Using a Difficult-to-treat Resistance Index to Gauge Imbalance between Countries’ Antibiotic Resistance Prevalence and Access to Antibiotics: A Scoping Review and Concept Proposal

The difficult-to-treat resistance (DTR) definition provides a global framework for assessing the impact of antimicrobial resistance on patient outcomes. A scoping review was conducted to understand the international adoption, scalability, and prognostic utility of DTR and to incorporate antibiotic access into the DTR framework. The study found that DTR was used in 57 studies across 94 countries, with 70% of them applying unmodified DTR definitions. The proposed DTRi could appraise the clinical impact of new agents, identify resistance-access imbalances, and optimize resource allocation to improve antibiotic resistance outcomes, particularly in under-resourced populations.