Overview of Methods for Assessing Antimicrobial Use in Outpatient Settings in High-Income Countries: A Narrative...

Background/Objectives: Over 80-90% of antibiotics are used in outpatient settings, where interactions among diverse prescribers, dispensers, and patients create complex usage patterns. The study examines how outpatient antimicrobial use is monitored in high-income countries (HICs), focusing on data sources and their relevance for stewardship and surveillance. Methods: This narrative review searched MEDLINE and Embase for English-language studies reporting outpatient antimicrobial use in HICs (from inception to 2023), supplemented by reference screening, targeted Google web searches, and expert input. Studies were categorized by data collection method, study period, and WHO Region. Key characteristics such as patient group, disease focus, country, dataset, and reported outcome measures were also extracted and tabulated. Results: We identified 287 studies, of which 79 met inclusion criteria. Most (n = 76) were conducted after 2000 and spanned all four WHO regions with HICs. Of the 73 studies using surveillance databases, six types were identified: dispensing (n = 13), health insurance (n = 24), GP prescribing (n = 17), commercial (n = 9), procurement (n = 3), and multinational networks (n = 7). Six studies used surveys: general point prevalence (n = 1), indication-specific audits (n = 3), patient exit interviews (n = 1), and community surveys (n = 1). Common outcome measures included DID, Days of Therapy, and patterns of antimicrobial use by season, age, sex, indication, and prescriber. Of the 48 studies published after 2018, nine reported using AWaRe metrics. Conclusions: Surveillance databases were the main method for tracking outpatient antimicrobial use in HICs; surveys were less common. Antibiotic use has increasingly been reported by AWaRe category, especially in prescribing and insurance studies. Further indicators and tech-driven tools are needed to support stewardship.