The study does not prove crowded ERs cause stress disorders, but the researchers suggest their findings show hospital environments may leave a mark on patients' mental health.
The new study builds on previous research by Edmondson that found about one in eight heart attack patients develop post-traumatic stress disorder (PTSD) symptoms, which were tied to the risk of having a second heart attack and dying within three years.
PTSD symptoms include being jumpy or on edge, having nightmares or flashbacks and actively trying to avoid thinking about symptoms.
Other studies have linked heart attacks and PTSD (see Reuters Health story of December 13, 2012 here: http://reut.rs/Xv6fLd), but the researchers write in JAMA Internal Medicine that studies haven't looked at whether a hospital's environment may by tied to the disorder's onset.
In 2009, a survey found over 90 percent of U.S. ER directors said overcrowding is a problem at their hospitals several times per week. They said it led to increased wait times, and it was tied to dissatisfied patients and a higher risk of poor outcomes.
"If you go to an urban emergency department on a busy evening, you may have patients piled up in the hallway, patients with substance abuse problems and patients who are mentally ill," said Dr. Benjamin Sun, who studies hospital overcrowding but was not involved with the new study.
"If you are a patient who is very sick and you are getting care under those conditions, you can see why you'd be traumatized," said Sun, from Oregon Health and Science University in Portland.
For the new study, Edmondson and his colleagues used data collected from medical records and interviews with 135 heart attack patients at one New York City hospital between 2009 and 2011.
On the least busy days, an average of 199 people passed through the ER, compared to an average of 255 on the busiest days.
Heart attack patients who were there on the least busy days scored a 3 on a test that measures PTSD symptoms on a scale from 0 to 88, with higher scores being more severe forms of the disorder. Patients there on the busiest days scored an 8.
Edmondson told Reuters Health that neither group scored high enough to be diagnosed with PTSD, but it's enough of a difference for patients to notice.
"This is not surprising to me," said Sun, who added that there are several possible explanations for the link.
For example, Sun told Reuters Health that patients may pick up on how stressed doctors and nurses are.
Edmondson added that patients may also see or experience a breakdown in communication between nurses and doctors, which can happen in crowded ERs.
There are several ways hospitals can help prevent overcrowding, according to Sun. One possible way is to stop overcrowding throughout the hospital.
Edmondson told Reuters Health the next step is to look at this problem in a larger group of patients at more than one hospital. He added that there may also be a link between crowded ERs and other types of patients.
"I don't think there is anything special in heart attack patient that make emergency departments more likely to cause PTSD," he said.
SOURCE: http://bit.ly/WhLRfj JAMA Internal Medicine, online February 11, 2013.