Published online July 1, 2005
PEDIATRICS
Vol. 116
No. 1
July 2005, pp.
295
(doi:10.1542/peds.2005-0913)
Emergency Department Wait Times
Catherine James, MD
Florence Bourgeois, MD
Michael Shannon, MD
Division of Emergency Medicine,
Department of Pediatrics,
Children's Hospital Boston,
Harvard Medical School,
Boston, MA 02115
In Reply.
We appreciate the comments from Brousseau and Gorelick regarding our article on the association between race/ethnicity and emergency department (ED) wait times and would like to respond to the questions that they raised.
As they state, ED wait time varies according to time of day, and it varied in a similar manner for each of the groups studied in the National Hospital Ambulatory Medical Care Survey data. Overall, 12.7% of children arrived between 12 AM and 7 AM, 36.8% between 8 AM and 3 PM, and 50.8% between 4 PM and 11 PM. The results are similar when examined by race/ethnicity. For non-Hispanic white (NHW) patients, 12.2% arrived between 12 AM and 7 AM, 36.1% between 8 AM and 3 PM, and 51.7% between 4 PM and 11 PM. For non-Hispanic black (NHB) patients, 13.7% arrived between 12 AM and 7 AM, 38.8% between 8 AM and 3 PM, and 47.6% between 4 PM and 11 PM. For Hispanic white (HW) patients, 13.2% arrived between 12 AM and 7 AM, 36.5% between 8 AM and 3 PM, and 50.4% between 4 PM and 11 PM. There was no difference in time of presentation for different race/ethnicity groups. It therefore is unlikely that differences in time of presentation explain the differences in wait times that we found between race/ethnicity groups.
A new variable was added to the regression model to test for effect modification of race/ethnicity on triage assignment. The P value for this term was .004, indicating that there indeed is effect modification. This means that, for NHB and HW patients, being triaged in a more nonurgent triage group has a greater effect on waiting time than for NHW patients. Mean wait time was 21.7 minutes for NHW patients in the group triaged as needing care in <15 minutes, 22.0 minutes for NHB patients, and 27.8 minutes for HW patients. In the category of those needing care in <1 hour, mean wait time was 34.7 minutes for NHW patients, 38.1 minutes for NHB patients, and 47.6 minutes for HW patients. In the category of those needing care within 1 to 2 hours, mean wait time was 49.4 minutes for NHW patients, 57.9 minutes for NHB patients, and 69.5 minutes for HW patients. In the category of those needing care in >2 to 24 hours, mean wait time was 51.0 minutes for NHW patients, 74.7 minutes for NHB patients, and 71.1 minutes for HW patients. Therefore, as the authors of the letter suggest, the results of the regression analysis seem to be driven by the race/ethnicity groups in the more nonurgent categories.
We report the percentage change in minutes instead of simply minutes, because for the regression analysis, we had to use log-transformed wait time as our outcome because this variable is nonnormal. The ß values that we obtain with this analysis are relative values, and to make them more interpretable, the following transformation was made: (eß – 1) x 100 = percentage change in wait time.
Wait times are generally longer in pediatric EDs when compared with general EDs. A pediatric ED is defined as one that sees 
75% pediatric patients (patients <19 years of age). In our analysis of National Hospital Ambulatory Medical Care Survey data, the mean wait time in pediatric EDs was 51.9 minutes for NHW patients, 54.3 minutes for NHB patients, and 64.0 minutes for HW patients, with an overall mean of 56.9 minutes. In general EDs, the mean wait time for NHW patients was 36.9 minutes, 48.2 minutes for NHB patients, and 51.4 minutes for HW patients; the overall mean was 41.9 minutes. The trend is the same for the 2 ED types: NHW < NHB < HW. However, in pediatric EDs, wait times are similar for NHW and NHB patients, with a large increase for HW patients, whereas in general EDs, the wait times were more similar for NHB and HW patients and much less for NHW patients.
PEDIATRICS (ISSN 1098-4275). ©2005 by the American Academy of Pediatrics
