Data collection and analysis

The European Surveillance of  Antimicrobial Consumption Network (ESAC-Net) continues collecting reference data on the consumption of antimicrobials for systemic use in the community and in the hospital sector in EU and EEA/EFTA countries through the European Surveillance System (TESSy).

The former ESAC subprojects that collected data on antimicrobial use in hospitals and in long-term care facilities are continued by ECDC within the following activities of the Healthcare-Associated Infections Surveillance Network (HAI-Net): 

• Data on the prevalence of antimicrobial use in patients from European acute care hospitals will be provided through the ECDC-coordinated, Europe-wide point prevalence survey of healthcare-associated infections and antimicrobial use;
• Data on the prevalence of antimicrobial use in residents at long-term care facilities will be collected by the ECDC-funded HALT-2 project.  

What surveillance data will be collected? 

ECDC will continue to produce comparable surveillance data on antimicrobial consumption in the community and in the hospital sector in EU and EEA/EFTA countries. The data sources will be national sales and reimbursement data, including information from national drug registers.

The WHO Anatomical Therapeutic Chemical (ATC) classification system will be used for the allocation of antimicrobials into groups.

ECDC will collect data at national level and intends to collect sub-national data based on the NUTS classification.

Data on antimicrobial consumption will be collected at the product level and the antimicrobials under surveillance will be:

• Antibacterials for systemic use (ATC group J01);
• Antimycotics for systemic use (ATC group J02);
• Antimycobacterials (ATC group J04);
• Antivirals for systemic use (ATC group J05)

In addition, a few other antimicrobials outside of ATC group J will also be collected to complete the picture of antimicrobial consumption in Europe.

How will the data be collected, processed and expressed? 

Antimicrobial consumption in Europe is monitored by a network of national surveillance networks in the EU and EEA/EFTA countries through annual data calls.

The national networks will upload the data to a central database (The European Surveillance System - TESSy) maintained at ECDC. After uploading, each country will approve its own data and the results will be made available from the ECDC website.

Antimicrobial consumption data from EU and EEA/EFTA countries will be expressed as a number of WHO Defined Daily Doses (DDD) per 1,000 inhabitants and per day.

Complementary to this measurement unit, the number of packages per 1,000 inhabitants and per day will also be reported depending on the availability of data on packages from the national surveillance networks. Information on packages is deemed to improve the understanding and interpretation of differences in the levels and trends in antimicrobial consumption observed between and within countries, as the ATC/DDD system cannot take into account changes in package content.

For the denominator, population data from EUROSTAT, or from national statistic reports, will be used. When consumption data do not cover the whole population, countries will provide data on the population covered by antimicrobial consumption surveillance data.

To maintain and facilitate data reporting, ECDC will ensure:

• Validation of community and hospital sector data, including data from the national drug registers derived from national surveillance networks;
• Analysis of the trends in antimicrobial consumption overall and in the different ATC groups, as well as comparisons between countries and regions;
• Public access to information on antimicrobial consumption in Europe through an ESAC-Net interactive database.