Nursing Homes at Risk of Multi-Drug Resistant Organisms

Nursing home facilities could benefit from antibiotic stewardship programs to reduce the risk of multi-drug resistant organisms, according to new research.

A team, led by Kyle J. Gontjes, MPH, Division of Geriatric & Palliative Medicine, Department of Internal Medicine, University of Michigan Medical School, characterized antibiotic exposures in nursing home patient’s health care continuum and identified whether recent antibiotic exposure is linked to multidrug-resistant organism colonization and room environment contamination.

There is not much research into how hospital antibiotic prescribing habits contribute to multidrug-resistant organisms in nursing homes, which are ripe for negative outcomes.

“Nursing home patients are at a heightened risk for antibiotic-associated adverse events due to a convergence of patient-, facility-, and health care system–level risk factors,” the authors wrote.

Nursing Home Data

In the secondary analysis of a prospective cohort, the investigators examined 642 nursing home patients between 2013-2016 with 6 months of follow-up at 6 nursing homes in Michigan. The mean age of the patient population was 74.7 years and the median nursing home days to enrollment was 6.

Each patient was enrolled in the study within 14 days of administration.

The investigators performed clinical metadata abstraction, multi-anatomical site screening, and room environment surveillance for multi-drug resistant organisms at each study visit.

The team also abstracted antibiotic data from nursing home electronic medical records, which were then characterized by class, route, indication, location of therapy initiation, risk of Clostridiodes difficile infection, and 2019 World Health Organization (WHO) Access, Watch, and Reserve (AWARE) antibiotic stewardship framework categories.

Primary Outcomes

The investigators sought primary outcomes of multi-drug resistant organism colonization and room environment contamination at enrollment, measured using standard microbiology methods.

To identify the multi-drug resistant organism burden at nursing homes, caused by antibiotic exposure within 60 days of enrollment, the investigators used multivariable logistic regression.

Antibiotic exposure data was characterized using descriptive statistics.

Results

Within the study, the investigators found 65.7% (n = 422) received 1191 antibiotic exposures, 57.3% (n = 368) of which received 971 hospital-association prescriptions and 18.5% (n = 119) of which received 198 nursing home-associated prescriptions.

In addition, 44.1% (n = 283) of the patient population received at least 1 C diffogenic agent and 50.2% (n = 322) received at least 1 high-risk WHO AWARE antibiotic—either watch or reserve agents.

The investigators also found 56.7% (n = 364) of nursing home patients and 68.1% (n = 437) had multi-drug resistant organism-positive results at enrollment.

After conducting the multivariable analysis, the investigators found recent antibiotic exposure was positively linked to baseline multi-drug resistant organization colonization (OR, 1.70; 95% CI, 1.22-2.38) and multi-drug resistant organism environmental contamination (OR, 1.67; 95% CI, 1.17-2.39).

In addition, exploratory stratification by C diffogenic agent exposure increased the effect size (multi-drug resistant organism colonization: OR, 1.99; 95% CI, 1.33-2.96; multi-drug resistant organism environmental contamination: OR, 1.86l 95% CI, 1.24-2.79).

Similarly, exposure stratification based on exposure to high-risk WHO AWARE antibiotics also increased the effect size (multi-drug resistant organism colonization: OR, 2.32; 95% CI, 1.61-3.36; multi-drug resistant organism environmental contamination: OR, 1.86; 95% CI, 1.26-2.75).

“The findings of this study suggest that high-risk, hospital-based antibiotics are a potentially high-value target to reduce [multi-drug resistant organism] in post-acute care [nursing homes],” the authors wrote. “This study underscores the potential utility of integrated hospital and [nursing home] stewardship programming on regional [multi-drug resistant organism] epidemiology.”

The study, “Association of Exposure to High-risk Antibiotics in Acute Care Hospitals With Multidrug-Resistant Organism Burden in Nursing Homes,” was published online in JAMA Network Open.