Trends in the use and capacity of California's emergency departments, 1990-1999.

STUDY OBJECTIVE: Concerns over the ability of the nation's emergency departments to meet current demands are growing among the public and health care professionals. Data supporting perceptions of inadequate capacity are sparse and conflicting. We describe changes in the use and capacity of California's EDs between 1990 and 1999, as well as trends in severity of patient illness or injury.

METHODS: Data from California's Office of Statewide Health Planning and Development (OSHPD), which describe all hospital and health service use in the state, were analyzed and later verified using a telephone survey of all 320 open EDs in California. Six variables were analyzed: hospital's ownership type (public or private), total number of annual ED visits, severity of patient illness or injury (percentage of visits categorized as critical, urgent, or nonurgent), number of ED beds, proximity to a closed ED, and teaching status. We tested 2 main hypotheses: (1) Have statewide ED visits, ED beds, visits per ED, and visits per bed increased or decreased between 1990 and 1999? and (2) Has severity of patient illness or injury, as reported to OSHPD, changed over the past decade? State level data were analyzed using ordinary least-squares regression. Hospital level data were analyzed using repeated measures analyses.

RESULTS: The number of EDs in California decreased by 12% (P <.0001). The number of ED treatment stations (ie, physical spaces for the treatment of patients) increased by 687 (16%) statewide (P =.0001), or an average of 79 beds per year. The average annual change in ED visits was not statistically significant (P =.5), whereas visits per ED increased by 27% for all EDs (P <.0001), although with differing trends noted at public and private hospitals. At private hospitals, the average increase was 512 visits/ED each year, whereas at public hospitals, visits decreased by an average of 1,085 visits/ED each year (P <.0001). Overall, critical visits per ED increased by 59% (P <.0001), and nonurgent visits per ED decreased by 8% (P <.0001).

CONCLUSION: The number of EDs in California decreased significantly during the 1990s, whereas the number of ED beds increased. Increases in visits per ED, beds per ED, and in the proportion of patients categorized as critical may help explain the perception that ED capacity is inadequate to meet growing demand.