Ambulance diversion as a proxy for emergency department crowding: the effect on pediatric mortality in a metropolitan area.

OBJECTIVES: The objective was to determine the prevalence of emergency department (ED) ambulance diversion among Houston pediatric hospitals and its association with mortality of pediatric patients.

METHODS: Hospital diversion and patient data between August 2002 and December 2004 were used to examine the impact of diversion on mortality of children under age 18 years. Patients were assumed to be exposed to ED crowding if diversion and admission or ED arrival times overlapped. Univariate and logistic regression were performed to determine if diversion was associated with mortality while controlling for age, illness severity, injury, and transfer status.

RESULTS: Mean hospital diversion hours as a percentage of operating hours were 10.58 (standard deviation [SD] +/- 9). Overall, of 63,780 admissions, there were 4,095 (6.4%) children admitted during diversion. Fewer severely ill patients were admitted during diversion than nondiversion times (odds ratio [OR] = 0.72; 95% confidence interval [CI] = 0.66 to 0.78). The presence of diversion was protective for mortality (OR = 0.51; 95% CI = 0.34 to 0.77) in bivariate analysis. Mortality was associated with presence of major or extreme illness (OR = 60.7; 95% CI = 45.2 to 81.5), injury (OR=1.7; 95% CI = 1.4 to 2.1), and transfer status (OR = 6.3; 95% CI = 5.4 to 7.3). Using conditional logistic regression, major or extreme illness (OR = 50.7; 95% CI = 37.7 to 68.3), injury (OR 3.7; 95% CI = 2.9 to 4.7), and transfer (OR = 2.7; 95% CI = 2.2, 3.2) were associated with mortality, but diversion did not show any association with mortality. After combining ED and inpatient deaths, no association between diversion and mortality was observed.

CONCLUSIONS: Hospital diversion due to ED crowding is common in pediatrics. The authors found no evidence of an association between diversion and ED and inpatient pediatric mortality.