Coding and classification in drug statistics – From national to global application

Abstract

SUMMARY

The Anatomical Therapeutic Chemical (ATC) classification system and the defined daily dose (DDD)

was developed in Norway in the early seventies. The creation of the ATC/DDD methodology was an

important basis for presenting drug utilisation statistics in a sensible way. Norway was in 1977 also the

first country to publish national drug utilisation statistics from wholesalers on an annual basis. The

combination of these activities in Norway in the seventies made us a pioneer country in the area of drug

utilisation research. Over the years, the use of the ATC/DDD methodology has gradually increased in

countries outside Norway. Since 1996, the methodology has been recommended by WHO for use in

international drug utilisation studies. The WHO Collaborating Centre for Drug Statistics Methodology

in Oslo handles the maintenance and development of the ATC/DDD system. The Centre is now responsible

for the global co-ordination. After nearly 30 years of experience with ATC/DDD, the methodology

has demonstrated its suitability in drug use research. The main challenge in the coming years is to

educate the users worldwide in how to use the methodology properly.