Herd Immunity: Study Shows ICU Gown, Glove Use Can Cut MRSA Rates by 40%

Wearing gloves and gowns in health care settings lower infection rates, a new study shows.

But, wait. Wearing gloves and gowns doesn’t lower infection rates. That’s from the same study.

And hence the confusion in the media over the past week over whether doctors and nurses should even bother covering their hands and bodies or just show up in t-shirts, shorts, and flip flops every day. If you’re going to pass along a potentially fatal, highly infectious disease to your patient, why not do it in comfort?

These were some of the headlines:

Gowns And Gloves For Hospital Workers Could Cut MRSA Rates

Universal Glove, Gown Use Doesn't Cut MRSA, VRE in ICU

Wearing Gowns and Gloves Helps Prevent MRSA

No overall benefit with universal gown, glove use

Now, what did the study, published online on October 4 in the Journal of the American Medical Association, actually say?

First, it’s worth noting that this was a fairly extensive effort on the part of researchers from the University of Maryland School of Medicine and the Yale New Haven Health System Center for Healthcare Solutions. They didn’t just go to their respective intensive care units and look at a few patient files. They enrolled 20 ICUs from 15 states to participate in a ten-month study last year year. They analyzed more than 92,000 bacterial cultures from 26,180 patients.

One group of health care workers wore gloves and gowns any time they were in a patient’s room. Let’s call them the Gowns. The other group wore them only when dealing with patients already infected with antibiotic-resistant bacteria, which is in accord with the Centers for Disease Control and Prevention’s “standard isolation protocol.” Let’s call them the Skins.

The researchers measured infection rates prior to the start of the Gowns vs. Skins competition so they could see whether the change made an improvement, made no difference at all, or made things worse. They looked for the acquisition of MRSA (methicillin-resistant staphylococcus aureus) or VRE (vancomycin-resistant enterococci). And they calculated these acquisitions as a rate per patient day. One patient in the ICU for one day is a patient day. When the same patient stays another day, that’s two patient days, and when a new patient comes to the ICU for a day, that’s a third patient day.

Bear with me a bit while I explain what they found.

For the Gowns, acquisitions of MRSA or VRE fell to  from 21.35 acquisitions per 1000 patient-days (95% CI, 17.57 to 25.94) in the baseline period to 16.91 acquisitions per 1000 patient-days (95% CI, 14.09 to 20.28) in the study period. That seems pretty good. But look at what happened with the Skins. They saw a drop from 19.02 acquisitions in the baseline period to 16.29 acquisitions per 1000 patient-days. The end result? No statistically significant difference. And hence some of the headlines saying that gowns and gloves didn’t matter.

When you break it down by the bacteria, though, you see that gloves and gowns do appear to work against MRSA. For the Gowns, ICUs saw a decrease from 10.03 acquisitions per 1,000 patient days in the baseline period to 6 acquisitions in the study period. That’s a 40% decrease. What about the Skins? They went from 6.98 acquisitions to 5.94 acquisitions per 1,000 patient-days. That’s a 14% decrease. And this time the differences were determined to be statistically significant.

Why does all of this matter?

"Healthcare workers are the most important vector in the spread of antibiotic-resistant bacteria," study co-author Dr. Anthony Harris from the University of Maryland said, according to Michael Smith at MedPage Today.

Smith also wrote:

The universal use of gloves and gowns cut the number of the times healthcare workers entered patient rooms -- 4.28 entries per hour compared with 5.24 in the control units.

The intervention units also saw better hand hygiene when workers left patient rooms, he reported, and the intervention had no significant effect on the rate of adverse events.

The findings show some promise for preventing transmission of multidrug-resistant pathogens, commented Mary Hayden, MD, of Rush University Medical Center in Chicago.

But, she said, there are some possible drawbacks. "The cost would be a downside," she told MedPage Today, "as well as the trash that you would generate, because (the gowns and gloves) are all disposable."

Have your own thoughts on the value of gowns and gloves? Write me at askantidote [at] gmail.com or on Twitter @wheisel.