Antibiotic use varies substantially among adults: a cross-national study from five European Countries in the ARITMO project.

Purpose: To examine patterns of outpatient and community antibiotic use among adults in five European countries.

Methods: We used healthcare data of 28.8 million adults from six population-based ARITMO project databases to ascertain information on systemic antibiotic use in Denmark (2000-2008), the Netherlands (1999-2010), Italy (2000-2010), the UK (1996-2009), and Germany (2004-2008). We estimated overall, and age-group and sex specific antibiotic use as defined daily doses (DDD) per 1000 inhabitants per day. We computed annual age- and sex-standardized population prevalence of antibiotic use per 1000 persons-years (p-y) and the mean duration (in days) of antibiotic use.

Results: The overall antibiotic use varied from 8.7 DDD per 1000 inhabitants per day in the UK to 18.1 DDD in Denmark, representing a 2.1-fold geographical variation. In all countries, prescribing was relatively high among individuals aged 15-19 years; lower in those aged 20-50 years; and then increased steadily reaching 41.8 DDD per 1000 inhabitants per day in individuals ≥ 85 years in Denmark. After age- and sex-standardization, prevalence of antibiotic use varied threefold from 160.2/1000 p-y in the UK to 421.1/1000 p-y in Italy. The ratio of broad- to narrow-spectrum penicillin, cephalosporin, and macrolide use varied from 0.6 in Denmark to 120.2 in Italy. Women used more antibiotics than men did in all countries. Across countries, the mean duration of antibiotic use varied 1.3 to 21.1-fold for different antibiotics.

Conclusions: Antibiotic use is high in women and the elderly. Prescribing patterns vary substantially across European countries, both according to overall consumption, user prevalence, duration, and narrow- versus broad-spectrum antibiotics.