presented in a box on page 239. A total of 1,029 visits to EDs with anxiety as the primary diagnosis or reason for the visit were identified within the 2009–2011 NHAMCS sample. All data were anonymous, and this study was exempt from review by the institutional review board of Florida State University.

The nationally weighted estimated annual number of anxiety-related visits to the ED is presented in Table 1. A total of 1,247,000 ED visits for anxiety occurred annually between 2009 and 2011, representing .93% (95% confidence interval [CI]=.8–1.0) of all ED visits. The majority of the anxiety-related visits were by females (62%, CI=55.9–68.8), who represented a larger percentage of anxiety ED visits compared with all-cause ED visits (54.9%, CI=54.5–55.3). Non-Hispanic whites made approximately 68% (CI=61.8–75.2) of the anxiety-related ED visits, and non-Hispanic blacks and Hispanics comprised approximately 16% (CI=11.9–20.1) and 13% (CI=10.1–15.9), respectively, of the anxiety-related ED visits. The proportion of total ED visits that were anxiety related was higher among non-Hispanic whites (1.06%) compared with other racial and ethnic groups and among adults between the ages of 18 and 64 compared with other age groups (1.28%) and individuals with self-pay compared with other insurance (1.20%). The proportion of total ED visits that were anxiety related was higher in nonurban versus urban areas (1.04%) and in the Northeast (1.04%) and West (1.02%) compared with other regions of the United States. The proportion of all-cause ED visits that were anxiety related was higher among visits accompanied by substance abuse (2.85%) and other psychiatric disorders (4.48%) than among visits accompanied by cardiovascular and respiratory conditions (.24%).

Less than 10% of anxiety-related ED visits resulted in a hospitalization, and approximately 67% resulted in either being referred back to a medical care professional or being advised to return to the ED if necessary (Table 2). Seven percent of the patients did not receive directions for follow-up. Only 14% of the anxiety-related visits were categorized as immediate/emergent in terms of the immediacy with which the patient should be seen. One-third of the visits were determined to be semiurgent or nonurgent. More than 81% of the visits were initial visits, with only a small proportion being follow-up visits.

The majority (64%) of anxiety-related visits included diagnostic or screening services, and almost one-fourth (23%) included medical procedures (Table 3). A mental health specialist was seen in only 13% of anxiety-related ED visits. Medications were given or prescribed at ED discharge in 68% (CI=61.0–75.1) of anxiety-related visits. Anxiolytics and benzodiazepines (53.2%) were most often prescribed for anxiety-related ED visits when drug therapy was provided in the ED. A small minority of the study population was prescribed antidepressants (4.5%), antipsychotics (3.1%), or narcotics (5.2%) during the anxiety-related ED visit.

Between 2009 and 2011, ED visits for anxiety (either as reason for visit or as discharge diagnosis) accounted for .93% of all ED visits. This proportion of ED visits is larger than the reported proportion of depression-related ED visits between 1997 and 2000, which was about .60% of visits (3). These results are also consistent with findings that anxiety visits account for a higher proportion of all mental health–related ED visits compared with visits for depression (18).

Although the distribution of payer source was similar for ED visits for anxiety and all-cause ED visits, privately insured and Medicaid recipients accounted for the largest percentage of the anxiety-related ED visits, suggesting that lack of insurance coverage is not the primary reason for ED utilization. Previous findings that rates of ED visits tend to be much higher for Medicaid recipients than for persons with private insurance (19) further support the possibility that persons with anxiety have distinctive health-seeking behavior. Perhaps individuals with undiagnosed or untreated anxiety disorders develop acute symptomatology and ultimately seek primary care within the ED. One consequence of Medicaid patients’ lack of access to primary care is greater reliance on the ED (20). In addition, patients may feel a sense of urgency generated by symptoms such as anxiety, leading to particularly acute needs for immediate access to care (21).

Several findings from this study have important implications for health service interventions. The vast majority of visits were initial visits, constituting a critical opportunity for brief interventions that may improve self-management of anxiety and decrease repeat ED visits. In addition, fewer than one in six anxiety-related visits included care by a mental health specialist. Hospital-based mental health consultation is likely to improve proper diagnosis and management (22). The common practice of providing negative test results and reassurance regarding NCCP, for example, has not been shown to affect use of ED visits among patients with anxiety disorders (23). Anxiety-focused counseling approaches may be more effective.

It is important to note that for the majority of visits, patients were prescribed anxiolytic medications. These medications have potential for abuse and overdose, have been found to have a modest effect on long-term management of anxiety disorders, and are not likely to prevent reuse of ED services. In fact, a number of studies have found that behavioral interventions, such as cognitive-behavioral therapy, are more effective than medications in the amelioration of anxiety symptoms and prevention of recurrence (24,25). Studies have shown that even very brief behavioral interventions are effective (23), as are SSRIs (26). Even the integration of an anxiety screening tool may not be feasible or effective as a diagnostic tool without the assistance of a mental health provider (27). On the basis of these findings, it seems likely that integration of mental health specialists within both ED and primary care may drastically improve clinical outcomes and reduce repeated ED visits.

According to the National Institute of Mental Health, antidepressants, antianxiety drugs, and beta blockers are the medications primarily used for treatment of anxiety disorders. Our findings demonstrate that anxiolytics and benzodiazepines were the drugs prescribed most often when drug therapy was employed in the ED. This form of drug therapy is potentially dangerous because of risk of overdose and addiction. Although this drug category may offer immediate anxiety symptom relief, physicians should exercise a high level of caution given the potential for harm. Most surprising was the finding that physicians prescribed narcotics during a larger proportion of visits than they prescribed antidepressants. Further research is required to elucidate this potentially dangerous pattern of drug prescribing for persons with anxiety.

For individuals who are not in imminent danger, referrals to mental health specialists would be appropriate, whereas for those who are in imminent danger, admission to the hospital or transfer to a psychiatric facility would be the best course of action (3). Consistent with previous triage patterns, half of the anxiety-related visits were classified as urgent (18). Because only a small proportion of study visits were classified as immediate/emergent, the most common disposition for anxiety patients was receiving instruction to consult with the referring physician. The small proportion of immediate/emergent visits suggests that the ED—rather than mental health specialists—was the primary source of care for anxiety-related distress. Notably, 7% of the patients were not advised to make plans for follow-up. Despite the previously reported low level of compliance with referrals for follow-up (28), an appropriate level of care should nevertheless include referral to a mental health counselor or their primary care physician.

Persons from racial-ethnic minority groups may be at higher risk of developing mental disorders because of social and environmental difficulties (29). However, prevalence rates of anxiety among racial-ethnic minority groups are a more controversial topic, given that qualitative studies are more likely than quantitative studies to show an elevated level of psychological distress among racial-ethnic minority groups (30). Although anxiety-related ED visits were most frequent among non-Hispanic whites in this study, persons from racial-ethnic minority groups represented more than one-third of these visits. These findings may reflect disparities in access to outpatient mental health treatment.

Some limitations of this study should be acknowledged. The study methodology and the nature of the data set prevent making inferences regarding causation. The CDC acquires information regarding patient visits from the provider for a truncated period of time, precluding follow-up. Findings regarding medication prescriptions must be interpreted cautiously, given that the presence of other medical conditions may have necessitated these prescriptions. In addition, the study relied on patient-reported anxiety symptoms or physician discharge diagnoses and not on structured diagnostic assessments. It is possible that some of the patients who generated these visits did not meet the diagnostic threshold for an anxiety disorder. However, this study calculated rates of visits and treatment for anxiety by including only visits in which the patient or physician had identified anxiety as the primary diagnosis or reason for the visit. The purpose of this study was to present a detailed summary of ED visits for anxiety-related issues, with the specific intent to provide a foundation for future research on the health-seeking behavior of and quality of health care received by persons with anxiety disorders.

Most important, it is possible that this study did not capture all visits to the ED for anxiety-related reasons, and therefore the rates presented are likely underestimates. To control for potential undercounting, we also included “reason for visit” in an attempt to include as many anxiety-related ED visits as possible. Despite these efforts, it is probable that this study underestimated the number of visits. For example, the attending physician may not have recognized the symptoms as being related to anxiety and may have attributed the symptoms to another condition and treated the patient accordingly. In addition, the patient may not have recognized that the symptoms—for example, chest pains—were related to anxiety and, therefore, may not have reported anxiety as the reason for the visit to the ED. The majority of patients who seek emergency care for acute chest pain are released from the ED with noncardiac diagnoses, given that chest pain is a common symptom of certain psychiatric disorders (31). Recognizing the potentially treatable anxiety disorders that are highly concurrent with somatic symptoms, therefore, is important. Missed anxiety-related visits highlight the need for better screening for anxiety in the ED and better training to care for persons with anxiety.

Despite its limitations, this study represents the first attempt to specifically quantify the burden of anxiety in a representative national sample of U.S. ED visits. The use of the ED for anxiety-related visits suggests that the diagnosis of anxiety either is not caught or is left untreated in primary care and that further work is needed to ensure access to outpatient mental health care, where appropriate care of anxiety is more likely. This study also provides a detailed description of the characteristics of ED visits for anxiety in terms of content of care and visit disposition and provides a comprehensive foundation for future research to address the health care–seeking behavior of persons with mental health issues.