New research released in JAMDA said the way nursing centers gauge the susceptibility of their residents to infections by using measurements from the acute-care setting is not often accurate. The report said the so-called acute-care antibiograms for residents should be used with caution, if at all, in guiding empiric antibiotic therapy in the post-acute and long term care setting.

Empiric antimicrobial therapy is directed against an anticipated and likely cause of infectious disease. And, in layman’s terms, an antibiogram is a report that shows how susceptible strains of germs (pathogens) are to a variety of antibiotics.

In “Antibiograms Cannot Be Used Interchangeably Between Acute-care Medical Centers and Affiliated Nursing Homes,” report authors compared antibiograms for Veterans Affairs nursing homes (VANH) with their affiliated VA medical centers (VAMC).

Researchers found that none of the NH-VAMC pairs demonstrated complete agreement (all bacteria versus all antibiotics) between their antibiograms. “On average, 20 percent of the bacteria-antibiotic comparisons from the antibiograms disagreed clinically, and almost twice as often the VANH had lower susceptibility (higher resistance) than the VAMC,” the report said.

In the case of the study, antibiograms are profile reports of antibiotic susceptibility rates of bacteria from a single facility over a duration of a calendar year. These reports are used to guide antibiotic prescribing and to track emerging bacterial resistance within the facility.

Researchers said that “due to a lack of resources and a low number of clinical cultures, the creation of antibiograms in nursing home settings can often be challenging.” That’s why they often use reports from nearby or affiliated acute-care facilities.  

The authors concluded that while their work showed only a moderate lack of agreement between VANH and VAMC antibiograms, the difference was enough to suggest that acute-care reports are often not accurate approximations of NH resistance patterns.  

JAMDA said the study was conducted by, among others, researchers at the Infectious Diseases Research Program, Providence Veterans Affairs Medical Center, Providence, R.I., and the Center of Innovation for Long Term Care Services and Supports, Providence Veterans Affairs Medical Center, also in Providence.

JAMDA is the official journal of AMDA, The Society for Post-Acute and Long-Term Care Medicine, and is the leading peer-reviewed publication for practical information and research directly applicable to health care professionals providing post-acute and long term care.