Data Source Description: Syndromic surveillance provides public health officials with a timely system for detecting, understanding, and monitoring health threats. By tracking symptoms and conditions reported by patients in emergency departments (EDs), public health officials can monitor trends in critical areas. When people seek treatment in the ED, the facility sends de-identified data—including chief complaint, diagnosis codes, patient characteristics, and location—to state and local health departments to share with CDC.

Indicator definitions: Definitions include both (1) visits with acute mental health crises or evaluations where the sole or primary reason for the visit is related to mental health, and (2) visits where a mental health condition may not be the sole reason for the visit but was noted to be present in the discharge diagnosis or chief complaint.

ED data are displayed as rates.

• The rate explains the number of ED visits related to a specific mental health condition out of every 100,000 ED visits. The monthly rate of ED visits related to a condition is calculated as the number of ED visits related to a condition as a fraction of the total number of ED visits in a given month multiplied by 100,000. ED visits with and without mental health conditions where patients were under 12 years old and where age, sex, and race and ethnicity were unknown were included in the denominators when calculating rates for the overall population.

• Rates are also calculated within demographic groups such as age, sex, and race and ethnicity. This is done by comparing the number of ED visits related to a condition within a demographic group as a fraction of the total number of ED visits for that demographic group in a given month multiplied by 100,000.

Data quality and methodology: More than 6,900 health care facilities covering 50 states, the District of Columbia, and Guam contribute data to NSSP daily. More than 80% of U.S. emergency departments send data to NSSP. Data are collected continuously, and for the purposes of this data channel, updated monthly. Monthly counts that are less than 10 either for the complete population or for specific demographic groups are not shown to protect confidentiality and privacy. Note, rate information may change as data are dynamically adjusted as electronic health record information is updated. However, these changes will not typically affect overall trends.

For additional information, please see: Mental Health Data Sources.

Updated monthly.

Tags: emergency department data, nssp, mental health

Last updated: 2025-12-23 18:06:24+00:00