Environmental cleaning, hand hygiene, and other infection prevention practices depend heavily on human action. But what happens between those interventions, when a freshly cleaned high-touch surface is touched and potentially recontaminated?
A 10-year, National Institutes of Health-funded study involving the Veterans Health Administration examined whether continuously active biocidal surfaces could provide an additional layer of protection. In an interview with Infection Control Today (ICT), Erica Mitchell, director of content strategy at EOS Surfaces; Ken Trinder, CEO and founder; and Kate Mitchell, MBA, the COO, discussed the study, its use of Bayesian statistical modeling, and what the findings could mean for infection preventionists evaluating environmental interventions.
Moving Beyond Before-and-After Comparisons
The study used Bayesian statistical modeling, an approach Erica Mitchell described as estimating the probability that an intervention contributed to an observed change rather than simply determining whether the results could have occurred by chance.
Top 3 Takeaways
- The study went beyond a simple before-and-after comparison. Bayesian modeling was used to estimate the probability that the intervention itself contributed to changes in infection rates while accounting for other variables.
- Passive technologies may help address the time between cleaning events. Environmental cleaning and hand hygiene remain essential, but high-touch surfaces can be recontaminated after these interventions.
- No technology should be treated as a “silver bullet.” The panel emphasized that continuously active surfaces should be considered an adjunct to established IPC practices and encouraged IPs to scrutinize the evidence behind product claims.
Kate Mitchell said that distinction can make the results more useful to decision-makers. “The Bayesian model is, I believe, there’s going to be a paradigm shift here,” she said. According to Mitchell, the analysis found a 90% probability of a 50% reduction in infections attributable to the intervention.
The analysis was built on years of previous research examining EOScu, a copper-infused surface material designed for use on high-touch hospital surfaces, including overbed tables. Earlier studies had raised questions about whether the observed HAI reductions could be attributed to the surfaces or to other concurrent changes.
Erica Mitchell said the newer analysis allowed researchers to “quiet the noise” created by potential confounding factors and focus more closely on the intervention. “They were able to fine tune what we know based on 100-plus years of data about disease transmission,” she said.
Why 10 Years of Data Matter
The duration of the research was particularly important because shorter studies may not capture changes in staffing, patient populations, infection prevention practices, or other variables over time.
Kate Mitchell said that previous research inevitably left the question of durability open. “Well, it worked for a year, but what about beyond a year?” she recalled. The latest research, she said, provided an opportunity to examine the intervention across a decade.
The scope of the Veterans Affairs data also allowed for an unusually detailed review. Kate Mitchell said every admission included in the research was manually examined and that the VA's ability to follow patients across the continuum of care provided researchers with extensive data points.
Trinder emphasized that the statistical analysis was conducted by the research team, including a full-time biostatistician. “If you're going to claim public health relevancy to something,” he said, “you've got to have unassailable data.”
Filling the Gaps Between Cleaning Events
The findings also raise a broader question for infection prevention: What role can passive technologies play between routine cleaning and disinfection events?
Even under ideal conditions, Trinder noted, cleaning and hand hygiene occur at particular moments. “The issue is these are all episodic events,” he said. Continuously active technologies, by contrast, do not require staff to initiate them each time a surface is touched.
He cautioned against viewing any individual intervention as a complete solution. “We don't claim to, you know, be the answer to everything,” Trinder said. “We just think we're an important part of the tools that can be deployed now.”
Kate Mitchell was even more explicit: “We don't claim to be the silver bullet.” She suggested that claims of a single solution to the transmission of infection should themselves prompt scrutiny.
Erica Mitchell pointed to the reality of recontamination as the rationale for considering passive interventions. “Even the cleanest hospital needs something to bridge the gap between those episodic cleaning sessions,” she said.
For infection preventionists evaluating such technologies, however, the panel's final message was not to accept claims uncritically. Kate Mitchell urged IPs and EVS professionals to “just keep asking the questions.”
Trinder agreed. “I'm never going to tell them not to be skeptical, not to ask questions, not to really understand what they're buying,” he said.
