Trends in emergency department utilization, 1988-1997

Objectives: To study changes in ED utilization over a ten-year period; and to try to identify factors that affect utilization. Methods: This study was conducted in a university-affiliate rural tertiary referral center in a stage 1 managed care market, providing primary emergency services to a county of 120,000 and tertiary services to a 29-county area with 1.2 million people. The year of visit, time of visit, level of care required, length of stay (LOS), and admission status were entered into a computer database for each ED visit. Results: Over the period from 1988 to 1997, the population grew by 18.7%. Over the same time period, the number of ED visits grew 27%. By regression analysis, the number of ED visits was directly related to the size of the service population (correlation coefficient 0.97). During the study period, patient acuity increased, with urgent visits increasing from 45% to 52% while nonurgent visits declined from 55% to 48%. Percentage of patients admitted increased from 14% in 1989 to 20% in 1997. Percentage of patients with LOS exceeding six hours also increased, from 8% in 1989 to 16% in 1997. Conclusions: For the study hospital there was a direct relationship between the ED utilization and population size as well as a historical trend toward increased patient acuity. These trends quantified at one hospital may reflect trends occurring throughout the United States that would affect ED staffing, space, and resource needs.