Safety and Quality > Our Work > Safety in e-Health > Cumulative hospital-level antibiogram

Health service organisations need to monitor antimicrobial use and resistance as a part of the National Safety and Quality Health Service Standards.

Antibiograms are tables of antimicrobial susceptibilities. They are used to inform local empirical antimicrobial recommendations and formulary management. Antibiograms should be available to clinicians and groups who are responsible for local antimicrobial therapy guidelines.

The Commission supports national standardisation of antibiograms at the hospital level.Specification for hospital-level cumulative antibiogram

In 2012 and 2013, the Commission developed a specification for hospital-level cumulative antibiograms for local surveillance of antimicrobial resistance. Specification of both the clinical and technical elements of cumulative antibiograms will support antimicrobial prescribing and antimicrobial stewardship in general. Specification of the cumulative antibiogram will also support national surveillance, mapping and monitoring of antimicrobial resistance.

Specification for Hospital Cumulative Antibiograms (this specification is currently being updated)

Development of the hospital-level cumulative antibiogram

First roundtable, 2012

The first expert roundtable in 2012 was to introduce the Commission’s proposal on the hospital-level cumulative antibiogram, and to understand current approaches to monitoring antimicrobial resistance.

Outcomes from the roundtable were that standardised antibiograms should:

  • Be appropriate for use by a hospital’s antimicrobial stewardship team to determine antibiotic policy for that hospital – antibiograms are not intended to be provided to a wider audience
  • Be consistent with guidelines from the Clinical and Laboratory Standards Institute
  • Comprise data from all wards of the hospital, including outpatients and emergency department
  • Provide a list of bacteria and a list of antimicrobials to be reported
  • Provide rules for accumulating numbers (for hospitals with small numbers of isolates) – for example, reporting by genus rather than species
  • Specify how many isolates were tested against later-line antibiotics, if susceptibility to later-line antibiotics is tested only because the species or genus is resistant to first-line antibiotics
  • Include standardised advice on commentary, which will be an intrinsic component of the antibiogram, and may include colour coding or symbols
  • Stratify results by patient age groups.

Second roundtable, 2013

The second expert roundtable reviewed and commented on the draft specification for the hospital-level cumulative antibiogram.

Participants included members from each state and territory, private hospitals, microbiology and laboratory sectors. Participants provided feedback on the draft and gave examples of antibiograms that were incorporated into the final draft.

The Expert Roundtable recommended that the Specification for Hospital-Level Cumulative Antibiograms be produced for each calendar year. The antibiograms should summarise susceptibilities of individual patients’ first isolates separately from non-urine (all other body sites), urine and blood isolates (if there are sufficient numbers to provide statistically reliable data).

Specifically, it was recommended that:

  • For non-urine isolates, for each calendar year, susceptibilities should be reported for at least the 5 most commonly isolated species, regardless of numbers isolated, and for all isolates where the number tested is greater than 30
  • For urine isolates, for each calendar year, at least the 3 most commonly isolated species with their susceptibilities should be reported, regardless of numbers isolated, and for all isolates where the number tested is greater than 30
  • Susceptibilities should be reported for any species isolated more than 30 times in blood cultures
  • For each year, the frequency of certain specified microorganism–antimicrobial susceptibility combinations should be listed (‘signal resistances’)
  • The cumulative antibiogram should include emergency department (and perhaps outpatient) isolates.