Emergency Department Visit Rates by Selected Characteristics: United States, 2019 Data from the National Hospital Ambulatory Medical Survey,

In 2019, an estimated 151 million emergency department (ED) visits occurred in the United States and about 22% of adults aged 18 and over had visited the ED in the past 12 months (1,2). This report presents ED visit rates by selected characteristics, including metropolitan statistical area (MSA) status, age, sex, race and ethnicity, and health insurance status. Data for this report are from the National Hospital Ambulatory Medical Care Survey (NHAMCS), an annual nationally representative survey of nonfederal, general, and short-stay hospitals (3,4).

• The ED visit rate was highest for infants under age 1 year (123 visits per 100 people) followed by adults aged 75 years and over (66 per 100).
• The ED visit rate for non-Hispanic Black people (87 visits per 100 people) was higher than the rate for people from all other racial and ethnic groups.
• The ED visit rate for patients with private insurance was lowest, while the rate for patients with Medicaid or Children's Health Insurance Program/State Children's Health Insurance Program was highest compared with all other primary expected sources of payment.
In 2019, an estimated 151 million emergency department (ED) visits occurred in the United States and about 22% of adults aged 18 and over had visited the ED in the past 12 months (1,2). This report presents ED visit rates by selected characteristics, including metropolitan statistical area (MSA) status, age, sex, race and ethnicity, and health insurance status. Data for this report are from the National Hospital Ambulatory Medical Care Survey (NHAMCS), an annual nationally representative survey of nonfederal, general, and short-stay hospitals (3,4).  What were the ED visit rates for each age group, and did these rates vary?

What were the ED visit rates overall and by
• In 2019, the ED visit rate for infants under age 1 year was 123 visits per 100 infants, which was highest compared with all other age groups ( Figure 2).
• The ED visit rate for adults aged 75 and over was 66 visits per 100 people, which was higher than the rates for all other age groups, except infants under 1 year.
• ED visit rates were similar for all other age groups, ranging from 41 to 47 visits per 100 people. What were the ED visit rates by sex and by race and ethnicity, and did these rates vary?
• The observed difference in the ED visit rate for females (50 visits per 100 females) and males (43 visits per 100 males) was not significantly different ( Figure 3).
• In 2019, the ED visit rate for non-Hispanic Black people was 87 visits per 100 people, which was higher than the rates for people from all other racial and ethnic groups shown.
• The ED visit rate for non-Hispanic other people (includes American Indian or Alaska Native, Asian, and Native Hawaiian or Other Pacific Islander people, and people with two or more races) was 19 visits per 100 people, which was lower than the rate for non-Hispanic White, non-Hispanic Black, and Hispanic or Latino people.
• The ED visit rates for Hispanic or Latino people (44 per 100 people) and non-Hispanic White people (43 per 100) were similar.   (Figure 4).
• The ED visit rate was lowest for patients with private insurance (19 visits per 100 people).
• The ED visit rate for patients with Medicare (52 per 100 people) was higher compared with rates among uninsured patients (39 per 100) and patients with another primary expected source of payment (38 per 100).

Summary
This report examines 2019 ED visit rates by selected characteristics and presents trends from 2009 through 2019. The overall ED visit rate and visit rates by MSA status did not change significantly between 2009 and 2019. The ED visit rate for infants under age 1 year was higher than the rates for all other age groups, and the rate for adults aged 75 and over was higher than the rates for all other age groups, except infants. The ED visit rate for non-Hispanic Black people was higher than the rates for people from all other racial and ethnic groups. The ED visit rate for patients with Medicaid or CHIP/SCHIP was higher than the rates for all other sources of payment, and the rate for private insurance was lower than the rates for all other sources of payment. This report shows that there is wide variation in ED visit rates by selected characteristics. Primary expected source of payment: During data collection, all sources of payment were collected. For patients with more than one source of payment, the hierarchy below was used (with Medicare counted first and self-pay and no charge counted last) to collapse payments into one mutually exclusive variable (primary expected source of payment).

Definitions
• Medicare: Partial or full payment by Medicare plan includes payments made directly to the hospital as well as payments reimbursed to the patient. Charges covered under a Medicaresponsored prepaid plan are included.
• Medicaid or CHIP/SCHIP: Partial or full payment by Medicaid or CHIP/SCHIP plan includes payments made directly to the hospital or reimbursed to the patient. Charges covered under a Medicaid-sponsored prepaid plan (HMO) or "managed Medicaid" are included.
• Private: Partial or full payment by a private insurer (such as BlueCross BlueShield), either directly to the hospital or reimbursed to the patient. Charges covered under a private insurance-sponsored prepaid plan are included.
• Uninsured: Includes self-pay and no charge or charity. Self-pay are charges paid by the patient or patient's family that will not be reimbursed by a third party. Self-pay includes visits for which the patient is expected to be responsible for most of the bill, even if the patient never actually pays it. This does not include copayments or deductibles. No charge or charity are visits for which no fee is charged (such as charity, special research, or teaching). Race and ethnicity: Race and Hispanic ethnicity were collected separately, imputed, and converted into a single combined variable that includes non-Hispanic White, non-Hispanic Black, Hispanic, and non-Hispanic other people. Non-Hispanic other includes Asian, Native Hawaiian or Other Pacific Islander, and American Indian or Alaska Native people, and people with two or more races. For 2019, 19.7% of race data and 17.4% of ethnicity data were missing for ED visits; race and ethnicity were imputed for these missing records. Race and ethnicity data were imputed on the data file using a model-based, single, sequential regression imputation method (3,4).
Missing race values were imputed to be White, Black, or other. Hispanic ethnicity was imputed to be Hispanic or non-Hispanic.

Data source and methods
Data for this report are from NHAMCS, an annual nationally representative survey of nonfederal, general, and short-stay hospitals (3,4). NHAMCS provides data on the use and provision of ambulatory care services in hospital emergency departments. In 2019, the weighted NHAMCS response rate was 82.9%. Data analyses were performed using the statistical packages SAS version 9.4 (SAS Institute, Cary, N.C.), SAS-callable SUDAAN version 11.0 (RTI International, Research Triangle Park, N.C.), and Joinpoint Regression Program version 4.7.0.0. Two-tailed t tests with a significance level of p < 0.05 were used to determine statistically significant differences between ED visit rates.

About the authors
Christopher Cairns, Jill J. Ashman, and Kai Kang are with the National Center for Health Statistics, Division of Health Care Statistics.