Definitions and comparability for the indicators are taken directly from the OECD report Health at a Glance 2017: OECD indicators. Detailed information about the definitions and the source and methods for each country can be found here.
Defined daily dose (DDD) is the assumed average maintenance dose per day for a drug used for its main indication in adults. DDDs are assigned to each active ingredient(s) in a given therapeutic class by international expert consensus. DDDs do not necessarily reflect the average daily dose actually used in a given country.
Data for Spain, United Kingdom, Portugal and Sweden include data for primary care physicians only. Data for Canada, Ireland and New Zealand include only those dispensed by community pharmacies. Data for Finland and Italy include outpatients only. Data for Australia include prescriptions dispensed at community pharmacies, private hospital pharmacies and public hospital outpatients and admitted day patients. Results for Canada only include data from the provinces of British Columbia, Manitoba and Saskatchewan.
Denominators comprise the population held in the national prescribing database, rather than the general population.