COVID-19 studies are our top priority. For all other studies, we recommend commencing the registration process concurrently with your ethics submission and allowing at least 8 weeks for registration to be completed from date of first submission as we are experiencing 4 week turn-around time in review of submissions and resubmissions. We currently do not have the capacity to expedite reviews.

Note also there are additional delays to review of updates. We appreciate your patience.

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been endorsed by the ANZCTR. Before participating in a study, talk to your health care provider and refer to this information for consumers
Trial registered on ANZCTR

Registration number
Ethics application status
Date submitted
Date registered
Date last updated
Date data sharing statement initially provided
Type of registration
Prospectively registered

Titles & IDs
Public title
Streamlining antibiotic allergy testing for elective surgery patients using smartphone based apps
Scientific title
PeRiopErative Penicillin/Cephalosporin AlleRgy TEsting - A phase II feasibility/safety randomised control trial to empower anaesthetists to risk stratify and de-label antibiotic allergy labels in the perioperative period using digital health solutions.
Secondary ID [1] 302281 0
Nil Known
Universal Trial Number (UTN)
Trial acronym
Linked study record

Health condition
Health condition(s) or problem(s) studied:
Penicillin Allergy 319025 0
Cephalosporin Allergy 319026 0
Antibiotic Allergy 319027 0
Condition category
Condition code
Inflammatory and Immune System 316981 316981 0 0

Study type
Description of intervention(s) / exposure
Pre-operative risk stratification and de-labelling of antibiotic allergy labels:

Aim: Develop and implement a point of care, smartphone app based beta-lactam allergy de-labelling tool in perioperative medicine and assess the safety and feasibility of this intervention.

Risk stratification of antibiotic allergy labels via a custom built smartphone app, based on a validated assessment tool. To be used by anaesthetists during pre-operative assessment.

Participants in pre-operative assessment clinic (PAC) with penicillin or cephalosporin allergy will be randomised to either the intervention arm or control arm. Those randomised to intervention arm will go on to be risk-stratified. Risk stratification is carried out by clinical staff within the PAC during a routine 20min consultation via the use of a smartphone application containing the validated Antibiotic Allergy Assessment Tool. Pre-operative assessment occurs between 1 week and 1 day prior to surgery.

Participants identified as having a 'low-risk' penicillin or cephalosporin allergy label will go on to be challenged with an oral dose of penicillin VK, amoxicillin or cefalexin and observed for 1 hour post. This challenge occurs on the same day, directly after risk stratification occurs.

Delivered by who and where:
Risk-stratification will be completed by anaesthetic specialist in pre-operative assessment outpatient clinic. Participants who go on to challenge will also be challenged with a dose of antibiotic and observed within the same outpatient clinic.
Intervention code [1] 318569 0
Treatment: Other
Comparator / control treatment
Participants randomised to the control arm will go on to receive standard of care and will be referred for allergy testing via the normal hospital based pathways. Standard of care in this context includes use of alternative antibiotics on the day of surgery and/or referral for further allergy testing post-surgery. This referral occurs on discharge from hospital.
Control group

Primary outcome [1] 325089 0
Feasibility of recruitment/intervention delivery:
a) Feasibility of intervention delivery defined as the proportion of patients randomised to the intervention arm who had the intervention delivered as per protocol
- Determined by audit of clinical notes
b) Feasibility of recruitment defined as the proportion of patients consenting to participation in the study as per protocol from eligible patients.
- Determined by audit of clinical notes
Timepoint [1] 325089 0
On the day of pre-operative assessment
Primary outcome [2] 325090 0
a) The proportion of patients with a penicillin allergy who experience an antibiotic associated adverse event and/or severe adverse drug reaction.
- Occurrence of adverse events will be determined from medical records
Timepoint [2] 325090 0
Assessed at two main time points:
a) On the day of pre-operative assessment and/or challenge
b) At the time of surgery and in the post-surgical period
Secondary outcome [1] 386823 0
Beta-lactam utilization in perioperative period (n, %). This would be assessed by examining patient medical records.
Timepoint [1] 386823 0
At time of surgery (1-4weeks after pre-operative assessment)
Secondary outcome [2] 386824 0
Surgical operating times (minutes). This would be assessed by examining patient medical records.
Timepoint [2] 386824 0
At time of surgery (1-4 weeks after pre-operative assessment)
Secondary outcome [3] 386825 0
Surgical site infections (n, %). This would be assessed by examining patient medical records.
Timepoint [3] 386825 0
1 month post-surgery
Secondary outcome [4] 388431 0
Post-intervention evaluation:
Satisfaction with the intervention assessed via semi-structured interviews in focus group discussions or one-on-one interviews. The COM-B / Behaviour Change Wheel frameworks will be adopted for analysis.
Timepoint [4] 388431 0
After completion of the intervention stage, 12-18months after the study begins.

Key inclusion criteria
Patients aged 18 years and above that are reviewed in the perioperative assessment clinic under the care of the orthopaedic surgery unit, having a reported penicillin or cephalosporin allergy label, and will require intravenous antibiotic therapy in planned perioperative care.
Minimum age
18 Years
Maximum age
No limit
Both males and females
Can healthy volunteers participate?
Key exclusion criteria
Patients aged < 18 years
Patients currently receiving beta-lactam antibiotic therapy
Previous referral or assessment by a specialist for beta-lactam allergy
Under the current care of an Allergy/Immunology specialist
Require non-beta-lactam antibiotics for an infection or colonization with an organism resistant to beta-lactam (eg MRSA, ESBL producing gram negatives)
Emergency or trauma orthopaedic surgery
Contraindication for oral penicillin provocation
• Patients receiving more than 10mg of prednisolone or
equivalent daily
• Patients receiving antihistamine therapies
• Patients with a history of drug-associated anaphylaxis or idiopathic urticaria/anaphylaxis

Study design
Purpose of the study
Allocation to intervention
Randomised controlled trial
Procedure for enrolling a subject and allocating the treatment (allocation concealment procedures)
Allocation is not concealed
Methods used to generate the sequence in which subjects will be randomised (sequence generation)
Permuted block randomisation via computer program
Masking / blinding
Blinded (masking used)
Who is / are masked / blinded?

The people administering the treatment/s

Intervention assignment
Other design features
Phase 2
Type of endpoint(s)
Statistical methods / analysis
The sample size calculations for this feasibility and safety study is based on the precision of
the estimates for the feasibility outcomes.

Feasibility considerations: We would like to be able to estimate the proportion of patients
randomized in the intervention arm to actually receive the intervention as per protocol with
sufficient precision. Recruiting 49 patients in the intervention arm of the study would provide
the precision (half-width of the 95% confidence interval) of 8% to estimate the underlying
proportion of patients treated per protocol to be 85% as per the definition provided earlier in
this protocol.

The sample size for stakeholder interviews in Stage 2: Post-intervention Evaluation, is
iteratively derived based on reaching data saturation: in qualitative research, data saturation
is usually reached with fewer than 15 interviews.

Safety considerations: We would like to be able to estimate the proportion of patients
experiencing adverse events casually related to the study in the intervention arm with sufficient precision. Recruiting 73 patients in the intervention arm of the study would provide the precision (half-width of the 95% confidence interval) of 5% to estimate the underlying proportion of patients experiencing any adverse event (See - serious adverse event or antibiotic associated adverse event definitions) to the study to be 5%.

Assuming 1:1 randomization between two study arms, we would randomize 150 patients
(sample size calculation to assessed safety requires 73 in each arm [146 total], total
randomized rounded to 150 total). in total, providing sufficient precision for both feasibility and
safety outcomes.

This sample size is feasible, as we assume that 9% of all screened patients will report a
penicillin allergy as per national data10, thus requiring us to screen up to 1750 patients. This
will be achieved by 4 centres each contributing approximately 40 patients out of their general
480 patient per year cohort.

Feasibility of intervention delivery and feasibility of recruitment will be reported as proportions
with respective 95% confidence intervals. The proportions of patients with a penicillin allergy
who experience an antibiotic associated adverse event and/or severe adverse drug reaction
as per protocol definitions will be reported by group with respective 95% confidence intervals
and compared using modified Poisson regression model with robust standard error estimation. Corresponding effect size will be reported as risk ratio with respective 95% confidence interval.

Secondary outcomes will be reported by group and compared using appropriate regression
models. Details of statistical analysis will be documented in a separate Statistical Analysis
Plan (SAP) that will be developed and finalized prior to the study database lock.

Recruitment status
Date of first participant enrolment
Date of last participant enrolment
Date of last data collection
Sample size
Accrual to date
Recruitment in Australia
Recruitment state(s)
Recruitment hospital [1] 17503 0
Royal Melbourne Hospital - City campus - Parkville
Recruitment hospital [2] 17504 0
Austin Health - Austin Hospital - Heidelberg
Recruitment hospital [3] 17505 0
The Alfred - Melbourne
Recruitment postcode(s) [1] 31234 0
3004 - Melbourne
Recruitment postcode(s) [2] 31232 0
3050 - Parkville
Recruitment postcode(s) [3] 31233 0
3084 - Heidelberg

Funding & Sponsors
Funding source category [1] 306708 0
Commercial sector/Industry
Name [1] 306708 0
Address [1] 306708 0
Building A, Level 1, 26 Talavera Rd
Macquarie Park NSW
Country [1] 306708 0
Primary sponsor type
Austin Health
145 Studley Rd
Heidelberg VIC 3084
Secondary sponsor category [1] 307438 0
Name [1] 307438 0
Address [1] 307438 0
Country [1] 307438 0

Ethics approval
Ethics application status
Ethics committee name [1] 306878 0
Austin Health Human Research Ethics Committee
Ethics committee address [1] 306878 0
145 Studley Rd
PO Box 5555
Heidelberg VIC 3084
Ethics committee country [1] 306878 0
Date submitted for ethics approval [1] 306878 0
Approval date [1] 306878 0
Ethics approval number [1] 306878 0

Brief summary
Antibiotic adverse drug reactions (ADRs), commonly known as "allergies", are a major burden on patients and hospitals. Currently, up to one in four Australian and American patients admitted to hospital will report an antibiotic "allergy" (so-called antibiotic allergy “labels” [AAL]), many of which limit appropriate antibiotic usage. In many instances, patients may undergo challenge with the antibiotic due to incorrect allergy reporting and recording. The nature of a patient’s antibiotic allergy and what antibiotics should be avoided are a common source of confusion for both doctors and patients alike. Penicillin allergy labels in the perioperative space have been associated with inferior patient (e.g. increased rates of periprosthetic infection), hospital (e.g. increased surgical time), and prescribing outcomes (e.g. vancomycin > cefazolin utilization), and conversely in observational and non-controlled studies penicillin allergy “de-labelling” has been associated with improved utilization of beta-lactams and patient outcomes. Further, whilst direct oral penicillin challenge has increasing observational evidence for safety and efficacy, it has not been applied to the perioperative assessment of orthopaedic patients reporting a penicillin allergy.

This project is a collaboration between Austin Health, Alfred Health and Royal Melbourne Hospital. The PREPARE study is a feasibility and safety randomized control trial examining feasibility and safety of enhanced antibiotic allergy assessment and penicillin allergy testing in the perioperative setting in orthopaedic surgery patients planned for elective surgery. The PREPARE study will examine the utility of decision support (via smartphone app) utilizing a validated Antibiotic Allergy Assessment Tool9 for patients reporting a penicillin allergy in the perioperative arena in identifying those patients appropriate for a direct oral penicillin challenge in the perioperative clinic. PREPARE hopes to provide a useful point of care toolkit to improve clinician antibiotic allergy knowledge, antibiotic prescribing and medication safety, subsequently benefiting patients, clinicians and hospital networks.
Trial website
Trial related presentations / publications
Public notes

Principal investigator
Name 105318 0
A/Prof Jason Trubiano
Address 105318 0
Department of Infectious Diseases
Austin Health
145 Studley Rd
Heidelberg VIC 3084
Country 105318 0
Phone 105318 0
Fax 105318 0
Email 105318 0
Contact person for public queries
Name 105319 0
Dr Joseph De luca
Address 105319 0
Department of Infectious Diseases
Austin Health
145 Studley Rd
Heidelberg VIC 3084
Country 105319 0
Phone 105319 0
Fax 105319 0
Email 105319 0
Contact person for scientific queries
Name 105320 0
Dr Joseph De luca
Address 105320 0
Department of Infectious Diseases
Austin Health
145 Studley Rd
Heidelberg VIC 3084
Country 105320 0
Phone 105320 0
Fax 105320 0
Email 105320 0

Data sharing statement
Will individual participant data (IPD) for this trial be available (including data dictionaries)?
No/undecided IPD sharing reason/comment
What supporting documents are/will be available?
No other documents available
Summary results
No Results