Surveillance of Antimicrobial Consumption |
|---|
In Hospital Sector |
2024 |
Key Points
In 2024, a total of 44 hospitals participated in AMC surveillance. Antimicrobial consumption across these hospitals ranged from 29.9 to 97.6 DDD per 100 BDU.
The rate of J01 antimicrobial consumption in the hospital sector was 78.4 DDD per 100 BDU in 2024, representing a small increase compared with 77.7 in the previous year.
The most commonly used agents were penicillins; other beta-lactams (including cephalosporins, carbapenems, and monobactams); and other antibacterials such as intravenous vancomycin, intravenous metronidazole, linezolid, nitrofurantoin, and daptomycin. These were followed by macrolides, tetracyclines, aminoglycosides, and quinolones.
The relative consumption of parenteral antibiotics has fluctuated between 60–65% over the past five years. In 2024, it decreased to 59.0%, down from 63.6% in the previous year.
Consumption based on WHO AWaRe categories showed a decrease in the relative use of the Access group, which accounted for 52.4% of consumption in 2024 compared with 53.9% in 2023. The consumption of Reserved group antimicrobials remained stable over the past two years at 3.9%.
Analysis by the AMRIC Green/Red classification showed little change in the relative consumption of green, amber, and red agents over the past five years. Green agents accounted for around 29% of use, amber agents for around 64%, and reserved agents fluctuated between 5–6%.
Methodology
Background
ESAC-Net (European Surveillance of Antimicrobial Consumption Network) is a Europe-wide network of national surveillance systems, providing European reference data on antimicrobial consumption. ESAC-Net collects and analyses data on antimicrobial consumption from EU and EEA countries, both in the community and in the hospital sector. The collected data are used to provide timely information and feedback to EU and EEA countries on indicators of antimicrobial consumption. These indicators provide a basis for monitoring the progress of EU and EEA countries towards prudent use of antimicrobials. The Health Protection Surveillance Centre (HPSC) participates in ECDC’s ESAC-Net on behalf of Ireland and has been collecting, analysing, and sharing antimicrobial consumption data in the hospital sector since 2004. In addition to sharing this data with ECDC, HPSC also prepares hospital feedback reports for each acute inpatient hospital. These reports enable hospitals to monitor their local antimicrobial consumption and benchmark their performance against national and hospital group results.
ATC/DDD Methodology
Antimicrobial consumption data are calculated by using Anatomical Therapeutic Chemical (ATC) and Defined Daily Doses (DDD) methodology. The purpose of the ATC/DDD system is to serve as a tool for drug utilization monitoring and research in order to improve quality of drug use. One component of this is the presentation and comparison of drug consumption statistics at international, national and other levels.
The ATC system classifies every drug based on where it acts in the body, what it treats, how it works, and its chemical structure. This ensures that all countries or researchers refer to the same drug in the same way, regardless of brand names or local terms. The ATC classification system organizes drugs into five hierarchical levels based on their therapeutic use and chemical characteristics. Taking amoxicillin as an example, its ATC code is J01CA04. The first level, represented by the letter J, indicates that the drug belongs to the anatomical main group “anti-infectives for systemic use.” The second level, J01, classifies it as an antibacterial for systemic use. The third level, J01C, identifies it as a beta-lactam antibacterial, specifically a penicillin. The fourth level, J01CA, narrows it down further to penicillins with an extended spectrum. Finally, the fifth level, J01CA04, designates the specific chemical substance, which is amoxicillin. Each successive level adds more specificity, moving from broad anatomical classification to the exact chemical entity.
The DDD, or Defined Daily Dose, is the assumed average daily dose of a drug when used for its main purpose in adults. It doesn’t reflect how doctors actually prescribe it, but it gives a standard unit that can be used for comparisons. This method is helpful because it removes confusion caused by differences in drug strengths, doses, and prescription practices. For example, one hospital might prescribe a drug in two large doses per day, while another uses smaller doses more frequently. Without a standard unit like the DDD, these differences would make comparison based on number of packages consumed misleading. By converting all usage into a common measurement, the ATC/DDD system allows us to clearly see trends, compare practices, and make informed decisions about drug use.
Drug consumption in the hospital sector is expressed as DDD per 100 bed days used (BDU), which adjusts for hospital activity and makes it possible to fairly compare drug consumption across different hospitals no matter how busy that hospital is. Hospital activity data, measured as bed days used, are obtained from the Business Intelligence Unit (BIU) within the Health Service Executive (HSE) and serve as the denominator. The consumption data (numerator) is aligned with hospital activity (denominator) thus only consumption from acute inpatient wards are included in the analyses. Acute inpatient means that data on antibiotics dispensed to outpatients, day cases and external facilities are excluded. Theatres and emergency departments may include both inpatient and outpatient use. Despite the mixed patient demographics in these wards, including consumption data from theatres could be important to account for surgical prophylaxis use, while incorporating emergency department data may provide better overall coverage and is a significant part of the patient’s journey through the hospital.
WHO AWaRe Categories
WHO classifies antibiotics into three categories—Access, Watch, and Reserve—collectively known as the AWaRe classification. Access antibiotics: These antibiotics have a narrow spectrum of activity, meaning they target fewer types of bacteria. They generally cause fewer side effects, have a lower risk of contributing to antimicrobial resistance, and are more cost-effective. Access antibiotics are recommended for treating common infections and should be widely available. Watch antibiotics: These antibiotics have a higher potential to promote antimicrobial resistance. They are typically used in hospitals for treating more severe infections and should be carefully monitored to prevent overuse. Reserve antibiotics: These are last-resort antibiotics, used only under the guidance of an infection specialist. Their use must be tightly controlled to maintain their effectiveness.
For this analysis, the latest (2023) WHO classification of antibiotics has been applied.
AMRIC Categories
This report also compares antimicrobial consumption using a new National AMRIC Green, Amber, and Red antimicrobial categorisation for acute hospitals. This categorisation, developed by the HSE AMRIC team, is adapted from the WHO AWaRe framework. It is designed to enable more effective local and national data analysis, as well as support quality improvement initiatives.
Interpretation of Boxplots
The box represents the the interquartile range (IQR), meaning the bottom and top of the box represents 25th and 75th percentile (the lower and upper quartiles, respectively). The band near the middle of the box is the 50th percentile, the median. The ends of the whiskers represent the lowest data point still within 1.5 times the IQR of the lower quartile, and the highest data point still within 1.5 times the IQR of the upper quartile. Any data point not included between the whiskers is plotted as an outlier with a dot.
Box plots are used to display differences between categories (in this case hospitals) without making any assumptions of the underlying statistical distribution. They help to indicate the degree of dispersion (spread) and skewness in the data, and identify outliers.
Results
J01 Antibacterials for Systemic Use Consumption
Table 1: J01 Antimicrobial Consumption in the Last 5 Years
2020 | 2021 | 2022 | 2023 | 2024 | |
|---|---|---|---|---|---|
National Consumption (Weighted Mean) | 73.5 | 71.9 | 73.1 | 77.7 | 78.4 |
Table 2: J01 Antimicrobial Consumption in the Last 5 Years by ATC-3 Groups
ATC-3 Name | 2020 | 2021 | 2022 | 2023 | 2024 |
|---|---|---|---|---|---|
J01A Tetracyclines | 2.3 | 2.4 | 2.3 | 2.8 | 3.2 |
J01B Amphenicols | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 |
J01C Beta-Lactam Antibacterials, Penicillins | 35.6 | 35.1 | 36.2 | 37.9 | 38.0 |
J01D Other Beta-Lactam Antibacterials | 9.8 | 10.3 | 10.2 | 11.9 | 12.1 |
J01E Sulfonamides and Trimethoprim | 2.6 | 3.0 | 3.2 | 2.7 | 2.6 |
J01F Macrolides, Lincosamides, and Streptogramins | 8.6 | 7.2 | 7.7 | 8.2 | 8.7 |
J01G Aminoglycoside Antibacterials | 3.1 | 2.9 | 2.8 | 3.0 | 2.8 |
J01M Quinolone Antibacterials | 2.9 | 2.6 | 2.5 | 2.5 | 2.3 |
J01X Other Antibacterials | 8.7 | 8.5 | 8.1 | 8.7 | 8.8 |
Total | 73.5 | 71.9 | 73.1 | 77.7 | 78.4 |
Table 3: J01C Beta-Lactam Antibacterials, Penicillins Consumption in the Last 5 Years by ATC-4 Groups
ATC-4 Name | 2020 | 2021 | 2022 | 2023 | 2024 |
|---|---|---|---|---|---|
J01CA Penicillins with extended spectrum | 2.0 | 1.9 | 2.1 | 2.5 | 2.6 |
J01CE Beta-lactamase sensitive penicillins | 2.7 | 2.2 | 2.1 | 2.4 | 1.6 |
J01CF Beta-lactamase resistant penicillins | 8.4 | 8.4 | 8.1 | 8.7 | 8.8 |
J01CR Combinations of penicillins, incl. beta-lactamase inhibitors | 22.5 | 22.5 | 23.9 | 24.4 | 24.9 |
Total | 35.6 | 35.1 | 36.2 | 37.9 | 38.0 |
Table 4: J01D Other Beta-Lactam Antibacterials Consumption in the Last 5 Years by ATC-4 Groups
ATC-4 Name | 2020 | 2021 | 2022 | 2023 | 2024 |
|---|---|---|---|---|---|
J01DB First-generation cephalosporins | 0.6 | 0.7 | 0.8 | 0.9 | 1.0 |
J01DC Second-generation cephalosporins | 3.0 | 3.1 | 3.1 | 3.6 | 3.4 |
J01DD Third-generation cephalosporins | 3.3 | 3.4 | 3.5 | 4.0 | 4.3 |
J01DF Monobactams | 0.5 | 0.6 | 0.6 | 0.8 | 0.8 |
J01DH Carbapenems | 2.3 | 2.5 | 2.3 | 2.5 | 2.5 |
J01DI Other cephalosporins and penems | 0.1 | 0.0 | 0.0 | 0.1 | 0.1 |
J01DE Fourth-generation cephalosporins | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 |
Total | 9.8 | 10.3 | 10.2 | 11.9 | 12.1 |
J02 Antifungals for Systemic Use Consumption
Table 5: J02 Antimicrobial Consumption in the Last 5 Years
2020 | 2021 | 2022 | 2023 | 2024 | |
|---|---|---|---|---|---|
National Consumption (Weighted Mean) | 3.5 | 4.9 | 4.1 | 3.8 | 2.6 |
Consumption by Route of Administration
Table 6: Route of Administration Proportions In the Last 5 Years
Route of Administration (%) | 2020 | 2021 | 2022 | 2023 | 2024 |
|---|---|---|---|---|---|
Inhalation | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 |
Oral | 37.4 | 34.5 | 37.0 | 36.4 | 41.0 |
Parenteral | 62.6 | 65.5 | 63.0 | 63.6 | 59.0 |
Rectal | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 |
Total | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
Consumption by WHO Aware Classification
Table 7: Consumption by WHO AWaRe Classification
WHO AWaRe Categories (%) | 2020 | 2021 | 2022 | 2023 | 2024 |
|---|---|---|---|---|---|
Access | 53.7 | 54.1 | 54.3 | 53.9 | 52.4 |
Not Classified | 0.0 | 0.0 | 0.0 | 0.1 | 0.2 |
Reserve | 3.3 | 3.5 | 3.5 | 3.9 | 3.9 |
Watch | 43.0 | 42.4 | 42.2 | 42.1 | 43.5 |
Total | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
Consumption by AMRIC Categories
Table 8: Consumption by AMRIC Categories
AMRIC Categories (%) | 2020 | 2021 | 2022 | 2023 | 2024 |
|---|---|---|---|---|---|
Amber | 64.5 | 63.6 | 64.6 | 64.1 | 64.6 |
Green | 29.5 | 30.0 | 29.3 | 29.5 | 29.1 |
Not Classified | 0.2 | 0.2 | 0.2 | 0.2 | 0.3 |
Red | 5.8 | 6.2 | 5.9 | 6.1 | 6.0 |
Total | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
