European Surveillance of Antimicrobial Consumption (ESAC): outpatient antibiotic use in Europe, 1998-2005
1. Vaccine and Infectious Disease Institute (VIDI), University of Antwerp, Belgium
2. National Centre for Antimicrobials and Infection Control, Statens Serum Institut (SSI, Danish Institute of Public Health), Copenhagen, Denmark
3. Since October 2007: European Centre for Disease Prevention and Control (ECDC), Stockholm, Sweden
The European Surveillance of Antimicrobial Consumption (ESAC) project collects data on antimicrobial consumption in ambulatory care and hospital settings from 34 European countries. This paper provides data on outpatient antibiotic use in Europe as well as an analysis of trends for the period 1998-2005 in 28 participating countries.
Data have been collected since 1997, in accordance with the Anatomic Therapeutic Chemical (ATC) classification and the Defined Daily Dose (DDD) measurement unit . The 2004 version of the ATC/DDD was used for 1997-2003 data, version 2005 for 2004 data and version 2006 for 2005 data . For standardisation, data on antibiotic use (antimicrobials for systemic use, ATC Group J01) were reported as DDD per 1,000 inhabitants and per day (DID).
In 2005, reliable data on outpatient antibiotic use were delivered by 28 countries. Bulgaria, Greece and Iceland reported data on total use, i.e. use in ambulatory care and hospitals combined. The overall consumption of antibiotics varied from 9.2 in the Russian Federation (only ambulatory care) to 34.7 DID in Greece (total use, including hospital care). The median for countries reporting only ambulatory care data was 18.1 DID (Figure 1A).
Figure 1B presents the relative use of the most important antibiotic classes. The antibiotic class used most was ‘penicillins’, with a proportion of 45% or more in half of the countries. The second most used class was either ‘macrolides-lincosamides-streptogramins’ or ‘tetracyclines’, except for five countries, where it was either ‘cephalosporins and other beta-lactams’ (Belgium, Croatia, Israel and Luxembourg) or ‘sulfonamides and trimethoprim’ (the Russian Federation).
From 1998 to 2005, at least one year of reliable data on outpatient antibiotic use was provided by 29 countries. Among those 29 countries, 18 reported data for each year of the whole surveillance period (Figure 2). Reports for the year 1998 were received from 20 countries, and 28 countries reported data for 2005. A comparison of the data from 2005 with those from previous years did not show any major differences in the ranking of the countries with respect to total antibiotic use, nor in the relative use of the different antibiotic classes. In Greece (where the data for 2004 and 2005 include hospital use) as well as in Croatia, Denmark, and Ireland, outpatient antibiotic use increased, while a decrease was seen in six countries: Belgium, the Czech Republic, France, Slovakia, Slovenia, and Sweden.
The observed trends in outpatient antibiotic use expressed in DID are most likely due to true changes in the frequency of antibiotic prescribing and in exposure to antibiotics in the general population. Most countries provided data from the same source during the eight year study period. Additionally, the methodological bias caused by the use of the 2004, 2005 and 2006 versions of the ATC/DDD Index is very limited, since these versions did not differ with respect to the DDD assignment for important substances. New DDDs were only assigned for new and less used drugs. Recent data reported from Greece for the years 2004 and 2005 include antibiotic use in both outpatient and hospital care. Previous data from ESAC show that antibiotic use in hospitals in European countries in 2002 was around 2 DID on average and 2.2 DID in Greece . A rough estimation of outpatient antibiotic use by subtracting average hospital use from total use shows that outpatient antibiotic use in Greece was indeed the highest in Europe in 2004 and 2005.
Many countries were similar in their short- or long-term variations of antibiotic use. Firstly, the use of antibiotics in 2004 was lower than in 2003 in many countries. This could partly be explained by the absence of a major influenza epidemic during that calendar year in these countries [4,5]. Secondly, in 10 out of the 29 countries that reported at least one year of reliable data, outpatient antibiotic use increased or decreased in the period from 1998 to 2005. However, trends in antibiotic use expressed in DID may not fully reflect trends in the frequency of antibiotic prescriptions. In Belgium, for instance, changes in prescribing practice led to a higher DID due to an increased dosage of certain prescriptions: the dosage of amoxicillin or amoxicillin-clavulanic acid was increased in order to eradicate S. pneumoniae not susceptible to penicillin, and fluoroquinolones started to be used less for the treatment of urinary tract infections and more for the treatment of respiratory tract infections, which requires a higher dosage. Therefore, the number of prescriptions may have decreased more than the DID values indicate, and the impact of public health campaigns in decreasing exposure of the population to antibiotics may be underestimated .
Reliable, longitudinal data on antibiotic use from an established surveillance system allows a comparison of countries and assessment of trends in Europe. Several countries have reported long term increasing or decreasing trends in outpatient antibiotic use. Interestingly, of the six countries with a decreasing trend during the study period, four had implemented a national programme to control antimicrobial resistance and to improve the rational use of antibiotics. This included media coverage, such as national public campaigns in Belgium and France, and repeated media reports in Slovenia and Sweden [6-8]. Some of these countries are already seeing a decrease in antibiotic resistance among bacteria commonly responsible for community-acquired infections [9,10].
Awareness about antimicrobial resistance should be raised in all European Union (EU) Member States, particularly in those countries with high antibiotic use and resistance. On 16 October 2007, the European Centre for Disease Prevention and Control (ECDC) will organise a debate at the European Parliament on the role of the EU on these issues. In 2008, ECDC will organise the first European Antibiotic Resistance Day to promote and coordinate initiatives to raise public awareness on antimicrobial resistance and appropriate use of antibiotics in the EU.
# The European Surveillance of Antimicrobial Consumption (ESAC) is an international project aimed at the collection of comparable and reliable antibiotic use data in all European countries. ESAC was funded by DG/SANCO of the European Commission from November 2001 until April 2007. ESAC recently won a Call for Proposals from the ECDC to perform surveillance of antimicrobial consumption in Europe for a period of three years starting in September 2007. It will continue to collect and make publicly available data on the use of antimicrobials in Europe. More information is available at: http://www.esac.ua.ac.be
The ESAC Project Group members contributing to the collection of the 1997-2005 use data were Helmut Mittermayer, Sigrid Metz (Austria); Herman Goossens (Belgium); Boyka Markova (Bulgaria); Arjana Andrasevic, Igor Francetic (Croatia); Despo Bagatzouni (Cyprus); Jiri Vlcek (Czech Republic); Dominique L. Monnet, Arno Muller, Annemette Anker Nielsen (Denmark); Ly Rootslane (Estonia); Pentti Huovinen, Pirkko Paakkari (Finland); Philippe Cavalié, Didier Guillemot (France); Winfried Kern, Helmut Schroeder (Germany); Helen Giamarellou, Anastasia Antoniadou (Greece); Gabor Ternak, Ria Benko (Hungary); Karl Kristinsson (Iceland); Robert Cunney, Ajay Oza (Ireland); Raul Raz (Israel); Giuseppe Cornaglia (Italy); Sandra Berzina (Latvia); Rolanda Valinteliene (Lithuania); Robert Hemmer, Marcel Bruch (Luxembourg); Michael Borg, Peter Zarb (Malta); Robert Janknegt, Margreet Filius (the Netherlands); Hege Salvesen Blix (Norway); Waleria Hryniewicz, Pawel Grzesiowski (Poland); Luis Caldeira (Portugal); Irina Codita (Romania); Svetlana Ratchina (Russia); Viliam Foltan, Tomas Tesar (Slovakia); Milan Cizman (Slovenia); José Campos, Edurne Lazaro, Francisco de Abajo (Spain); Otto Cars, Gunilla Skoog, Sigvard Mölstad (Sweden); Giuliano Masiero (Switzerland); Serhat Unal (Turkey); Peter Davey, Faranak Ansari (UK). Italian data for 2004 and 2005 were provided by the National Observatory on Medicine Use (OSMED).
Arno Muller was employed at the Statens Serum Institut in Copenhagen, Denmark, at the time of data collection. Samuel Coenen is a Postdoctoral Fellow of the Research Foundation-Flanders in Brussels, Belgium.