Guidelines for ATC classification and DDD assignment - WHOCC

PREFACE
The Anatomical Therapeutic Chemical (ATC) classification system and the Defined
Daily Dose (DDD) as a measuring unit are recommended by the WHO for drug
utilization studies. The system is now widely used internationally and the number of
users is gradually increasing. The purpose of preparing guidelines is to make
information about the ATC classification system and the DDD methodology available
to the users.
The members of the WHO International Working Group for Drug Statistics
Methodology have given expert advice and comments on the work with these
guidelines.
This 14th edition of the Guidelines for ATC classification and DDD assignment is
based on the ATC classification index with DDDs valid from January 2011. The
ATC index with DDDs, which is important for the understanding of these guidelines,
is available on request from the WHO Collaborating Centre for Drug Statistics
Methodology (order form, see Annex II). A searchable version of the index is
available on our website www.whocc.no. The ATC index with DDDs is updated
annually. Please be aware that Spanish versions of the ATC/DDD publications also
are available.
An integrated version of the Guidelines for ATC classification and DDD assignment
and ATC classification index with DDDs is available on internet. For further
information, please see our website: www.whocc.no.
All comments connected to the assignment of DDDs are given in shadowed boxes in
the various chapters to each ATC group.
We hope this book will prove helpful to the users of the ATC/DDD system.
Suggested improvements can be addressed to the WHO Centre in Oslo.
Oslo, December 2010
Hanne Strøm
Director
WHO Collaborating Centre for Drug Statistics Methodology
Norwegian Institute of Public Health