Trial Review

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Trial registered on ANZCTR


Registration number
Help: Registration number
ACTRN12626001220358
Ethics application status
Help: Ethics application status
Approved
Date submitted
Help: Date submitted
7/09/2026
Date registered
Help: Date registered
2/10/2026
Date last updated
Help: Date last updated
2/10/2026
Date data sharing statement initially provided
Help: Data sharing statement date
2/10/2026
Type of registration
Help: Type of registration
Prospectively registered

Titles & IDs
Public title
TOPAS: TOPicAl non-Steroidal anti-inflammatory drug + self-care advice with heat pack vs self-care advice with heat pack alone on severity of acute low back and neck pain
Scientific title
Topical Diclofenac Gel for Acute Non-Specific Low Back or Neck Pain: A Decentralised Pragmatic Randomised Controlled Trial Assessing Pain Severity
Additional trial identifiers [1] 318377 0
TOPAS
Universal Trial Number (UTN)
Trial acronym
TOPAS
Related trial records

Health condition
Health condition(s) studied:
Back pain 343517 0
Neck pain 343518 0
Condition category
Condition code
Musculoskeletal 339621 339621 0 0
Other muscular and skeletal disorders

Intervention/exposure
Study type
Interventional
Description of the intervention or exposure
Participants will be randomised 1:1 to either the topical group (14 days’ worth of topical - diclofenac gel 11.6 grams (~2 grams or 1 teaspoon) applied 4 times per day) + self-management, or self-management alone. Drug use will be assessed by patient report by using a pain and medicine use electronic diary. The study drug is available over-the-counter, and will be delivered via courier to the participant's home after the participant is screened and consented via a telehealth appointment.

Advice on guideline-endorsed self-management will be provided in the form of a handout developed by the Agency for Clinical Innovations’ (ACI) for those with low back pain and a handout developed by Arthritis Australia for those with neck pain, plus a single heat wrap. The advice handouts include reassurance of a likely positive prognosis, advice to keep moving, and advice on when to seek urgent care. The heat wrap is single use but will come with advice to seek out more heat wraps or a multi-use heat pack if they found the heat to be effective.
Intervention code [1] 335268 0
Treatment: Drugs
Description of the comparator or control
The control group will receive a self-management advice handout plus a heat wrap
Control group
Active

Outcomes
Primary outcome [1] 346794 0
Pain Severity
Timepoint [1] 346794 0
Completed 3 times per day (approx. morning, midday, evening) across the first 3 days to calculate Area Under the Curve, starting from receipt of the trial medicine
Secondary outcome [1] 467538 0
Pain severity
Timepoint [1] 467538 0
Day 7, 14 and months 1 and 3 after receipt of medicine
Secondary outcome [2] 467539 0
Use of medicines for back pain (other than the provided topical NSAID)
Timepoint [2] 467539 0
Baseline, days 3, 7 and 14, and months 1 and 3 after receipt of medicine
Secondary outcome [3] 467540 0
Use of other healthcare for back pain (e.g. GP, physio, Xray, heat packs)
Timepoint [3] 467540 0
Baseline, days 3, 7, and 14, months 1 and 3 after receipt of medicine
Secondary outcome [4] 467541 0
Physical Function
Timepoint [4] 467541 0
Baseline, days 3 and 14, and month 3 after receipt of medicine
Secondary outcome [5] 467542 0
Quality of Life
Timepoint [5] 467542 0
Baseline, day 14 and month 3 after receipt of medicine
Secondary outcome [6] 467543 0
Adverse events
Timepoint [6] 467543 0
Day 7, and 14 after receipt of medicine (not asked again after end of treatment period)
Secondary outcome [7] 467544 0
Treatment satisfaction
Timepoint [7] 467544 0
Day 14 after receipt of medicine

Eligibility
Key inclusion criteria
- Adults (18+) with acute low back pain (pain between the 12th rib and natal cleft) or neck pain (pain between shoulder and base of skull). Acute is defined as pain lasting <3 months.
- People with a flare of a chronic LBNP, defined as “a worsening of your condition that lasts from hours to weeks that is difficult to tolerate and generally impacts your usual activities and/or emotions”, or an expressed desire to use a medicine in the short term.
- Pain is of at least “mild” pain severity, as measured by adaptations of item 7 of the SF-36, ie, how much LBNP have you had in the last week? None/very mild/mild/moderate/severe/very severe).
- Willingness to give e-consent, and willingness to comply with the study.
- Currently in a location where they can receive a delivery from Door Dash or from Chemist Warehouse using their express delivery option (within 3 hours).
- Is contraindicated or not recommended for oral NSAIDs, e.g. has:
o A stomach or intestinal ulcer
o Bleeding from the stomach or bowel (symptoms of which may include blood in your stools or black stools)
o Kidney or liver problems
o Severe heart failure
o Heart bypass surgery
o Or prefers not to use oral NSAIDs for any other reason
Minimum age
18 Years
Maximum age
No limit
Sex
Both males and females
Healthy volunteers
No
Key exclusion criteria
- Chronic LBNP without flare or fluctuation
- Known allergy or hypersensitivity to topical diclofenac or any other anti-inflammatory medicine in topical or oral form, including aspirin
- Currently pregnant or breastfeeding
- Signs of a specific cause of back or neck pain such as
o Fever or chills indicating infection
o Severe pain that is worse at night
o Neurological deficits
o Progressive weakness
o Bowl or bladder dysfunction
o A recent trauma might that indicate a fracture
o Sudden unexplained weight loss

Study design
Purpose of the study
Treatment
Allocation to intervention
Randomised controlled trial
Procedure for enrolling a subject and allocating the treatment (allocation concealment procedures)
Central randomisation
Methods used to generate the sequence in which subjects will be randomised (sequence generation)
We will use the e-randomisation module on REDCap
Masking / blinding
Open (masking not used)
Who is / are masked / blinded?



Intervention assignment
Parallel
Other design features
Phase
Phase 4
Type of endpoint/s
Statistical methods / analysis

Recruitment
Recruitment status
Not yet recruiting
Date of first participant enrolment
Anticipated
30/11/2026
Actual
Date of last participant enrolment
Anticipated
1/12/2027
Actual
Date of last data collection
Anticipated
1/03/2028
Actual
Sample size
Target
256
Accrual to date
Final
Recruitment in Australia
Recruitment state(s)
ACT,NSW,NT,QLD,SA,TAS,WA,VIC

Funding & Sponsors
Funding source category [1] 322939 0
Government body
Name [1] 322939 0
NHMRC
Country [1] 322939 0
Australia
Primary sponsor type
University
Name
University of Sydney
Address
Country
Australia
Secondary sponsor category [1] 325875 0
None
Name [1] 325875 0
Address [1] 325875 0
Country [1] 325875 0

Ethics approval
Ethics application status
Approved
Ethics committee name [1] 321365 0
The University of Sydney Human Research Ethics Committee
Ethics committee address [1] 321365 0
Ethics committee country [1] 321365 0
Australia
Date submitted for ethics approval [1] 321365 0
Approval date [1] 321365 0
27/08/2026
Ethics approval number [1] 321365 0

Summary
Brief summary
Trial website
Trial related presentations / publications
Public notes

Contacts
Principal investigator
Name 153498 0
Dr Caitlin Jones
Address 153498 0
Insitute for Musculoskeletal Health, 77-79 Parramatta Road, Camperdown, NSW 2050
Country 153498 0
Australia
Phone 153498 0
+61 2 8238 2437
Fax 153498 0
Email 153498 0
[email protected]
Contact person for public queries
Name 153499 0
Caitlin Jones
Address 153499 0
Insitute for Musculoskeletal Health, 77-79 Parramatta Road, Camperdown, NSW 2050
Country 153499 0
Australia
Phone 153499 0
+61 2 8627 6262
Fax 153499 0
Email 153499 0
[email protected]
Contact person for scientific queries
Name 153500 0
Caitlin Jones
Address 153500 0
Insitute for Musculoskeletal Health, 77-79 Parramatta Road, Camperdown, NSW 2050
Country 153500 0
Australia
Phone 153500 0
+61 2 8627 6262
Fax 153500 0
Email 153500 0
[email protected]

Data sharing statement
Will the study consider sharing individual participant data?
No
No IPD sharing reason/comment: We do not currently have ethical approval to share IPD



What supporting documents are/will be available?

No Supporting Document Provided


Results publications and other study-related documents

Documents added manually
No documents have been uploaded by study researchers.

Documents added automatically
No additional documents have been identified.