Release date: 17 April 2024
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 3.2.1 of both Action Plans suggested collecting the antimicrobial dispensing data from Hospital Authority (HA) to monitor antimicrobial usage in public hospitals and clinics. After studying the antimicrobial dispensing data of public hospitals and clinics of HA (including both non-inpatient and inpatient services), AMU surveillance reports were compiled and published on the Centre for Health Protection website. This is the sixth report which provides a brief account of the surveillance findings for the year 2022. Further details are enclosed in the PowerPoint file for reference.
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 2021) 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 |
Dispensing data for a total of 15 broad-spectrum antimicrobials identified by experts in HA (also known as ‘Big Guns’) were examined because of their importance in treating resistant infections.
The surveillance period for AMU is defined by calendar year. Results were analysed and presented as Defined Daily Dose (DDD)[3]. The 2022 version of WHO ATC DDD constants was adopted in this report. As there has been no change in DDD constants for those antimicrobials dispensed in HA captured by this surveillance system, the DDD constants adopted for calculation for previous years remained the same as in the last report of 2021.
Since the first Action Plan, i.e. Action Plan 2017-2022, was published in July 2017, the situation of 2016 has been chosen as the baseline for comparison.
Following the practice of the European Centre for Disease Prevention and Control (ECDC)[4], compound annual growth rate (CAGR) was adopted to illustrate the average annual rate of change when comparing antimicrobials dispensed in 2022 with that in 2016.
CAGR = (SU 2022 / SU 2016 ) (1/6) - 1
In this equation, SU2022 and SU2016 refer to the total amount of antimicrobials dispensed for year 2022 and 2016, respectively.
Total antimicrobials dispensed in public hospitals and clinics
For inpatient services of HA, the total antimicrobial dispensing volume continued to decrease in 2022 was about 839.61 DDD/1,000 patient days. On the other hand, for non-inpatient services, the total antimicrobial dispensed remained stable in 2021 and 2022, which were 271.90 and 272.11 DDD/1,000 attendances respectively.
Meanwhile, the service volume of various HA services in 2022 has rebounded to a level similar to the pre-COVID era, in which the total service volume in 2022 for non-inpatient services and inpatient services was 14,553,000 attendances and 7,067,000 patient days, respectively.
Ten Most Dispensed Antimicrobials in Public Hospitals and Clinics
The ten most dispensed antimicrobials (in DDD) accounted for around 80% of all antimicrobials dispensed for HA services in 2022. Amoxicillin/ clavulanate (Augmentin) maintained as the most dispensed antimicrobial in 2022, accounting for around 41.41% of all antimicrobials dispensed in HA of the year. Notably, meropenem (CAGR (16-22): 14.0%) and ceftriaxone (CAGR (16-22): 4.89%) emerged as two of the ten most dispensed antimicrobials in 2022, replacing cloxacillin and nitrofurantoin from the previous year. Furthermore, compared to 2021, four of the ten most dispensed antimicrobials experienced a continuous increase in dispensing volume, specifically piperacillin/tazobactam (CAGR (21-22):7.08%), co-trimoxazole (CAGR (21-22): 3.45%), meropenem (CAGR (21-22): 8.88%), and ceftriaxone (CAGR (21-22): 13.1%). In contrast, doxycycline dispensing volume showed a reduction for the first time in 2022 (CAGR (21-22): -6.04%) since 2016, the year chosen as baseline for comparison.
Antimicrobials dispensed in HA by service
Non-inpatient Services and by service
In 2022, the number of attendances in Primary Care (GOPC) decreased from 6.3 million in 2021 to 5.2 million. Concurrently, the amount of dispensed antimicrobial dropped from 196.3 to 164.0 DDD per 1,000 attendances. In contrast, for Specialist Out-patient (Clinical) services, attendances decreased from 8.2 million in 2021 to 7.7 million in 2022. However, the amount of dispensed antimicrobials increased from 276.5 in 2021 to 290.6 DDD per 1,000 attendances in 2022.
Among the ten most dispensed antimicrobials in non-inpatient services, amoxicillin/ clavulanate (Augmentin) remained as the most dispensed antimicrobial in 2022 with a decrease in dispensing volume since 2019 (CAGR (16-22): -1.12%). Even though the number of attendees decreased in 2022 compared to 2021, five of the ten most dispensed antimicrobials in non-inpatient services continued to increase in dispensing volume, including doxycycline (CAGR (16-22): 11.5%), co-trimoxazole (CAGR (16-22): 9.80%), levofloxacin (CAGR (16-22): -1.12%), azithromycin (CAGR (16-22): 7.26%), and rifaximin (CAGR (16-22): 27.1%). Notably, while a reduction in doxycycline dispensing volume was observed in inpatient service, the dispensing volume in non-inpatient services continued to increase.
Inpatient Services and by specialty
In 2022, while patient-days in medicine returned to pre-COVID levels, the amount of antimicrobials dispensed in DDD per 1,000 patient-days continued to decline (CAGR (21-22): -4.28%). Similarly, in ICU/HDU, patient-days in 2022 (73,000 patient-days) surpassed the 2019 level (71,000 patient-days), yet the amount of antimicrobials dispensed remained lower than 2019 (CAGR (19-22): -2.20%). In contrast, for surgery and O&T, the number of patient-days in 2022 remained lower than that of 2019, but after adjusting for patient-days, the amount of antimicrobials dispensed in these two departments was still higher than in 2019 (CAGR (19-22): 2.15% and 1.55% respectively).
Regarding the ten most dispensed antimicrobials in inpatient services in 2022, Amoxicillin/ clavulanate (Augmentin) continued to be the most dispensed antimicrobial (366.49 DDD/1,000 patient days). Among the ten most dispensed antimicrobials in inpatient services, three are broad-spectrum antimicrobials: piperacillin/tazobactam (66.36 DDD/1,000 patient days), meropenem (32.83 DDD/1,000 patient days), and vancomycin (19.24 DDD/1,000 patient days). All three of these antimicrobials experienced an increase in dispensing volume compared to 2021 figures. Furthermore, piperacillin/tazobactam surpassed doxycycline in 2022, becoming the second most commonly dispensed antimicrobial in inpatient services.
Broad-spectrum Antimicrobials Dispensed in Inpatient Services
Regarding the broad-spectrum antimicrobials, their dispensing quantities account (in DDD) for about 9.17% of total antimicrobials dispensed in HA in 2022.
The three most dispensed broad-spectrum antimicrobials in 2022 continued to be piperacillin/ tazobactam, meropenem and vancomycin (66.33, 32.84, and 19.26 DDD/1,000 patient days, respectively). The dispensing volume of these three broad-spectrum antimicrobials increased in 2022 compared to 2021. In contrast, the dispensing volume of ertapenem, another broad-spectrum antimicrobial, showed a decrease for the first time (CAGR (21-22): -2.44%).
In 2022, ‘ICU/ HDU’ continued to be the specialty of inpatient services of HA with the largest quantity of broad-spectrum antimicrobials dispensed (514.44 DDD per 1,000 patient days), followed by ‘Medicine’, ‘Surgery’, ‘O&T’ and ‘Others’ (172.95, 158.68, 100.94 and 76.82 DDD/ 1,000 patient days respectively). Antimicrobial dispensing in ICU/HDU peaked in 2020 and plateaued in both 2021 and 2022 (CAGR (20-22): -3.28%). In contrast, the dispensing volume of antimicrobials in medicine, surgery, O&T, and other specialties continued to show an increase (CAGR (21-22): 7.49%, 8.48%, 6.15% and 0.33% respectively).
The key findings in 2022 surveillance (the third year since the COVID-19 pandemic) included:
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Continuous monitoring of the antimicrobial usage in HA hospitals/ clinics to assess the effectiveness of the Antibiotics Stewardship Programme (ASP), with a focus on the increased dispensing of broad-spectrum antimicrobials in inpatient services.
Investigation on the discrepant trend of doxycycline dispensing in inpatient and non-inpatient settings, as the overall reduction in HA contrasts with the continued increase in non-inpatient services.
With HA services still affected by COVID-19 in 2022, it is reasonable to anticipate an increase in antimicrobial use in 2023 as the city returns to normalcy. Close monitoring of antimicrobial usage is warranted to inform future stewardship efforts..
We would like to acknowledge stakeholders from HA including the Information Technology & Health Informatics Division, Quality and Safety Division, Strategy and Planning Division, Chief Pharmacist’s Office, and various Working Groups for provision of input to facilitate compilation of the AMU surveillance findings for year 2022.
[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] DDD is a standardised unit adopted by WHO to facilitate the comparison of drug usage.
[4] https://www.ecdc.europa.eu/sites/default/files/documents/Antimicrobial-consumption-in-the-EU-Annual-Epidemiological-Report-2019.pdf (same method was also adopted in year 2021 report)