Antimicrobial use and stewardship activities in Swiss long-term care facilities: data from a national point-prevalence survey

BACKGROUND: The first nation-wide point-prevalence survey (PPS) in Swiss long-term care facilities (LTCF) showed significant geographical differences in antimicrobial use. The aim of this study was to characterize these variations, identify associated factors, and assess antimicrobial stewardship (AMS) practices. METHODS: The PPS was performed in September 2024. A sample of Swiss LTCFs was randomly selected for representativeness according to language region and size. The PPS was also open to all interested Swiss LTCFs. Data were collected using the adapted Healthcare-Associated Infections in European Long-Term Care Facilities (HALT)-4 protocol. Data on antimicrobial use and AMS elements were stratified by language region. To identify factors independently associated with antimicrobial use, multivariable logistic regression was performed including resident- and institution-level variables. RESULTS: The sample included 7244 residents from 94 LTCFs (43 from German, 18 from French, and 33 from Italian language regions). Most common indications for antimicrobial treatment were urinary tract infections, respiratory tract infections and skin or soft tissue infections, across all language regions. Antimicrobial prophylaxis (32% 67/209) was more common in the French (41%, 26/64) compared to the Italian (29%, 24/82) and German language regions (27%, 17/63). Most commonly prescribed substances for prophylaxis were trimethoprim/sulfamethoxazole, nitrofurantoin and amoxicillin/clavulanic acid. Adoption of AMS elements was low and more common in the French and Italian language region. In multivariable analysis, residing in a LTCF from the French language region remained the strongest factor associated with antimicrobial use (adjusted odds ratio [aOR] 2.99, 95% CI 1.76-5.01). Further factors were recent hospitalisation or surgery (aOR 2.19, 95% CI 1.50-3.19), urinary catheter use (aOR 2.10, 95% CI 1.36-3.24) and use of proton pump inhibitor (aOR 1.49, 95% CI 1.11-2.00), but not the number of implemented AMS elements. CONCLUSIONS: Antimicrobial use in Swiss LTCF is higher in the French compared to the Italian and the German language region, independent of other factors. These findings highlight the need for regional surveillance, AMS interventions tailored to local epidemiology, and assessment strategies for their implementation and effectiveness. The high proportion of prophylactic antimicrobials warrants further investigation to determine underlying causes and represents a target for AMS interventions.