Community use of antibiotics single map Consumer summary (108 kb, PDF)

Background

Antimicrobial resistance is emerging as a problem worldwide. Overuse of antibiotics is one of the causes of antimicrobial resistance. In New Zealand, up to 95 percent of antibiotics are dispensed in the community[1], suggesting that a focus on promoting appropriate community use is an important way to address antimicrobial resistance. Recent analysis indicates there is likely to be a mix of underuse and overuse of antibacterials relative to health need, particularly in Māori and Pacific peoples. This suggests the balance of under- and over-prescribing of antibiotics in New Zealand needs to be better understood[2].

The purpose of this Atlas domain is to highlight regional and demographic variation in community antibiotic use, with the goal of prompting debate and raising questions about why differences exist. Professor John Wennberg defined unwarranted variation as being variation that cannot be explained by differences in either patient need or patient preference. This Atlas invites readers to ask questions to understand how much antibiotic prescribing can be attributed to patient need and how much might reflect unwarranted variation[3].

This Atlas uses data from the Pharmaceutical Collection and there are limitations readers should be aware of. Firstly, the reason the antibiotic was prescribed is not known, therefore no judgement on the appropriateness or otherwise can be drawn.

Furthermore, this collection does not capture:

  • antibiotics that were prescribed but not dispensed
  • antibiotics that were provided over-the-counter, such as trimethoprim (prescribed trimethoprim is included)
  • antibiotics dispensed on a practitioner supply order (PSO).

PSO is used where an individual prescription may not be possible, for example, in the school-based rheumatic fever prevention programme. On average, PSO represents around 4 percent of antibiotics dispensed, but the use of PSO ranges between district health boards (DHBs) from 0.9 to 19 percent.

Key observations

  • Of people who visited their GP in 2017, around half were dispensed at least one systemic antibiotic. The prescription could have come from any prescriber.
  • Antibiotic use was highest in the youngest and oldest:
    • Of 0–4-year-olds, 65 percent were dispensed an antibiotic in 2017
    • Of those aged 85 and over living in aged residential care (ARC), 70 percent received an antibiotic in 2017.
  • Topical antibiotic use has reduced over the last three years, from 6 percent to 4 percent. This varied 3.8-fold between DHBs.
  • Some antibiotics are prescribed 37 percent more in winter than in summer. Increased prescribing in winter may indicate that antibiotics are being prescribed for individuals with colds and flus, and therefore may represent an opportunity to reduce antibiotic use.
  • Eighty-three percent of penicillins dispensed are broad-spectrum.
  • The dispensing of antibiotics specifically indicated for urinary tract infections (UTIs) increased sharply with age and for people living in ARC.
  • On average, 32 and 33 percent of people were dispensed an antibiotic within 30 days of a medical and surgical admission, respectively.
Of people who visited their GP in a year, half were dispensed at least one systemic antibiotic.
  • The highest rate of antibiotic dispensing was in 0–4-year-olds, with 65 percent dispensed in 2017, followed by 58 percent of 5–9-year-olds. Antibiotic use increased again with older age.
  • DHB variation was 1.4-fold, with wider variation between DHBs in ethnic rates.
  • Pacific peoples had the highest ethnic rate, particularly in young children, with 81 percent of 0–4-year-olds dispensed an antibiotic in 2017. This has reduced since 2015, where 88 percent of young Pacific children were dispensed an antibiotic.
  • Māori also had a high rate of antibiotic use, predominantly in the 0–14 age groups. It is not known whether this use is appropriate or not.
  • These observations should be interpreted in the context of research showing higher rates of infectious disease in Māori and Pacific peoples[4].
When all dispensings in a year were calculated against all GP visits, the rate of dispensing was lower, at 39 percent. This lower rate reflects that, while around half the people who attended primary care in a year were dispensed an antibiotic, this does not mean that half of GP visits resulted in an antibiotic being dispensed.
  • Over 2017, 1,844,488 people were dispensed a systemic antibiotic in the community and they received a total of 3,794,245 antibiotic dispensings. To provide context, in 2017, antibiotics were dispensed to 185,000 people in the month following hospital admission, most of which were medical admissions (135,635). Overall, the majority of community prescriptions originated from primary care.
  • For a further analysis reporting which antibiotics were dispensed by age group, see the paper by Whyler et al 5].
People living in ARC were dispensed more antibiotics than those living in the community.
  • In those aged 85 and over living in ARC, DHB rates ranged from 55 percent to 83 percent, with an average rate of 70 percent. Three DHBs had statistically significantly higher dispensing rates. This compares with a national average of 57 percent for people 85 and over living in the community.
Topical antibiotic use has decreased statistically significantly since 2015, from 6 percent to 3.9 percent.
  • Use varied 3.8-fold between DHBs.
  • As with systemic antibiotics, rates were higher in young children and in Māori and Pacific populations. However, previous research has shown that the rate of hospital admission for skin and soft tissue infection are highest in Māori and Pacific peoples[6].
  • The reduction in rates may reflect more appropriate use of topical antibiotics.
Key antibiotics were prescribed 37 percent more in winter than in summer.
  • Since 2015, antibiotic dispensing over the winter months has decreased from 39 percent to 37 percent higher than in summer.
  • Seasonal antibiotic use was highest in the young, with 60 percent more antibiotics dispensed in winter in those aged 0–4 years, compared with a 24 percent increase in those aged 75 and over.
  • Increased prescribing in winter may indicate that antibiotics are being prescribed for viral respiratory infections. A study in the United Kingdom found social norm feedback reduced the seasonal increase in antibiotic prescribing over winter[7]. This may represent an opportunity to reduce antibiotic use. BPAC has guidance on managing the cold season without antibiotics[8].
  • Typically, seasonal variation was greater in the North Island DHBs. This may reflect differences in population groups or other factors such as climate.
Of people dispensed a penicillin, 83 percent of people received a broad-spectrum penicillin.
  • This Atlas uses the New Zealand Formulary classification, which defines amoxicillin and amoxicillin with clavulanic acid as broad-spectrum. All other penicillins are narrow-spectrum.
  • As a percent of all penicillin dispensed, amoxicillin and amoxicillin with clavulanic acid was used 83 percent of the time for all age groups. Broad-spectrum penicillin use was highest in those aged 0–4 years at 93 percent; this equated to 138,383 children in 2017. This raises questions such as:
    • which conditions in box 1 are likely to be relevant for 0–4-year-olds
    • are there other factors that may contribute, for example, formulation and palatability?
  • Broad-spectrum antibiotics are associated with antimicrobial resistance and are generally recommended only for specific indications [8]. According to the New Zealand Formulary amoxicillin is principally used in the treatment of community-acquired pneumonia, sinusitis and middle-ear infections. Amoxicillin with clavulanic acid is used in severe or complicated infections[9].

Box 1

Conditions where amoxicillin is the first-choice antibiotic:

  • Acute exacerbations of chronic obstructive pulmonary disease
  • Suspected or confirmed pneumonia
  • Acute otitis media
  • Group A streptococcal pharyngitis in patients at high risk of rheumatic fever (or penicillin V or IM benzathine benzylpenicillin tetrahydrate)
  • Sinusitis (persistent or severe)
  • Dental abscess (or metronidazole)
  • Prophylaxis of infective endocarditis prior to invasive dental procedure

Conditions where amoxicillin with clavulanic acid is the first-choice antibiotic:

  • Bites – human or animal
  • Diabetic foot infections

Source:

bpacnz. Antibiotics: choices for common infections. 2017. www.bpac.org.nz/antibiotics/guide.aspx.

Note: this list contains common conditions only and is not a complete list.

Antibiotic graph1 Apr 2019

12 percent of people (~460,000) who visited their GP were dispensed amoxicillin with clavulanic acid at least once in 2017.
  • Amoxicillin with clavulanic acid is a broad-spectrum antibiotic.
  • Use has reduced from 14 percent to 12 percent of people since 2015, a reduction of 61,000 people.
  • DHB variation is greater than two-fold, ranging from 8 percent to 17 percent.
 The dispensing of antibiotics specifically indicated for UTIs increased sharply with age and for people living in ARC.
  • The rate of antibiotics dispensed for a UTI varied according to where people live: for those aged 65–74 years, 6 percent of people in the community received an antibiotic for a UTI compared with 20 percent of those living in ARC.
  • In the community, dispensing was six-fold higher in women than men and was statistically significantly higher in those of European/Other ethnicity. Female ARC residents received 1.6-fold more UTI antibiotics than male ARC residents.
  • In people aged 65 and over, asymptomatic bacteriuria and UTIs can be common[10]. A Cochrane Review (2015) concluded there was no clinical benefit from treating asymptomatic bacteriuria[10].
On average, 32 percent and 33 percent of people were dispensed an antibiotic within 30 days of a medical and surgical admission, respectively.
  • This equates to antibiotics dispensed to 135,635 people following a medical discharge and 50,000 people following a surgical discharge.
  • Another Atlas domain presents data showing antibiotic dispensing following major surgery presents a similar result, whereby 32 percent of people were dispensed an antibiotic.
  • The level of DHB variation for both admission types was 1.3-fold.
  • It is recommended that, along with good infection prevention and control, antibiotics be prescribed only when needed, with the narrowest spectrum of antimicrobial activity. To prevent surgical site infection, NICE recommends antibiotics be used only in cases where there is an increased risk of infection; well-designed studies have shown a benefit of surgical antimicrobial prophylaxis[12]. Previous research in New Zealand concluded a significant proportion of antibiotics prescribed to patients discharged following surgery was inappropriate and recommended enhanced antimicrobial stewardship in this area[13]. It appears there may be a similar pattern in medical patients.
  • Graph 2 shows that 50 percent of medical discharges and 43 percent of surgical discharges had their antibiotic dispensed on the same or next day of discharge.

Antibiotic graph2 Apr 2019

Data sources and limitations

Data for this Atlas domain was drawn from the Pharmaceutical Collection, which contains claim and payment information from community pharmacies for subsidised dispensing. This collection does not allow for analysis of patients’ condition or the effectiveness of dose provided. This means it was not possible to assess the appropriateness or otherwise of prescribing. Unsubsidised dispensing is not included in this analysis; nor does it indicate if people took the medicine. As noted above, antibiotics dispensed under a PSO are not included. This means that children receiving an antibiotic through a school sore throat programme will not be included in the data.

The methodology is provided here (335KB, PDF).

Note: this analysis focuses on the number of people dispensed an antibiotic, not on the number of prescriptions (except for indicator 1b). We have used this approach because interpreting what the number of dispensed prescriptions might mean is complicated by differences in prescribing frequency, formulation and dose. We recommend further local analysis on people receiving antibiotics that accounts for these factors and the person’s clinical condition.

Questions this Atlas may prompt:

  • Why do rates vary between DHBs? How much can be explained by differences in patient population?
  • Does the pattern of prescribing seem appropriate? Is it consistent with guidelines and are these regularly reviewed?
  • What is the impact of crowding on rates of antimicrobial dispensing? Do DHBs with a higher prevalence of overcrowded housing also have higher incidence of infectious disease?

References

  1. Duffy E, Ritchie S, Metcalfe S, et al. 2018. Antibacterials dispensed in the community comprise 85%-95% of total human antibacterial consumption. J Clin Pharm Ther 43(1): 59–64.
  2. Metcalfe S, Bhawan S, Vallabh M, et al. 2019. Over and under? Ethnic inequities in community antibacterial prescribing. NZMJ 132(1488).
  3. Wennberg JE. 2011. Time to tackle unwarranted variations in practice. BMJ 342: d1513.
  4. Baker MG, Barnard LT, Kvalsvig A, et al. 2012. Increasing incidence of serious infectious diseases and inequalities in New Zealand: a national epidemiological study. Lancet 379(9821): 1112–9.
  5. Whyler N, Tomlin A, Tilyard M, et al. 2018. Ethnic disparities in community antibacterial dispensing in New Zealand, 2015. NZ Med J 131(1480): 50–60.
  6. Williamson DA, Zhang J, Ritchie SR, et al. 2014. Staphylococcus aureus infections in New Zealand, 2000-2011. Emerg Infect Dis 20(7): 1156–61.
  7. Hallsworth M, Chadborn T, Sallis A, et al. 2016. Provision of social norm feedback to high prescribers of antibiotics in general practice: a pragmatic national randomised controlled trial. Lancet 387(10029): 1743–52.
  8. bpacnz. Cold season: managing without antibiotics. Updated 26 June 2018. URL: www.bpac.org.nz/2018/cold-season.aspx (accessed November 2018).
  9. New Zealand Formulary (NZF). NZF v81. 2019. Available from: www.nzf.org.nz (Accessed March, 2019).
  10. Nicolle LE. 2016. Urinary tract infections in the older adult. Clin Geriatr Med 32: 523–38.
  11. Zalmanovici Trestioreanu A, Lador A, et al. Antibiotics for asymptomatic bacteriuria. Cochrane Database Syst Rev 2015, Issue 4, Art. No. CD009534. URL: www.cochranelibrary.com/cdsr/doi/10.1002/14651858.CD009534.pub2/epdf/full (accessed November 2018).
  12. NICE. Surgical site infection – prevention and treatment. London: NICE. URL: https://pathways.nice.org.uk/pathways/prevention-and-control-of-healthcare-associated-infections (accessed December 2018).
  13. De Almeida M, Gerard C, Freeman JT, et al. 2018. Inappropriate prescribing of antibiotics following discharge after major surgery: an area for improvement. NZ Med J 131(1475): 35–43.

Recommended reading

  1. Baker MG, Barnard LT, Kvalsvig A, et al. 2012. Increasing incidence of serious infectious diseases and inequalities in New Zealand: a national epidemiological study. Lancet 379(9821): 1112–9.
  2. Hallsworth M, Chadborn T, Sallis A, et al. 2016. Provision of social norm feedback to high prescribers of antibiotics in general practice: a pragmatic national randomised controlled trial. Lancet 387(10029): 1743–52.
  3. Ministry of Health and Ministry for Primary Industries. 2017. New Zealand Antimicrobial Resistance Action Plan. Wellington: Ministry of Health. URL: www.health.govt.nz/our-work/diseases-and-conditions/antimicrobial-resistance/new-zealand-antimicrobial-resistance-action-plan (accessed 19 March 2019).
  4. Norris P, Horsburgh S, Keown S, et al. 2011. Too much and too little? Prevalence and extent of antibiotic use in a New Zealand region. J Antimicrob Chemother 66(8): 1921–6.
  5. The Royal New Zealand College of General Practitioners.2015. Antibiotics and antimicrobial resistance: avoiding a post-antibiotic era. May 2015. Policy Brief. Issue 3. URL: https://oldgp16.rnzcgp.org.nz/assets/New-website/Advocacy/05.2015-Antibiotics-and-antimicrobial-resistance-Policy-brief-1.pdf (accessed March 2019).
  6. Whyler N, Tomlin A, Tilyard M, et al. 2018 Ethnic disparities in community antibacterial dispensing in New Zealand, 2015. NZ Med J 131(1480): 50–60.
  7. Williamson DA, Roos RF, Verrall A. 2016. Antibiotic consumption in New Zealand, 2006–2014. Porirua: The Institute of Environmental Science and Research Ltd. URL: https://surv.esr.cri.nz/PDF_surveillance/AntibioticConsumption/2014/Antibiotic_Consumption_Report_Final.pdf (accessed March 2019).

Resources

Patient Safety Week 4–10 November 2018 had a focus on infection prevention and control, with resources to encourage consumers and health professionals to ask: are you giving germs a hand? The aim was to encourage consumers and their families and whānau, to understand the importance of good hand hygiene for their health and the health of others; and to encourage health professionals to practise good hand hygiene.

Choosing Wisely has resources and supporting evidence for clinicians on antibiotic use. Recommendations include:

  • do not use antibiotics in asymptomatic bacteriuria
  • do not take a swab or use antibiotics for the management of a leg ulcer without clinical infection
  • avoid prescribing antibiotics for upper respiratory tract infection.

BPAC resources

Last updated 30/04/2019