Guidelines for ATC classification and DDD assignment - WHOCC

TABLE OF CONTENTS
I. Introduction ........................................................................................... 10
A. History of the ATC/DDD system.................................................... 10
B. Present Organisational responsibility for the ATC/DDD system ... 11
1. WHO Collaborating Centre for Drug Statistics Methodology .. 11
2. WHO International Working Group for Drug Statistics
Methodology ............................................................................. 12
C. The purpose of the ATC/DDD system............................................ 14
II. The anatomical therapeutic chemical (ATC) classification system .. 15
A. Structure and nomenclature............................................................. 15
B. Inclusion and exclusion criteria....................................................... 16
C. Principles for classification ............................................................. 16
1. General Principles ..................................................................... 16
2. Classification of plain products ................................................. 18
3. Classification of combination products ..................................... 19
D. Principles for changes to ATC classification .................................. 20
E. The EphMRA classification system................................................ 21
III. DDD (Defined Daily Dose).................................................................... 22
A. Definition and general considerations............................................. 22
B. Principles for DDD assignment....................................................... 23
1. Plain products ............................................................................ 23
2. Combination products................................................................ 25
3. Other factors ........................................................................... 26
a) Fixed dose groups ................................................................... 26
b) Depot formulations ................................................................. 26
c) Intermittent dosing .................................................................. 26
d) Duration of treatment .............................................................. 27
4. Selection of units ....................................................................... 27
C. Pediatric DDD................................................................................. 28
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