Regional variation in the use of antibiotics in four Danish hospitals.

The increasing use of antibiotics contributes to the selection of resistant bacteria and to the cost of health care. Large regional differences in the use of antibiotics between and within countries exist. This study describes such usage in four Danish hospitals, and includes a comparison with that of the average of 450 US hospitals. Compared to the Danish hospitals, the US hospitals used approximately double the amount of antibiotics in defined daily dosages (DDD)/100 bed days. In contrast to the comparison with the American hospitals no real differences were found comparing the four Danish hospitals. The four Danish hospitals differed in degree of specialization, presence of a clinical microbiological department or a hospital pharmacy. Use of antibiotics, in DDD/100 bed days, was highest in the hospital without a department of clinical microbiology, while the highest cost of antibiotics/admission was found in the hospital with the highest degree of specialization. Restraint in antibiotic usage calls for the joint efforts of the department of clinical microbiology, the hospital pharmacy and the local drug committee - the most important tools being: continuous education, audits of antibiotic use, provision of guidelines and recommendations, facilities for rapid diagnosis of infectious diseases, and limitation of the number of antibiotics used in routine sensitivity testing.