THE DEFINED DAILY DOSE PER 100 BED-DAYS AS A UNIT OF COMPARISON AND A PARAMETER FOR STUDYING ANTIMICROBIAL DRUG USE IN A UNIVERSITY HOSPITAL: A RETROSPECTIVE STUDY OF THE EFFECTS OF GUIDELINES AND AUDIT ON ANTIMICROBIAL DRUG USE

Growing awareness of problems arising from over-use of antimicrobial agents has led to attempts to develop policies or guidelines for rational treatment. To follow the effects of guidelines, the percentage of patients receiving antimicrobial drug therapy, acquired from patient records, has been a frequently used parameter. In this paper the Defined Daily Dose (DDD) per 100 bed-days has been used instead. This parameter can be calculated by converting the number of units of antimicrobials, delivered to individual wards, to defined daily doses per bed-day. This parameter determines the probability of treating a patient with a particular drug, based on pooled data. The DDD per 100 bed-days has been used to follow changes in prescribing habits arising from the acceptance of and adherence to guidelines over a period of 5 years in a University Hospital.