Increase and change in pattern of hospital antimicrobial use, Denmark, 1997-2001

To analyse the changes and compare antimicrobial consumption in public hospitals in Denmark over the period 1997-2001.

Data on the number of WHO defined daily doses (DDD) were obtained from the Danish Medicines Agency. Data on the number of bed-days were obtained from the National Board of Health. We calculated antimicrobial consumption in hospitals as the number of DDD per 100 bed-days for all antibacterials for systemic use i.e. group J01 of the Anatomical Therapeutic Chemical (ATC) classification and for classes of this group.

During 1997-2001, antimicrobial use in hospitals in Denmark significantly increased by 18%, from 38.0 to 44.8 DDD per 100 bed-days (P < 0.005). Most of this increase (55%) was attributed to an increase in consumption of commonly used classes of antimicrobials, mainly penicillins with extended spectrum (ATC group J01CA), beta-lactamase-sensitive penicillins (J01CE) and beta-lactamase-resistant penicillins (J01CF). The 'broad-spectrum' and newer antimicrobials, i.e. combinations of penicillins with beta-lactamase inhibitor (J01CR), cephalosporins (J01DA), carbapenems (J01DH) and fluoroquinolones (J01MA) contributed to 36% of the increase. Together, these amounted to 16% of total consumption in hospitals in Denmark in 1997, rising to 19% in 2001.

Although antimicrobial consumption in public hospitals in Denmark is low compared with other countries, the steady increase and change in pattern of their use are causes of concern, deserving close monitoring and further investigations.