Functional Disability and Nursing Resource Use Are Predictive of Antimicrobial Resistance in Nursing Homes

OBJECTIVES: To use a simple measure of activities of daily living, wounds, and indwelling devices (urinary catheter, feeding tube) to predict prevalent, new, and intermittent multidrug-resistant organism (MDRO) acquisition in nursing home (NH) residents. DESIGN: Secondary analysis, prospective cohort study. SETTING: Southeast Michigan NHs (n = 15). PARTICIPANTS: NH residents (N = 111, mean age 81) with two or more monthly visits (729 total). MEASUREMENTS: Monthly microbiological surveillance for MDROs from multiple anatomic sites from enrollment until discharge or 1 year. The Arling scale, previously developed as a measure of NH residents' need (time-intensity) for nursing resources, was used to predict prevalent and time to new or intermittent acquisition (months) of methicillin-resistant Staphylococcus aureus (MRSA), vancomycin-resistant enterococci (VRE), and antibiotic-resistant gram-negative bacteria (R-GNB) colonization using multiple-failure accelerated time-factor survival analysis, controlling for comorbidity, hospitalization, and antibiotic use in the prior month. RESULTS: One-fifth of participants had a wound, and one-third had a device. There were 60 acquisitions of MRSA, 56 of R-GNB, and 15 of VRE. Expected time to acquisition was less than 1 year for MRSA (median 6.7 months) and R-GNB (median 4.5 months) and more than 1 year for VRE (median 40 months). Arling score was associated with earlier new MRSA and VRE acquisition. A resident with only mild functional impairment and no device or wound would be expected to acquire MRSA in 20 months, versus 5 months for someone needing the most-intense nursing contact. CONCLUSION: MDRO acquisition is common in community NHs. Need for nursing care predicts new MDRO acquisition in NHs, suggesting potential mechanisms for MDRO acquisition and strategies for future interventions for high-risk individuals (e.g., enhanced barrier precautions).