Release date: 11 April 2023
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. The first Hong Kong Strategy and Action Plan on Antimicrobial Resistance (2017- 2022) was launched in July 2017, and the second action plan (2023-2027) in November 2022.
The Action Plans set out monitoring antimicrobial usage as one of the strategic actions. Activity 3.1.2 of both Action Plans suggested collecting the antimicrobial supply data from different sectors as a 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 on the Centre for Health Protection website annually. This is the sixth report which provides a brief account of the findings from 2016 to 2021. Please click here to view further details.
Scope of data
A total of eight sectors, namely the 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 the WHO on surveillance of antimicrobial consumption (AMC)[1], the following core set of antimicrobials under WHO’s Anatomical Therapeutic Chemical (ATC) classification system was adopted for surveillance purposes (Version 2022 was adopted for calculations). Antimicrobials 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 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 figures for a total of 15 selected broad-spectrum antimicrobials (also known as ‘Big Guns’) were examined separately in this surveillance exercise for their importance in the treatment of resistant bacterial infections. The same is being monitored in AMU surveillance with HA Dispensing Data.
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 mentioned above, version 2022 of the DDD values were adopted for calculations in this report. Since some DDD values were updated by WHO in recent years[5], the DDD figures of previous years have been re-calculated, which would be different from the statistics in the past reports.
Statistical method
Since the first Action Plan, i.e. Action Plan 2017- 2022, 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) practice, the compound annual growth rate (CAGR) was adopted to illustrate the average annual rate of change when comparing antimicrobials supplied in 2021 with that in 2016.
CAGR = (SU2021 / SU2016)(1/5) - 1
In the above equation, SU2021 and SU2016 refer to the total amount of antimicrobials supplied in 2021 and 2016, respectively.
Overall Antimicrobials Wholesale Supply (2016 – 2021)
The overall antimicrobials supply[6] decreased from 20.37 DID in 2016 to 18.41 DID in 2017 but gradually increased to 18.96 DID in 2019. However, it significantly reduced to 13.62 DID in 2020 and 13.74 DID in 2021 (with a mild increase of 0.12 DID ( ↑0.9%) from 2020 to 2021) during the COVID-19 pandemic. (↓5.22 DID or ↓27.6% when compared the DID of 2021 with that of 2019, CAGR(2016-2021): -7.6%).
Distribution by WHO AWaRe Categorisation
Antimicrobials fell under Access constituted 55.8% of all antimicrobials supplied in 2016. However, the proportion gradually increased to 64.3% in 2021, exceeding the 60% benchmark recommended by WHO. On the other hand, Watch antimicrobials decreased steadily from 40.3% to 31.6% (2016-2021), while Reserve antimicrobials only constituted 0.07-0.19% of the total supply from 2016 to 2021. Antimicrobials not categorised under the above three categories were grouped as ‘Others’ and constituted about 3.4 to 3.9% of all antimicrobial supply.
From 2016 to 2021, the supply of Access and Watch antimicrobials in DDD decreased by -4.9% and -11.9% in CAGR, respectively, while Reserve antimicrobials increased by 11.6% in CAGR. However, readers should interpret the results with caution as the total number of antimicrobials under Reserve supplied in Hong Kong increased from five in 2016 to ten in 2021.
Distribution by Sector
In 2021, around half (49.3%) of antimicrobials supply went to private doctors, followed by HA (30.7%) and private hospitals (6.3%). The percentage of antimicrobials supplied to community pharmacies decreased gradually from 18.5% in 2016 to 5.6% in 2021, with the CAGR of -27.2%.
After the significant drop from 2019 to 2020 in the antimicrobials supplied to private doctors (10.91 to 6.81 DID, ↓37.6% ), private hospitals (1.31 to 0.93 DID, ↓28.6%) and community pharmacies (1.46 to 1.05 DID, ↓27.7%), a mild decrease, from 2020 to 2021, was shown in private hospitals and community pharmacies, while a mild increase was seen in private doctors (6.81 to 6.90 DID, ↑1.4%). In addition, from 2020 to 2021, a mild increase was observed with Hospital Authority (HA) (4.01 to 4.29 DID, ↑7.0%), whereas a mild decrease was observed with Department of Health (DH) (0.19 to 0.17 DID, ↓11.9%).
From 2016 to 2021, the supply to dentists showed an increase of CAGR 13.6% though the absolute amount was small (0.38 DID in 2016 to 0.72 DID in 2021), while the supply to community pharmacies showed the most apparent decrease of CAGR 27.2%. In addition, from 2016 to 2021, an increase in supply was shown in HA (CAGR: 1.1%), whereas supplies to private doctors, private hospitals and DH were decreasing (CAGR: -8.6%, -4.3% and -2.3%, respectively).
Distribution by ATC Pharmacological Subgroup
In 2021, beta-lactam antibacterial, penicillins (J01C) was the most commonly supplied antimicrobial group (46.0%) by wholesale, followed by tetracyclines (J01A) (14.6%), macrolides, lincosamides and streptogramins (J01F) (10.9%), quinolone antibacterials (J01M) (10.4%), and other beta-lactam antibacterials (J01D) (9.0%). Tetracyclines (J01A) has overtaken macrolides, lincosamides and streptogramins (J01F) to become the second most commonly supplied antimicrobial group since 2020.
From 2016 to 2021, nitroimidazole derivatives, agents against amoebiasis and other protozoal diseases (P01AB), showed the most increase with the CAGR of 2.8%, followed by other antibacterials (J01X) with the CAGR of 1.3%. Except for these two groups, the CAGR of every other group was negative from 2016 to 2021 in terms of DID. Other beta-lactam antibacterials (J01D), and macrolides, lincosamides and streptogramins (J01F) had the most significant reduction in CAGR of -15.3% and -14.8%, respectively.
Ten Most Commonly Supplied Antimicrobials
From 2016 to 2021, the ten most commonly supplied antimicrobials contributed to more than 80% of all antimicrobials supplied in the corresponding year. In 2021, amoxicillin and beta-lactamase inhibitor (J01CR02) continued to be the most commonly supplied antimicrobial, accounting for 26.3% of all antimicrobials by wholesale, followed by amoxicillin (J01CA04) (13.0%) and doxycycline (J01AA02) (12.6%).
Except for metronidazole (J01XD01/P01AB01) and doxycycline (J01AA02) with positive CAGR of 2.2% and 0.5%, respectively, the CAGR from 2016 to 2021 of the other top ten most supplied antimicrobials were negative. The wholesale supply of azithromycin (J01FA10) and cefuroxime (J01DC02) decreased the most (CAGR: ↓18.2% and ↓17.0% respectively) from 2016 to 2021.
Wholesale Supply of Selected Broad-spectrum Antimicrobials (‘Big Guns’)
Most of these broad-spectrum antimicrobials (about 99%) were supplied to HA and private hospitals from 2016 to 2021. In 2021, piperacillin/tazobactam continued to be the most commonly supplied (42.1%) broad-spectrum antimicrobial, followed by meropenem (21.8%) and vancomycin (14.2%). These three most commonly supplied broad-spectrum antimicrobials from 2016 to 2021 accounted for about 78% of all broad-spectrum antimicrobials under monitoring in 2021.
The wholesale supply of these selected broad-spectrum antimicrobials increased by an average annual increase of 0.025 DID (or 8.3% in CAGR) from 2016 to 2021. In contrast, the overall CAGR of all antimicrobials supplied reduced by 7.6%.
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[7] values in 2019 by WHO resulted in re-calculating of the past data; hence the figures in this presentation would be different from the statistics 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 which may cause the supply of a particular antimicrobial to increase by a substantial margin compared with last year.
Readers are cautioned not to use the Hong Kong figures to make a 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.
The key findings of the 2021 surveillance include the following:
Readers should interpret the 2021 results with caution as the pandemic of Covid-19 might have changed the regular practice and arrangement of medical services in Hong Kong. Close monitoring of the antimicrobial supply data is required in subsequent years to further assess its impact of COVID-19.
As most antimicrobials were supplied to private doctors (49.3%) and HA (30.7%), strengthening the implementation of the Antibiotic Stewardship Programme in primary care and public hospitals is recommended.
Most broad spectrum antimicrobials (‘Big Guns’) were supplied to HA and private hospitals. The continuous rising trend of these broad spectrum antimicrobials warrants to further exploration and enhance the Antibiotic Stewardship Programme in hospitals.
We would like to acknowledge product registration certificate holders and licensed drug wholesalers for providing wholesale supply data for 2021 and the Drug Office of DH for facilitating the surveillance exercise.
Please click here to view the Past Reports.
[1] https://www.who.int/publications/i/item/9789240012639
[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 emphasise the importance of their optimal uses and potential for antimicrobial resistance. WHO encourages countries or regions to work towards having 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. https://www.who.int/publications/i/item/2021-aware-classification
[4] DDD is a standardised unit adopted by WHO to facilitate the comparison of drug usage.
[5] For example, the DDD constant for oral use of amoxicillin was changed from 1000mg in 2018 to 1500mg in 2019
[6] Non-human use antimicrobials supplied to veterinary surgeons and farmers were excluded.
[7] WHO ATC 2022 version was adopted for DDD calculation