The effect of emergency department crowding on analgesia in patients with back pain in two hospitals

Document Type

Journal Article

Publication Date



Academic Emergency Medicine


Volume 17, Issue 3

Inclusive Pages



Analgesia--statistics & numerical data; Back Pain--drug therapy; Crowding; Emergency Service, Hospital--statistics & numerical data; Emergent Care; Quality Improvement



The authors assessed the association between measures of emergency department (ED) crowding and treatment with analgesia and delays to analgesia in ED patients with back pain.


This was a retrospective cohort study of nonpregnant patients who presented to two EDs (an academic ED and a community ED in the same health system) from July 1, 2003, to February 28, 2007, with a chief complaint of "back pain." Each patient had four validated crowding measures assigned at triage. Main outcomes were the use of analgesia and delays in time to receiving analgesia. Delays were defined as greater than 1 hour to receive any analgesia from the triage time and from the room placement time. The Cochrane-Armitage test for trend, the Cuzick test for trend, and relative risk (RR) regression were used to test the effects of crowding on outcomes.


A total of 5,616 patients with back pain presented to the two EDs over the study period (mean+/-SD age=44+/-17 years, 57% female, 62% black or African American). Of those, 4,425 (79%) received any analgesia while in the ED. A total of 3,589 (81%) experienced a delay greater than 1 hour from triage to analgesia, and 2,985 (67%) experienced a delay more than 1 hour from room placement to analgesia. When hospitals were analyzed separately, a higher proportion of patients experienced delays at the academic site compared with the community site for triage to analgesia (87% vs. 74%) and room to analgesia (71% vs. 63%; both p<0.001). All ED crowding measures were associated with a higher likelihood for delays in both outcomes. At the academic site, patients were more likely to receive analgesia at the highest waiting room numbers. There were no other differences in ED crowding and likelihood of receiving medications in the ED at the two sites. These associations persisted in the adjusted analysis after controlling for potential confounders of analgesia administration.


As ED crowding increases, there is a higher likelihood of delays in administration of pain medication in patients with back pain. Analgesia administration was not related to three measures of ED crowding; however, patients were actually more likely to receive analgesics when the waiting room was at peak levels in the academic ED.

Peer Reviewed