The equity gap in precision dosing: a cross-sectional analysis of hospital-wide antimicrobial therapeutic drug monitoring implementation

Background: Therapeutic Drug Monitoring (TDM) is pivotal for optimizing antimicrobial efficacy and managing drug-resistant infections. However, its real-world implementation patterns, particularly the heterogeneity in initial hospital-wide application within large Chinese general hospitals, have not been systematically evaluated. Methods: This retrospective study was conducted in a representative Chinese tertiary hospital to assess its hospital-wide antimicrobial TDM program launched in June 2024. The analysis included 2,316 plasma drug concentration measurements from 1,928 inpatients between October and December 2024, primarily evaluated based on trough concentrations. Results: The study revealed significant inter-departmental heterogeneity in TDM implementation. Utilization was high in intensive care units (e.g., EICU: 91.95%) and infection-related departments, but critically low in non-intensive care settings (e.g., Pediatrics: 0%). Overall, only 50.3% of drug concentrations were within the therapeutic range, with time-dependent antimicrobials (e.g., piperacillin attainment: 31.47%) performing significantly worse than concentration-dependent agents (e.g., moxifloxacin attainment: 86.09%). Subtherapeutic concentrations were predominantly clustered in hematology patients, while supratherapeutic concentrations were concentrated in ICUs. The study also demonstrated the inadequacy of a trough concentration-based monitoring strategy for addressing the complex pharmacokinetics in critically ill patients. Conclusion: This study provides a critical snapshot of the heterogeneous implementation and systemic inequities in the initial rollout of a hospital-wide antimicrobial TDM program. The findings highlight a significant gap between specialized technique and equitable public health practice. Addressing these implementation disparities requires tailored strategies, multidisciplinary collaboration, and refined monitoring approaches to optimize antimicrobial stewardship and ensure all patients benefit from precision dosing.