Increased antibiotic use in Norwegian hospitals despite a low antibiotic resistance rate

Objectives: Although antibiotic use and resistance are low in Norway, the situation risks changing for the worse. We investigated trends in antibiotic use and assessed them in relation to antibiotic resistance in Norway. Methods: We drew on hospital pharmacy sales data to record antibiotic use from 2002 to 2007 in eight hospitals serving 36% of the nation's population. Antibiotic use was measured using different indices with defined daily doses (DDDs) as the numerator (WHO ATC/DDD classification). Results: Total antibiotic use increased from 1.02 to 1.30 DDDs/1000 inhabitants/day (DIDs) and from 61.7 to 72.4 DDDs/100 bed-days (BDs) (17.4%); related to the number of discharges, no significant DDD change was shown. Their use in core units (adult intensive care units, recovery/post-operative wards and departments of internal medicine and surgery with all subspecialties) increased from 64.1 to 80.8 DDDs/100 BDs (26.1%) and by 3.1% related to the number of discharges. The total use of broad-spectrum antibiotics increased by 47.9% when measured as DDDs/100 BDs, and by 19.1% based on the number of discharges; the corresponding figures for core units were 60.5% and 31.2%, respectively. Conclusions: There was a substantial increase in total antibiotic use, and an even more pronounced increase in the use of broad-spectrum antibiotics, which seems unjustified considering the current low antibiotic resistance in Norway.