Emergency Department Ambulance Diversion Research Articles

Emergency department ambulance diversion: a thing of the past?

Emergency department ambulance diversion: a thing of the past?

8: The Effects of Emergency Department (ED) Ambulance Diversion on Pediatric Mortality in a Large Metropolitan Area

To determine the association between ED ambulance diversion and pediatric mortality.

Effects of Hospital Closures and Hospital Characteristics on Emergency Department Ambulance Diversion, Los Angeles County, 1998 to 2004

We assess the effects of nearby hospital closures and other hospital characteristics on emergency department (ED) ambulance diversion. The study design was a retrospective, multiple interrupted time series with control group. We studied all ambulance-receiving hospitals with EDs in Los Angeles County from 1998 to 2004. The main outcome measure was monthly ambulance diversion hours because of ED saturation. Our sample included 80 hospitals, of which 9 closed during the study period. There were increasing monthly diversion hours over time, from an average of 57 hours (95% confidence interval [CI] 51 to 63 hours) in 1998 to 190 hours (95% CI 180 to 200 hours) in 2004. In multivariate modeling, hospital closure increased ambulance monthly diversion hours by an average of 56 hours (95% CI 28 to 84 hours) for 4 months at the nearest ED. County-operated hospitals had 150 hours (95% CI 90 to 200 hours) and trauma centers had 48 hours (95% CI 9 to 87 hours) more diversion than other hospitals. Diversion hours for a given facility were positively correlated with diversion hours of the nearest ED (0.3; 95% CI 0.28 to 0.32). There was a significant and positive interaction between diversion hours of the nearest ED and time, suggesting that the effects of an adjacent facility's diversion hours increased during the study period. Hospital closure was associated with a significant but transient increase in ambulance diversion for the nearest ED. The temporal trend toward more diversion hours, as well as increasing effects of the nearest facility's diversion hours over time, implies that the capacity to absorb future hospital closures is declining.

Community influenza outbreaks and emergency department ambulance diversion

Study objectiveInfluenza has been linked to emergency department (ED) crowding, yet few studies have examined this association. We describe the relationship between ED crowding and influenza outbreaks. MethodsA retrospective time series analysis was conducted in Toronto from January 1996 to April 1999 (n=170 weeks). We obtained weekly data on laboratory-confirmed influenza and other respiratory virus cases in the community, ED ambulance diversion, and visits to all city EDs (n=20). The main outcome was ambulance diversion, measured as the mean number of hours per week in which EDs were forced to divert all ambulances. ResultsA mean of 10,936 ED visits occurred weekly (average age of patients 39.9 years; 51% female patients). EDs diverted ambulances an average of 3.4 hours per week (range 0.3 to 15 hours). Four influenza seasons occurred, lasting between 18 and 30 weeks each, with weekly influenza case counts ranging from 0 to 236. There were fewer than 10 cases per week in 119 of 170 weeks (70%). In time-series models, influenza was independently associated with ED ambulance diversion (P<.0001). For every 100 cases of influenza in the community in a given week, ED ambulance diversion would be expected to increase by 2.5 h/wk at the average ED (95% confidence interval [CI] 1.2 to 3.9 h/wk). During influenza seasons, 24.3% (95% CI 11.3% to 37.2%) of observed weekly ambulance diversion was attributable to influenza. ConclusionInfluenza seasons are associated with increased ED ambulance diversion. The impact is substantial but brief because there is little or no influenza activity most of each year.