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Antimicrobial Usage (AMU) Surveillance in Hong Kong - Wholesale Supply Data (2019)

Release date: 21 May 2021

Background

The HKSAR Government attaches great importance to the threat of antimicrobial resistance (AMR). A High Level Steering Committee (HLSC) chaired by the Secretary for Food and Health has been established to formulate strategies and implement actions to combat AMR in Hong Kong, and the Hong Kong Strategy and Action Plan on Antimicrobial Resistance (2017- 2022) (Action Plan) was launched in July 2017.

The Action Plan sets out monitoring of antimicrobial usage as one of the strategic actions. Activity 3.1.2 of the Action Plan further suggested to collect the antimicrobial supply data from different sectors as proxy to reflect the overall usage and trend of antimicrobial usage. The collection of the wholesale supply data of antimicrobials through respective product registration certificate holders and licensed drug wholesalers has been regularised as an ongoing annual surveillance exercise and reports were compiled and published at Centre for Health Protection website annually. This is the fourth report which provides a brief account of the findings for year 2016 to 2019. Please click here to view further details.


Methodology

Scope of data

A total of eight sectors, namely Department of Health (DH), Hospital Authority (HA), private hospitals, private doctors (mutually exclusive with private hospitals), dentists, veterinary surgeons, community pharmacies and farmers (who had the Antibiotics Permits issued by the Director of Agriculture, Fisheries and Conservation Department), were included in the surveillance.


Antimicrobials Monitored

Following the recommendation of WHO for AMU surveillance[1], the following core set of antimicrobials under WHO’s Anatomical Therapeutic Chemical (ATC) classification system (Year 2019) was adopted for surveillance purpose. Only antimicrobials given for systemic use[2] were included while topical antimicrobials were excluded.

ATC Code ATC Group/Subgroup
J01 Antibacterials for systemic use
P01AB Nitroimidazole derivatives, agents against amoebiasis and other protozoal diseases
A07AA Antibiotics, intestinal antiinfectives


WHO AWaRe Categorisation

Wholesale supply data of antimicrobials was also grouped into three different categories: Access, Watch and Reserve, according to WHO AWaRe categorisation[3] in 2019 and those not listed under WHO AWaRe were grouped as ‘Others’.


Broad-spectrum Antimicrobials (Big Guns)

Wholesale supply for a total of 15 broad-spectrum antimicrobials (also known as ‘Big Guns’) were also examined separately in this surveillance.


Measurement

The surveillance period is defined by calendar year. Results were analysed and presented as Defined Daily Dose (DDD)[4] and DID (DDD per 1,000 inhabitants per day). As some of the DDD constants were updated by WHO in 2019[5], the DDD figures of previous years have been re-calculated accordingly which would be different from the figures presented in the past reports.


Statistical method

Since the Action Plan was published in 2017, the situation of 2016 has been chosen as the baseline for comparison.

Following the European Centre for Disease Prevention and Control (ECDC), compound annual growth rate (CAGR) was adopted to illustrate average annual rate of change when comparing antimicrobials supplied in 2019 with that in 2016.

CAGR = (SU2019 / SU2016)(1/3) - 1

In the above equation, SU2019 and SU2016 refer to the total amount of antimicrobials supplied in 2019 and 2016 respectively.


Results

Overall Antimicrobials Wholesale Supply (2016 – 2019)

The overall antimicrobials supply decreased from 20.24 DID in 2016 to 18.36 DID in 2017 but gradually increased to 18.88 DID in 2019 (CAGR: -2.3%).


Distribution by WHO AWaRe Categorisation

Antimicrobials fell under Access constituted 56.1% of all antimicrobials supplied in 2016. The proportion gradually increased to 59.2% in 2019. Antimicrobials under Watch gradually decreased from 40.5% to 37.4% from 2016 to 2019, while those under Reserve only constituted around 0.1 to 0.2% of the overall supply during 2016 to 2019. Antimicrobials grouped as ‘Others’ constituted about 3.1 to 3.3% of all antimicrobial supply.

In terms of DID, there was decreased supply in antimicrobials under Access and Watch from 2016 to 2019 (CAGR of -0.5% and -4.8% respectively).


Distribution by Sector

In 2019, over half (56.9%) antimicrobials supply went to private doctors, followed by HA (23.4%) and community pharmacies (7.5%).

From 2016 to 2019, the proportion of antimicrobials supplied to community pharmacies decreased gradually from 18.2% in 2016 to 7.5% in 2019 with CAGR -27.4%. The proportion of antimicrobials supplied to dentists showed sharpest increase with CAGR 19.1% from 2016 to 2019 though the absolute amount was small (0.37 DID in 2016 to 0.63 DID in 2019). Increase in supply was also shown in private hospitals (CAGR: 6.3%), HA (CAGR: 3.2%) and private doctors (CAGR: 0.3%), while supply to community pharmacies showed the sharpest decrease from 2016 to 2019 (CAGR: -27.4%), followed by DH (CAGR: -3.1%).


Distribution by ATC Pharmacological Subgroup

In 2019, beta-lactam antibacterial, penicillins (J01C) was the most commonly supplied antimicrobial group (44.4%), followed by macrolides, lincosamides and streptogramins (J01F) (14.9%), quinolone antibacterials (J01M) (11.6%), other beta-lactam antibacterials (J01D) (11.6%), and tetracyclines (J01A) (10.9%). In terms of change in DID from 2016 to 2019, nitroimidazole derivatives (P01AB) and other antibacterials (J01X) increased most (5.8% and 5.0% in CAGR respectively) while amphenicols (J01B) and other beta-lactam antibacterials (J01D) decreased most (-70% and -8.4% in CAGR respectively).


Ten Most Commonly Supplied Antimicrobials

From 2016 to 2019, the ten most commonly supplied antimicrobials contributed to more than 80% of all antimicrobials supplied in the corresponding year. In 2019, amoxicillin and beta-lactamase inhibitor (J01CR02) was the most commonly supplied antimicrobial, accounted for 26.0% of all antimicrobials by wholesale, followed by amoxicillin (J01CA04) (12.7%) and doxycycline (J01AA02) (9.4%).

The supply of amoxicillin and beta-lactamase inhibitor (J01CR02) and metronidazole (J01XD01/P01AB01) increased most (CAGR: 5.6% and 5.1% respectively), while the supply of cefuroxime (J01DC02) and combination of penicillins (J01CR50) decreased most (CAGR: -8.0% and -7.5% respectively) from 2016 to 2019.


Wholesale Supply of Selected Broad-spectrum Antimicrobials

Majority of these broad-spectrum antimicrobials (about 99%) were supplied to HA and private hospitals from 2016 to 2019. In 2019, piperacillin/tazobactam was the most commonly supplied (43.6%) broad-spectrum antimicrobial, followed by meropenem (20.2%) and vancomycin (12.8%). They had been the three most commonly supplied broad-spectrum antimicrobials from 2016 to 2019 accounted for about 76% of all broad-spectrum antimicrobials under monitoring in 2019.

The total wholesale supply of selected broad-spectrum antimicrobials increased by 9.0% in CAGR from 2016 to 2019.


Remarks on interpretation of results

Defined Daily Dose (DDD) is a technical unit of use that does not necessarily reflect the recommended or average prescribed dose, while there are no separate DDDs for children which makes the DDD estimates for paediatric formulations more difficult to interpret.

Change in DDD[6] constants in 2019 by WHO resulted in re-calculating of the past data and hence the figures in this presentation would be different from the figures presented in the past.

The surveillance of antimicrobials by wholesale supply in Hong Kong is a voluntary self-reporting by licensed drug wholesalers and could have reporting errors.

Wholesale supply data is used as a proxy for the amount of antimicrobials supplied to each sector, therefore the figures are not equivalent to dispensing figures and could be affected by marketing strategies, e.g. discount offers may cause the supply of a particular antimicrobial to increase by a substantial margin when compared with that of last year.

Readers are cautioned not to use the Hong Kong figures to make direct comparison with that of other countries as the health care services provision system and the methodology in collecting the surveillance data may not be the same, e.g. some countries may use dispensing or prescription data as their AMU surveillance data source instead of wholesale supply data and they are different in nature.


Summary

The key findings of 2019 surveillance include:

  • Overall wholesale supply of antimicrobials decreased from 20.24 DID in 2016 to 18.36 DID in 2017 but gradually increased to 18.88 DID in 2019 and the compound annual growth rate from 2016 and 2019 was -2.3%
  • Hong Kong reached 59.2% of overall antimicrobial supplied under the Access group of WHO AWaRe categorisation in 2019, which is very close to the benchmark of 60% as recommended by WHO
  • Majority of antimicrobials supplied in Hong Kong went to private doctors (56.9% in 2019), the major primary healthcare service providers, followed by Hospital Authority (23.4%) and community pharmacies (7.5%)
  • Percentage of antimicrobials supplied to community pharmacies showed gradual reduction from 18.2% in 2016 to 7.5% in 2019
  • Overall wholesale supply of broad-spectrum antimicrobials in Hong Kong showed an increase of 9.0% (CAGR) from 2016 to 2019


Recommendations

Though the wholesale supply in DID in 2019 was lower than that of 2016, gradual increase in DID is observed from 2017 to 2019 would warrant monitoring.

Apart from sharing the surveillance results, we would continue to strengthen communication with stakeholders of respective sectors to solicit their support on enhancing the implementation of antibiotic stewardship programme

As the majority of antimicrobials were supplied to private doctors (56.9%) and HA (23.4%), strengthening the implementation of antibiotic stewardship programme in primary care and public hospitals are recommended

Majority of the broad spectrum antimicrobials were supplied to HA and private hospitals. The continuous rising trend of these broad spectrum antimicrobials warrants to further explore and enhance the antibiotic stewardship programme in hospitals.


Acknowledgement

We would like to acknowledge product registration certificate holders and licensed drug wholesalers for provision of wholesale supply data for year 2019, and the Drug Office of DH for facilitating the surveillance exercise.


[1] https://apps.who.int/iris/rest/bitstreams/1313107/retrieve

[2] Only antimicrobials given by oral, parenteral, rectal and inhalation were included in the surveillance

[3]  AWaRe classifies antimicrobials into the above-mentioned three stewardship groups to emphasize the importance of their optimal uses and potential for antimicrobial resistance. WHO encourages countries or regions to work towards to have 60% or more of the overall antimicrobials supplied under Access and reduce the usage of antimicrobials under Watch and Reserve for their higher potential to cause antimicrobial resistance.

[4] DDD is a standardised unit adopted by WHO to facilitate comparison of drug usage.

[5] For example, DDD constant for oral use of amoxicillin was changed from 1000mg in 2018 to 1500mg in 2019

[6] WHO ATC 2019 version was adopted for DDD calculation