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 monitoring and 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

ATC/DDD Methodology Questionnaire: We Need Your Input!

We kindly invite you to participate in a WHO-led questionnaire focused on the implementation and usage of the ATC/DDD methodology. Your insights will help improve the system and shape future developments. It should take approximately 20 minutes to complete the questionnaire. Responses are requested by 15 November 2024. Click the link to participate and share with your colleagues!

Questionnaire on ATC/DDD Methodology Implementation and Usage (office.com)