General information about the ANZCTR and other trial registries

Understanding trial registration: requirements and definitions

Registering a trial

Registering with ANZCTR and other registries

Updating and reporting results

Using the registry

Participating in a trial


General information about the ANZCTR and other trial registries

What is the Australian New Zealand Clinical Trials Registry (ANZCTR)?

The ANZCTR is an online public registry of clinical trials, held at the NHMRC Clinical Trials Centre, University of Sydney.

It is a Primary Registry in the World Health Organization (WHO) Registry Network, which means that it fulfils certain criteria for content, quality and validity, accessibility, unique identification, technical capacity and administration.

The ANZCTR accepts both interventional and observational studies for registration from all countries and from the full spectrum of therapeutic areas including trials of pharmaceuticals, surgical procedures, preventive measures, lifestyle, devices, treatment and rehabilitation strategies and complementary therapies.

The ANZCTR accepts both interventional and observational studies from all countries and from the full spectrum of therapeutic areas including trials of pharmaceuticals, surgical procedures, preventive measures, lifestyle, devices, treatment and rehabilitation strategies and complementary therapies.

The registry was established in 2005 with funding from the Australian Government, through a National Health & Medical Research Council Enabling Grant. The ANZCTR is overseen by an Advisory Committee with wide representation from a variety of stakeholders including government, clinicians, the research community, journal editors, the pharmaceutical industry, regulators and consumers.

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What is the purpose of the ANZCTR and why it is important?

The ANZCTR supports a worldwide initiative to make all clinical trials publicly visible. Its key purposes include:

  • Improving research transparency: making details of all trials publicly available improves research transparency and helps to overcome publication bias and selective reporting, thereby enabling clinicians and consumers to make more informed decisions.
  • Facilitating trial participation: people interested in participating in a clinical trial and doctors investigating relevant trials for their patients have access to a reputable and comprehensive online register showing what trials are occurring across all areas of health, which may facilitate recruitment.
  • Avoiding duplication: improving awareness of similar or identical trials will make it possible for researchers and funding agencies to avoid unnecessary duplication.
  • Identifying research areas: describing clinical trials in progress can make it easier to identify gaps in clinical trials research.
  • Promoting research collaboration: enabling researchers and health care practitioners to identify trials in which they may have an interest could result in more effective collaboration among researchers.
  • Improving trial quality: registries checking data as part of the registration process may lead to improvements in the quality of clinical trials by making it possible to identify potential problems (such as problematic randomisation methods) early in the research process.

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Are there any other Australian or New Zealand clinical trials registries?

The ANZCTR is the only Primary Registry in the WHO Registry Network in Australia and New Zealand. The ANZCTR displays trials registered directly with the ANZCTR and those from ClinicalTrials.gov with recruitment sites in the region.

The ANZCTR is the primary data source for clinical trial information displayed on the consumer-friendly Australian Clinical Trials website (www.australianclinicaltrials.gov.au) managed by the Australian government and the Australian Cancer Trials website (www.australiancancertrials.gov.au) managed by Cancer Australia.

Other organisations in Australia and New Zealand may maintain their own registers on specific disease areas. The Therapeutic Goods Administration (TGA) maintains a database of therapeutic goods that can be supplied in Australia.

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Are there other international clinical trial registries?

Yes. There are currently 17 other Primary Registries in the World Health Organization Registry Network. These registries meet international standards for quality, transparency and accessibility.

To view the full list, visit WHO Primary Registries.

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Is there a charge to register a study on the ANZCTR?

No – registering a study on the ANZCTR is free. There are no charges for submitting or updating trial information.

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Understanding trial registration: requirements and definitions

Is registration of clinical trials mandatory in Australia or New Zealand?

In practice – yes, but not by law. While there is no legal requirement in Australia or New Zealand, clinical trial registration is required before the first participant is enrolled as outlined below:

  • In Australia:
    • The National Statement on Ethical Conduct in Human Research (2025). Clause 3.1.7 states that any research assigning people to health-related interventions must be registered in a publicly accessible registry, conforming to international standards as per the World Health Organization, before the recruitment of the first participant. This is known as prospective registration
    • The Australian Code for the Responsible Conduct of Research (2018). Clause 4.6 states that research must be registered on a publicly accessible register complying with international standards
    • Funding body agreements require prospective registration (e.g. NHMRC, ARC, MRFF)
    • Most Human Research Ethics Committees (HRECs) require prospective trial registration
  • In New Zealand:
    • Registration is required for clinical trials to receive regulatory and ethics approvals
  • As per international standards:

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Does the registry meet the requirements of the International Committee of Medical Journal Editors (ICMJE)?

Yes. The ANZCTR has been recognised as an ICMJE-accepted registry since 2006.

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Who is responsible for registering a trial?

The responsibility lies with the trial sponsor or their authorised representative.

A sponsor is defined by the NHMRC and Therapeutic Goods Administration (TGA) as "an individual, company or institution or organisation which takes responsibility for the initiation, management and/or financing of a clinical trial". Sponsors may include:

  • Pharmaceutical or biotech companies
  • Government or international health agencies
  • Lead principal investigators (especially in academic or investigator-led trials)

For multi-site studies, the trial should be registered once only, not by each site.

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What is the sponsor responsible for?

  • Registering the trial in a publicly accessible registry (e.g. ANZCTR)
  • Ensuring the accuracy and completeness of the registered information
  • Keeping the trial record up to date
  • Communicating the registration number and status to collaborators
  • Avoiding duplicate registrations for the same trial

An authorised representative may register the trial on the sponsor’s behalf, as long as they have permission to agree to the trial registration terms.

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What studies need to be registered?

Studies that meet the WHO/ ICMJE definition of a clinical trial:

"A clinical trial is any research study that prospectively assigns people to one or more health-related interventions to measure effects on health outcomes."

This includes medicines or vaccines, surgical procedures, medical devices, behavioural or lifestyle interventions and other interventions aimed at improving health.

If you are unsure whether your study qualifies – it is best to err on the side of caution and register it.

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When should studies be registered?

Start the registration process at least 8 weeks before recruitment, ideally at the same time as your ethics application.

If your study has already started, finished recruiting, or is completed, you can still register as a retrospective registration on the ANZCTR.

Important:

  • Some ethics committees require prospective registration
  • Many journals only accept results from studies registered before recruitment began

Regardless of journal requirements, you can still report your results on the ANZCTR.

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What does prospective registration mean?

Prospective registration means your trial is fully registered before the first participant is enrolled. This includes receiving your official registration number (i.e. ACTRN) from the ANZCTR.

A trial is not considered registered until this ACTRN is issued. Once registered, ANZCTR will email the account holder and principal investigator with the registration details.

Note: the ACTRN is different from the request number you receive when you first submit your application.

Example request number: 371456
Example registration number: ACTRN12616001299494

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What does retrospective registration mean?

Retrospective registration means your trial was registered after the first participant was enrolled.

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What does provisional registration mean?

Provisional registration means your trial is registered before ethics approval is granted, as long as it meets all other registration requirements.

Even without ethics approval, provisional registration:

  • is still considered registered
  • meets the requirements of the ICMJE
  • can be used to satisfy ethics committee requests for registration

Provisional registration is identified by:

  • a 'p' at the end of the registration number, e.g. ACTRN12615000923540p
  • a 'Provisional' watermark on the trial record
  • a 'Provisional registration' label at the top of the trial summary.

Once ethics approval is obtained and the record is updated, the status changes to full registration. This labelling system has been in place since 1 October 2015. Trials registered before this date had a 2-year grace period before these new labels were applied.

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Does the ANZCTR accept observational studies?

Yes – the ANZCTR accepts both interventional and observational studies.

For observational studies, make sure to select 'Observational' in the 'Study type' field during registration.

Note: interventional studies (clinical trials) are given priority in processing.

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Registering a trial

How do I register a trial?

Step-by-step instructions can be found on the How to register a trial page.

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What is recorded on the registry?

Each trial record can contain information about:

  • study objectives
  • main design features (e.g. randomisation)
  • sample size
  • interventions under investigation
  • outcomes being measured
  • recruitment status
  • whether individual participant data will be shared
  • trial documents: protocols, results and plain language summaries
  • principal investigators
  • contact details for trial-related enquiries

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My study has not been approved by an ethics committee yet. Can I still register it?

Yes. You can apply for provisional registration.

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Can a trial be removed from the ANZCTR once it has been registered?

No. Once a study is registered, it cannot be removed and will remain publicly viewable on the ANZCTR.

If your study is withdrawn, stopped early, or its status changes, we strongly encourage you to update the trial record to reflect the change.

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Can I register a study after it has started, closed to recruitment, or been completed?

Yes, you can still register your study on the ANZCTR even if recruitment has already started, recruitment has ended or the study is completed. This is called retrospective registration.

Important:

  • Some ethics committees require prospective registration
  • Many journals only accept results from studies registered before recruitment began so check their requirements before proceeding

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I submitted my application a few days ago - why have I not heard back?

If you are in Australia or New Zealand, we aim to respond within four working weeks.

If it has been longer, please check:

  • Your application status is 'Submitted' or 'Re-submitted' (not just saved as a draft)
  • You received a confirmation email from us

If you are applying from outside Australia or New Zealand, processing will take longer. We appreciate your patience.

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Registering with ANZCTR and other registries

Should I register my clinical trial on the ANZCTR, ClinicalTrials.gov or other registries?

To meet the requirements of the World Health Organization (WHO) and the International Committee of Medical Journal Editors (ICMJE), your clinical trial must be registered once on any WHO Primary Registry or ICMJE-accepted registry before enrolling your first participant.

You can register with: ANZCTR, ClinicalTrials.gov or another WHO/ICMJE-accepted registry.

Registering with any one of these is usually sufficient – unless a local authority (e.g. Human Research Ethics Committees (HREC)) asks you to register on another registry as well.

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My study is already registered on ClinicalTrials.gov but I need to register it on ANZCTR too. Can I copy the details to ANZCTR?

Yes. You can import some information from your ClinicalTrials.gov record into a new ANZCTR registration by following this process:

  1. Go to the ANZCTR homepage and click 'Register trial'
  2. Under the second option 'Register trial on ANZCTR that has already been registered elsewhere', click 'Proceed'
  3. Follow the steps until you reach the question: "Has this trial been registered on any of the following trial registries?"
  4. Tick the box for ClinicalTrials.gov and click 'Proceed'
  5. Enter your ClinicalTrials.gov registration number and click 'Next'
  6. Complete the rest of the form and submit it for review

Note: all imported information is editable. You must complete the ANZCTR form according to its data definitions and use the ‘i’ icons for help.

Once approved, you will receive an ANZCTR registration number (ACTRN).

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My trial is already registered with ClinicalTrials.gov. Can I add ANZCTR-specific information without registering again?

Yes. If your trial is registered on ClinicalTrials.gov and includes Australian or New Zealand recruitment sites, it will automatically appear on the ANZCTR.

However, some ANZCTR-specific fields may be missing because they are not available or extractable from ClinicalTrials.gov. These include:

  • Accrual to date
  • Australian recruitment details (e.g. hospitals)
  • Funding source
  • Sponsors and collaborators
  • Ethics approvals
  • Principal investigator and contact details
  • Brief summary (if not provided to ClinicalTrials.gov)

To add ANZCTR-specific information:

  1. Go to the ANZCTR homepage and click 'Register trial'
  2. Under the third option 'Add ANZCTR specific details to a ClinicalTrials.gov record', click 'Proceed'
  3. Confirm you are authorised and agree to the terms
  4. Enter your ClinicalTrials.gov registration number and click 'Proceed'
  5. Complete and submit the form

Note: for this case, data imported from ClinicalTrials.gov cannot be edited. The additional ANZCTR information will appear in a separate section at the end of the trial record.

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Does the ANZCTR accept submissions from countries other than Australia and New Zealand?

Yes, but with some conditions.

The ANZCTR encourages you to use your local WHO Primary Registry if one is available. To view the full list, visit WHO Primary Registries.

Because the ANZCTR is funded by Australia and New Zealand, we prioritise submissions in this order:

  • Studies with recruitment sites in Australia or New Zealand
  • Studies from countries without a WHO Primary Registry
  • Studies from countries that already have a WHO Primary Registry.

If your study is from outside Australia or New Zealand and has no local recruitment sites, there may be a delay in processing.

Important: all submissions must be in clear, concise English. Submissions that do not meet this standard may be rejected.

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Updating and reporting results

Do I need to update my trial information after registration?

Yes. You are responsible for keeping your trial registration details accurate and up to date, as per WHO requirements.

For step-by-step instructions, visit the 'Update a trial' page.

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Why are Steps 11 and 12 showing as empty on my registration page?

From October 2018, the ANZCTR introduced two new mandatory fields and must be completed by study investigators to order to comply with WHO minimum data set and ICJME policy:

  • Step 11 – Individual Participant Data (IPD) sharing
  • Step 12 – Study results

If they appear empty, it means they haven’t been completed yet.

To add this information, update your trial information. For step-by-step instructions, visit the 'Update a trial' page.

Once completed and approved by ANZCTR Staff, the approval date will appear on the public record. This does not affect your original registration date or whether your trial is marked as prospectively or retrospectively registered.

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How do I cite an ANZCTR study record in a publication?

Use the following format:

  • Australian and New Zealand Clinical Trials Registry [Internet]: Sydney (NSW): NHMRC Clinical Trials Centre, University of Sydney (Australia); 2005 - Identifier [Trial ID – ACTRN]. [Study title]; [registration date] [cited access date]; [page count]. Available from: [URL].

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How do I add trial results and documents to my trial record?

For step-by-step instructions, visit the 'How to report trial results' page.

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Using the registry

How can I access the registry?

The ANZCTR is freely accessible online at www.anzctr.org.au

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How do I search the registry?

For step-by-step instructions, visit the 'How to search for a trial' page.

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Can I download registration information?

Yes. You can download ANZCTR trial information in Excel format from the 'Search results' page.

Use the drop-down menu in the right-hand corner to choose one of the following options:

  • Download all ANZCTR trials in Excel, or
  • Download selected ANZCTR trial(s) to Excel

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Can I advertise on your website?

No. The ANZCTR website does not host or receive funding from advertising.

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Participating in a trial

How can I volunteer for a clinical trial?

For step-by-step instructions, visit the 'Thinking about a trial?' page.

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