From population to individuals: a new indicator for evaluating the appropriateness of clinical application of antibiotics.

BACKGROUND: This study aims to establish a new indicator based on the anatomical therapeutic chemical/defined daily dose (ATC/DDD) system.

METHODS: Utilization data of antibiotics of inpatients in a university hospital were used to calculate the indicators of use rate (UR), use density (UD), and ratio of use density to use rate (UD/UR). According to the professional characteristics, the recommended values of UD/UR in different departments were established respectively. Crosswise comparison and appropriateness evaluation between different treatment groups with the same profession were performed. For individual inpatients with abnormally increased drug utilization index (DUI) and ratios of antimicrobial course to length of stay (C/S), detailed analysis was performed to examine whether any irrational drug utilization occurred.

RESULTS: The indicator UD/UR combines both dose and duration of treatment, which were the two main factors affecting the appropriateness of clinical application of antibiotics. Thus, it can more sensitively reveal the drug utilization of inpatients receiving antibiotics. UD/UR is also more suitable for evaluating the clinical appropriateness of antibiotic application than the macroscopic indicator, total UD, and could be applied at the macroscopic and microscopic levels.

CONCLUSIONS: The ratio UD/UR has great practical value and can serve as a reference for evaluating the appropriateness of clinical application of antibiotics.