Patterns of antibiotic use and expenditures during 7 years at a university hospital

Before 1982, annual retrospective drug-use audits clearly established the pattern of increased antibiotic use and expenditures at the University of Minnesota Hospital. At that point, a concurrent trend analysis system was developed to track this use by individual drug and therapeutic class, to identify trends in use for qualitative evaluation, and to provide an assessment of any intervention intended to alter use. Monthly use of all injectable antibiotics and antifungal agents, and selected oral antifungals has been tracked since 1982 as both defined daily doses and dollars. Use patterns in 1981 served as baseline. The defined daily dose index, which captures changes associated with intensity of antibiotic use per patient, increased 62% from baseline through 1988. This increase, however, resulted in a disproportionate 228% rise from baseline in antibiotic expenditures to nearly $3 million/year for 1988. The defined daily dose index peaked in 1985, declined in 1986, and remained stable for 1987 and 1988. Qualitative drug-use review programs were associated with this positive change. These results demonstrate the utility of concurrent trend analysis as a resource-management tool and as a measure of effectiveness for collaborative physician-pharmacist programs to foster safe, appropriate, and economical use of antiinfective agents.