Trends in hospital emergency department utilization: United States, 1992-99

This report describes trends in hospital emergency department (ED) visits in the United States. Statistics are presented for overall utilization, case mix of patients, services provided, and outcome measures.

The data presented in this report were collected from the National Hospital Ambulatory Medical Care Survey (NHAMCS) from 1992 through 1999. To make the data points more reliable for trend analysis, the data were combined to provide 2-year annual averages for 1993-94, 1995-96, and 1997-98. The survey in 1992 was especially large so it was used alone. The 1999 data are the most recent year available and are presented separately.

The volume of ED visits in the United States increased by 14% from 1992 through 1999, from 89.8 million to 102.8 million annually. This increase is mainly due to an increase in visits for illness-related as opposed to injury-related conditions. Although the population rate for ED visits did not significantly increase over this time period (rates between 35.7 and 37.9 visits per 100 persons), the rate for illness-related visits rose from 21.0 to 24.0 visits per 100 persons (p < 0.01). The most dramatic increases were observed in the overall visit rate for black persons 65 years of age and over, which rose by 59% from 45.4 visits per 100 persons in 1992 to 72.2 in 1999. For black seniors, both illness and injury-related visit rates increased at a much higher rate compared with trends for white seniors.

Increased volume of ED encounters for persons 45 years of age and over was associated with a greater proportion of illness conditions presenting to the ED and the use of more services, medications, and mid-level providers.