A small study of internal medicine doctors at a New York City hospital found that most doctors go at least a week without laundering their white coats, raising concerns about the spread of infection.

Infographic: 4 keys to engage physicians in care variation reduction

Just how dirty are doctors' white coats?

Edgardo Olvera-Lopez, a third-year resident at Lincoln Hospital in New York who was trained in the United Kingdom, was "shocked" by how dirty his New York colleagues' white coats were. The doctors' coats, which they wore at their patients' bedsides, were often stained, including some stains that looked like blood, according to Olvera-Lopez.

"Rather than white coats, they looked more like brown coats," he said. "I don't know how many weeks or months they went without laundering, but it was definitely something I found disgusting and unprofessional."

To find out how dirty his colleagues' coats really were, Olvera-Lopez last July surveyed attending physicians and other residents in the internal medicine department about how often they wash their white coats. His study was published last November in the American Journal of Infection Control.

Of the 62 respondents, 36% said they wore their coats for seven to 14 days before washing them and 21% said they wore their coats for more than 14 days before the next wash. About 28% said they went three to seven days between washes, while the remaining 15% of respondents said they washed their coats every three days or fewer.

In addition, the study found that more than half of the respondents only owned one white coat, while 29% owned two.

Olvera-Lopez's study also asked his colleagues how they laundered their coats and whether they adhered to the Society for Healthcare Epidemiology of America's (SHEA) guidance on laundering.

SHEA's recommendations state "any apparel worn at the bedside that comes into contact with the patient or patient environment should be laundered after daily use" and "should be laundered no less frequently than once a week and when visibly soiled." When the coats are washed at home, SHEA recommends they be put through a hot water cycle with bleach and then put in the dryer.

The study found 79% of the respondents said they'd never even heard of SHEA's recommendations and a lot of the doctors who knew about the recommendations admitted they didn't follow them. Another 27% of respondents thought the recommendations were unreasonable and difficult to follow.

Are dirty lab coats a public health threat?

The issue with doctors' laundering habits is that the dirty lab coats are "colonized with bacteria during the course of the day" and then worn at patients' bedsides, according to Gonzalo Bearman, main author of the 2014 SHEA guidance and chair of infectious diseases at Virginia Commonwealth University.

However, Bearman said, "We also acknowledged that the impact of doing that on health care-associated infection outcomes remains unknown."

Bearman added that when developing the guidelines, SHEA "aimed for something that was practical."

Olvera-Lopez said a lack of attention to the cleanliness of white coats "happens throughout the nation, and even in other countries. And not just doctors, but respiratory therapists, social workers, anyone who wears a long-sleeved white coat." And while research on the issue is lacking, the fact that the issue is so widespread shows "there's a real need for education about this within the hospital," he said.

Olvera-Lopez noted, "It was shocking to see the reaction from colleagues when I presented these results."

Robert McLean, president of the American College of Physicians, agreed that we should direct more research and attention toward the issue. He added, "There's pretty good data in the literature about ties carrying bacteria," he said.

"I think we get nervous that, especially in hospitals, you may have more immunocompromised people and you don't want anybody spreading things," McClean said. "We wash our hands a lot for that reason, obviously. So why would we wash our hands and not wash our white coats? (Clark, MedPage Today, 1/10).