European Journal of Clinical Pharmacology

, Volume 39, Issue 3, pp 207–210

Measurement of drug use in a defined population

Evaluation of the Defined Daily Dose (DDD) methodology
  • A. Wessling
  • G. Boëthius

DOI: 10.1007/BF00315097

Cite this article as:
Wessling, A. & Boëthius, G. Eur J Clin Pharmacol (1990) 39: 207. doi:10.1007/BF00315097


To evaluate the accuracy of the DDD per 1000 inhabitants per unit time as an estimate of the fraction of drug users within a population, DDD figures have been compared with the proportion of apparent drug users, i.e. individuals in the population for who a prescriptions had been dispensed. An individual-based prescription monitoring project provided the necessary data for eight drugs representing continuous long-term medication, short-term medication and medication falling in between those two categories.

For digoxin, the long-term drug, the number of DDD/1000 inhabitants/day was about 40% below the proportion of apparent drug users. The DDD figure for antibiotics ranged from 4% below to 28% above the apparent users, and for the remaining drugs it ranged from 17% below (bendroflumethiazide, 1982) to 80% below (naproxen, 1985).

The DDD methodology is a valuable first step in overall drug use measurement, but for more precise estimates of drug use it must be supplemented by other techniques.

Key words

drug usedefined daily dose (DDD)estimation of drug useprescription monitoring

Copyright information

© Springer-Verlag 1990

Authors and Affiliations

  • A. Wessling
    • 1
    • 3
  • G. Boëthius
    • 2
  1. 1.National Corporation of PharmaciesStockholmSweden
  2. 2.Department of Pulmonary MedicineÖstersund HospitalÖstersundSweden
  3. 3.Department of Clinical Pharmacology of the Karolinska InstituteHuddinge University HospitalHuddingeSweden