Antibiotic consumption patterns in older adults: a comparative study of people 65 years and older in and outside nursing homes, Belgium, 2016 to 2022.

BackgroundInappropriate antimicrobial consumption (AMC) drives the emergence of antimicrobial resistance. Institutionalised, older populations are associated with antimicrobial treatments of longer duration and broader spectrum than recommended, higher rates of multidrug-resistant infections and poorer outcomes for resistant infections. Yet systematic, national monitoring of AMC in nursing home (NH) residents is lacking.AimTo perform a retrospective analysis of antibiotic consumption in Belgian NHs, we compared analogous populations inside and outside NHs. We aimed to provide a blueprint for establishing surveillance of NH AMC, based on national reimbursement data.MethodsThe National Institute for Health and Disability Insurance supplied reimbursement AMC data for outpatients from 2016 to 2022. Data were classified by the Anatomical Therapeutic Chemical system, expressed as defined daily doses (DDD) and aggregated by prescription month, patient age, sex and residency inside/outside a NH. The number of ensured beneficiaries, aggregated by the same demographic variables, was collected from the Intermutualistic Agency. We compared the DDDs per 1,000 beneficiaries per day, along with secondary metrics for national and international targets for analogous populations inside and outside NHs.ResultsTotal antibiotic consumption decreased in both populations but remained twofold higher in NH residents. Proxy prescription quality metrics were consistently less favourable within NHs and diverged further during the COVID-19 pandemic. Distinct consumption patterns and greater seasonal fluctuations were observed in NH residents.ConclusionGiven the different infection risks and higher antibiotic consumption of NH residents, AMC surveillance and antimicrobial stewardship efforts targeting this fragile population are needed.