The effects of ambulance diversion: a comprehensive review.
OBJECTIVE
To review the current literature on the effects of ambulance diversion (AD).


METHODS
The authors performed a systematic review of AD and its effects. PubMed, EMBASE, the Cochrane database, societal meeting abstracts, and references from relevant articles were searched. All articles were screened for relevance to AD.


RESULTS
The authors examined 600 citations and reviewed the 107 articles relevant to AD. AD is a common occurrence that is increasing in frequency. AD is associated with periods of emergency department (ED) crowding (Mondays, mid-afternoon to early evening, influenza season, and when hospitals are at capacity). Interventions that redesign the AD process or that provide additional hospital or ED resources reduce diversion frequency. AD is associated with increased patient transport times and time to thrombolytics but not with mortality. AD is associated with loss of estimated hospital revenues. Short of anecdotal or case reports, no studies measured the effect of AD on ED crowding, morbidity, patient and provider satisfaction, or EMS resource utilization.


CONCLUSIONS
Despite its common use, there is a relative paucity of studies on the effects of AD. Further research into these effects should be performed so that we may understand the role of AD in the health system.
Pham
Julius Cuong
JC
Department of Emergency Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, USA. jpham3@jhmi.edu
Patel
Ronak
R
Millin
Michael G
MG
Kirsch
Thomas Dean
TD
Chanmugam
Arjun
A
D000552:Ambulances / Q000706:statistics & numerical data*; D003441:Crowding; D004636:Emergency Service, Hospital / Q000706:statistics & numerical data*; D006801:Humans; D014187:Transportation of Patients / Q000706:statistics & numerical data*