What is the most appropriate metric for the assessment of volume of antibiotic use?

One of the core elements of antibiotic stewardship is surveillance and monitoring of quantity of antibiotic use. This requires tools for measuring the quantity of antibiotic use. However, these metrics have not been standardized, and different metrics are used across different countries, regions and individual healthcare settings. In the literature, there is much controversy on the most appropriate metric for monitoring antibiotic use. Several authors have questioned the relevance of DDDs, which are recommended by the WHO, while others still prefer using DDDs as the best available metric. The results of the recent DRIVE-AB project suggest that a combination of metrics may be the best approach, since all metrics have limitations and provide different perspectives.

Antimicrobial prescribing by Belgian dentists in ambulatory care, from 2010 to 2016

OBJECTIVES

To describe antimicrobial prescribing by Belgian dentists in ambulatory care, from 2010 until 2016.

MATERIALS AND METHODS

Reimbursement data from the Belgian National Institute for Health and Disability Insurance were analysed to evaluate antimicrobial prescribing (WHO ATC-codes J01/P01AB). Utilisation was expressed in defined daily doses (DDDs), and in DDDs and packages per 1000 inhabitants per day (DID and PID, respectively). Additionally, the number of DDD and packages per prescriber was calculated.

RESULTS

In 2016, the dentistry-related prescribing rate of 'Antibacterials for systemic use' (J01) and 'Antiprotozoals' (P01AB) was 1.607 and 0.014 DID, respectively. From 2010 to 2016, the DID rate of J01 increased by 6.3%, while the PID rate declined by 6.7%. Amoxicillin and amoxicillin with an enzyme inhibitor were the most often prescribed products, followed by clindamycin, clarithromycin, doxycycline, azithromycin and metronidazole. The proportion of amoxicillin relative to amoxicillin with an enzyme inhibitor was low. The narrow-spectrum antibiotic penicillin V was almost never prescribed.

CONCLUSIONS

Antibiotics typically classified as broad- or extended-spectrum were prescribed most often by Belgian dentists during the period 2000-2016. Although the DID rate of all 'Antibacterials for systemic use' (J01) increased over the years, the number of prescriptions per dentist decreased since 2013. The high prescription level of amoxicillin with an enzyme inhibitor is particularly worrying. It indicates that there is a need for comprehensive clinical practice guidelines for Belgian dentists.

Comparing antibiotic consumption between two European countries: are packages an adequate surrogate for prescriptions?

Defined daily doses (DDD) are the gold standard indicator for quantifying prescriptions. Since 2014, the European Centre for Disease Prevention and Control (ECDC) has also been using the number of packages per 1,000 inhabitants per day (ipd), as a surrogate for prescriptions, to report antibiotic consumption in the community and to perform comparisons between European Union (EU) countries participating in the European Surveillance of Antimicrobial Consumption Network (ESAC-Net). In 2015, consumption was reported to range across Europe from 1.0 to 4.7 packages per 1,000 ipd. Our analysis showed that consumption of antibiotics for systemic use per 1,000 ipd was on average 1.3 times greater in France than in Belgium when considering prescriptions in the numerator, 2.5 times greater when considering packages and 1.2 times greater when considering DDD. As long as the same metrics are used over time, antibiotic consumption data aggregated and disseminated by ECDC are useful for assessing temporal trends at the European level and within individual countries; these data may also be used for benchmarking across EU countries. While DDD - although imperfect - are the most widely accepted metric for this purpose, antibiotic packages do not appear suitable for comparisons between countries and may be misleading.