International language for drug utilization research
The Anatomical Therapeutic Chemical (ATC) classification system and the Defined Daily Dose (DDD) as a measuring unit have become the gold standard for international drug utilization research.
The ATC/DDD system is a tool for exchanging and comparing data on drug use at international, national or local levels.
Welcome to the WHO Collaborating Centre for Drug Statistics Methodology
Last updated: 2015-05-05