The common-sense assumption that longer waits in crowded emergency departments are bad for patients' health is bolstered by a new study.
The study, Impact of Emergency Department Crowding on Outcomes of Admitted Patients, published online this week in the Annals of Emergency Medicine, found that admission to the hospital from the ED on days with prolonged ambulance diversion or high ED crowding was associated with 5% increased odds of dying in the hospital compared to admissions on days with low ambulance diversion.
The study also linked crowding to longer hospital lengths of stay and increased costs per admission.
Lead author, Benjamin Sun, MD, an emergency physician with the Oregon Health & Science University in Portland, says the findings confirm what he had expected.
"It is something that seems to resonate with common sense, but there isn't a whole lot of evidence to support it, which is why we think this is a significant paper," Sun says.
The difference is the size and sweep of Sun's study.
"There have been studies that have looked at the relationship between crowding and outcomes. They've been limited in that they look at a roughly small number of patients or hospitals," Sun says.
"The way this differs from prior work is No. 1, we looked at a large number of patients in a large geographic area in California. In contrast, other papers have focused on the patients who were trauma or heart attacks. We looked at everybody who got admitted to the hospital."
The team analyzed 995,379 ED visits resulting in admission to 187 hospitals in California during 2007. Daily ambulance diversion was the measure of emergency department crowding.