Objective: The aim of this article is to present and compare the different methods used to study drug consumption.
Methods: Particular attention is given to one method, the defined daily dose (DDD), for antibiotic dispensation data in Toulouse University Hospital Centre between 2001 and 2003.
Results: Data, expressed in units of packaging, were converted into grams of active substance and then to number of DDD. The number of hospitalization days was used to calculate the penetration index (ratio of number of DDD to the number of hospitalization days). Penetration indexes were similar for each year of study period: 60.6 for 100 patient-days in 2001, 67.7 in 2002 and 66.6 in 2003 (p = 0.37). The most prescribed class was penicillin, most often amoxicillin.
Conclusion: Use of DDD methodology and penetration index is an accessible and simple tool for monitoring consumption of antibiotics as well as other drugs.