Antibiotic prescriptions in Lombardy Region according to WHO AWaRe classification: trend from 2000 to 2024.

Antimicrobial resistance represents a significant threat to public health. The aim of the study was to examine trends in antibiotic prescription in Lombardy and to assess the prevalence and patterns according to the WHO AWaRe classification. This retrospective cohort study was based on healthcare utilization databases from the Lombardy Region, Italy. Residents between 2000 and 2024 who had at least one antibiotic prescription were included. Patients with antibiotic prescription were categorized into the three groups of the WHO AWaRe classification - Access, Watch, and Reserve. To assess temporal trends in the AWaRe classification, we performed a multinomial logistic regression analysis adjusted for sex, age, year and Local Health Services. We recorded more than 148 million antibiotic prescriptions. The total annual prescriptions slightly decreased during the study period and the classes most prescribed were combinations of penicillins (28.5%), macrolides (19.3%) and fluoroquinolones (17.4%).Watch antibiotics accounted for 56.5% of all prescriptions, and Access for 43.5%. An increasing of the proportion of Access prescriptions and a corresponding reduction in the prescription of a Watch antibiotic was observed over time (p < 0.0001). Watch prescriptions varied slightly across local health services, from 54% to 61% of the total prescriptions. Watch antibiotics were prescribed more frequently with increasing age: 41.0% in children, 55.7% in adults, 65.8% in older adults and 71.8% in oldest old. Levels of Access antibiotics remained well below the WHO threshold (60%). Prescribing patterns were largely homogeneous across local health services and appeared to be influenced more by local prescribing practices than by overall antibiotic consumption. Older adults and oldest old were largely exposed to Watch antibiotics, underscoring the need for targeted antimicrobial stewardship strategies in this population. Continued surveillance using the WHO AWaRe framework, monitoring and trend analysis of antibiotic prescriptions may reinforce the optimization and appropriateness of community antibiotic prescribing. Furthermore, it can support clinicians and healthcare policymakers in implementing guidelines aimed at limiting the emergence and spread of antimicrobial resistance.