Who owns and runs ISRCTN?

The ISRCTN registry is owned by ISRCTN, a company limited by guarantee set up in 2005. It is controlled by its Board of Directors, which delegates day-to-day management of the registry and database to the editorial team. It has the benefit of advice from an international advisory group. The ISRCTN registry is administered and the database is hosted and published on behalf of ISRCTN by BioMed Central, a publisher of open access peer-reviewed biomedical journals. BioMed Central is owned by Springer Science+Business Media.

What is the purpose of ISRCTN?

The ISRCTN was set up to register clinical trials, provide each one with a unique identifying number, and make the registry records publicly accessible and searchable. ISRCTN was founded in response to calls for the registration of trials as a condition of publication in a journal, and also in response to the recognition that the results of many trials remain unpublished and, without registration, remain hidden from the scientific record. For further discussion of the importance of trial registration, see Why Register.

What does ISRCTN stand for?

When the registry was started in the early 2000s, the acronym stood for International Standard Randomised Controlled Trial Number because the scope of the Registry was RCTs. Over the years the scope has been expanded (see scope below) and the acronym now means International Standard Registered Clinical/soCial sTudy Number. However the preferred name is simply ISRCTN and not the spelt out version.

What is the scope of ISRCTN?

The scope encompasses any study designed to assess the efficacy of health interventions in a human population. This includes both observational and interventional trials.

Which organisations does ISRCTN work with?

ISRCTN works with a number of stakeholders to improve the information publicly available about clinical trials. See our Resources page for more details.

Where does ISRCTN funding come from?

Some registries such as those that are part of the WHO network may not charge a fee because their activities are fully funded by grants. The ISRCTN registry is not funded by an overall government grant and is not the result of legislation. To ensure that clinical study information is listed freely, a fee is charged for publication of the information describing a study at inception.

What does the ISRCTN fee cover?

The fee covers the cost of maintaining a public registry which is free to access. The fee is set at a level which enables the ISRCTN editorial staff to maintain the registry, and to support researchers in providing complete information, including patient-friendly content.

The fee per trial is paid either by trialists themselves or by the institutions they belong to. The main UK funders of health research regard this fee as an allowable research cost.

For the current fee, please read the section entitled 'What is the fee for registration'.

How and when to obtain an ISRCTN

How do I obtain an ISRCTN?

To apply for an ISRCTN, click on Register on the home page or go to the login section. After login the application has 4 stages: trial details, contacts, sponosrs/funders, payment agreement. Details for all fields are in the Definitions page. Once your application has been received, a member of the ISRCTN editorial team will contact you with any questions on the details of your study. Provided your study details are in line with editorial policies and we have received payment, we will assign an ISRCTN and will include your record immediately in the ISRCTN registry. Submission of a record to the ISRCTN registry assumes that the applicant has read and agreed to the terms and conditions for ISRCTN trial registration

When should a study be registered?

A study can be registered at any stage and it is never too late or too early to register. However guidelines strongly recommend that studies be registered before patient enrolment begins, and some journals require prospective registration if they are to publish a study. As the ISRCTN registry holds a system-generated date of application as well as the trial start and end dates, the records will show whether the study was registered retrospectively or prospectively.

Which studies should be registered?

The ISRCTN registry provides ISRCTNs for any clinical trial designed to assess the efficacy of health interventions in a human population. This includes both observational and interventional trials. All designs are eligible.

Should pilot studies be registered?

Although not all pilot studies go on to become full trials, we recommend that pilot studies should be registered provided the study is designed to assess the efficacy of a healthcare intervention(s).

What happens when the pilot study becomes the main study?

If the pilot study has already received an ISRCTN, there is no need to make a new submission as long as the main study has the same participant(s) and intervention(s). A new ISRCTN is required if the full trial will study different groups of patients (i.e. not the same participant[s] and intervention[s] as in the pilot study). Please contact the ISRCTN editorial team with any questions on whether the main study requires a new ISRCTN.

How do I decide whether the study requires more than one ISRCTN?

Please contact the ISRCTN editorial team for any special case.

How long will it take to obtain an ISRCTN?

Once you have submitted your application, the ISRCTN editorial team will review your application within two working days and request any further details if necessary. Getting an ISRCTN with inclusion in the ISRCTN registry then depends on speed of payment.

Using the ISRCTN

When do I use an ISRCTN?

The ISRCTN should be recorded on all study documentation (e.g. protocol, trial forms, patient leaflets, reports, etc.). It should be quoted where appropriate in publications, conference presentations, correspondence relevant to the study and references to the study (e.g. new grant applications). If the trial is also registered in another (e.g. a specialist) registry, the ISRCTN should be quoted in the other registry. This will aid in de-duplications between registries. You should notify study co-funders and other sponsoring partners (e.g. companies supplying drugs or other materials to the trial, overseas co-operating or collaborative partners etc.).

Note that the ISRCTN does not replace the study acronym. Nor is the trial acronym a replacement for the ISRCTN. They should not be used interchangeably.

How do I refer to an ISRCTN?

When referring to an ISRCTN, there should be no space between the ISRCTN and the number itself.

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

All ISRCTN records have digital object identifiers (DOIs). To cite an ISRCTN trial record in the reference list of an article, please include named authors, year of publication and title of trial according to the convention of the publication, followed by the DOI, e.g.:

Mendelow, AD (2006): Surgical Trial in Lobar Intracerebral Haemorrhage. ISRCTN. http://dx.doi.org/10.1186/ISRCTN22153967

When do I use the ISRCTN itself and when do I cite the ISRCTN using the DOI?

If you are publishing the protocol or your results of a trial, quote the ISRCTN itself in the paper (e.g. in the abstract, or according to the journal’s guidelines). If you are referring to a trial registration record in the reference list of a paper, use a formal citation of the DOI.

What happens if there are two ISRCTNs for the same study?

If you notice that two or more ISRCTNs have been assigned to a trial, please contact the ISRCTN editorial team to inform them of this duplication. We will advise on the best solution and keep all relevant parties informed. ISRCTNs that are taken out of use will not be re-assigned to another study.

Registering a study

How do I register a study?

The ISRCTN application process has 5 steps (including login). See the Definitions page for details about the information required and go to the ISRCTN registry home page.

What information is needed to register my study?

The information requested is in line with the WHO data set. The full dataset for the ISRCTN registry is listed and explained in the Definitions page.

What if I don’t have all the information to hand?

You can save your application and return to it later. Please note that the details you enter are only kept for 3 months if you don’t complete your registration.

Can I register if I do not have ethics approval?

Even if your ethics approval is pending you can register with ISRCTN. During the submission, in the ethics approval field, please mention that your ethics application is in progress.

When you have received your ethics approval, please provide us with the name of your ethics board, the date of your ethics approval, and any reference numbers attached to this approval. This can be done after ISRCTN has been assigned to your study but should be updated before your first participant is recruited.

What is needed for the plain English summary?

Involving both patients and the public in research is becoming much more important. The ISRCTN registry aims to make content more accessible and easy to understand via a plain English summary. In order for the text to be written in very plain English (and not as an abstract for a peer-reviewed paper) ISRCTN recommends the use of the guidance developed and used by CancerHelp UK.

What do I have to do if my study is in the NIHR Portfolio database?

If your study has already been adopted by the NIHR and fulfils the eligibility criteria, the charge for registering your study with an ISRCTN will be invoiced to the Department of Health (NIHR).

Please note that your study could be adopted by the NIHR Portfolio, but may not meet the eligibility criteria e.g. it takes place elsewhere in the UK (i.e. Northern Ireland, Scotland or Wales), is an observational trial or is industry-supported/industry-sponsored. In this case you will have to pay the registration fee.

In order to register for ISRCTN through the NIHR Portfolio, you need to access your record on the NIHR Portfolio system and follow their instructions: tick yes to the question ‘Would you like to register this study for an ISRCTN’ and a message should provide information on whether your study is eligible for ISRCTN registration funded by the Department of Health - NIHR.

The NIHR Portfolio team will then send us your study for ISRCTN registration and you will not need to complete an application directly with us. The NIHR Portfolio team sends us weekly batches of studies for ISRCTN registration. We would usually receive the study within 1 to 2 weeks, if the above instructions are followed.

Checking and updating a record

How do I keep track of my studies?

By logging in and reviewing records displayed in My trials section.

Can I remove a record from the registry?

Once a study has been registered on the ISRCTN registry and publicly displayed on the website, the study will remain permanently on the register and cannot be deleted.

When does a record need to be updated?

The ISRCTN registry will update a record on request at any time. For example it may be appropriate to amend a record after ethics approval has been granted, to update the start and end dates of the trial if there has been a delay to the start of the trial, and to update the funder and sponsor details if the trial has been extended, and the previous funding has run out. If theWHO 20-item minimum dataset or the ICMJE guidelines evolve, it may also be necessary to update the record to ensure that it is in line with these guidelines.

Some of the older records in the ISRCTN registry may not be complete according to the current WHO 20-item minimum dataset. The ISRCTN editorial team regularly reviews records for completeness and will contact record providers if missing information is noted. If you request an update to an older record, the ISRCTN editorial team may take the opportunity to request a more extensive update to ensure that your record complies with current WHO/ICMJE guidelines.

How do I edit or update my trial record?

If you wish to update your ISRCTN record, please contact the ISRCTN editorial team. Please note that we cannot remove information from a record, or overwrite previous information, but will instead add any updated information, along with a date stamp to show when the changes were made to the trial record.

How will I know when my record has been updated?

Once you have contacted us with your requested update, a member of ISRCTN editorial team will make the updates to your trial record, and will inform you via email once these are done. A link to your record will also be provided to ensure that you can check over the changes.

How long will it take for my record to be updated?

An update to a record can usually be performed within two working days, depending on the size of the update


How do I pay for registration?

Trialists can pay by credit card, cheque or bank transfer (please note that we do not accept Western Union money transfers). However we strongly recommend that payments are made by credit card, as they generally clear more quickly than other forms of payment.

At submission you will be able to choose between 3 options:

  • Online payment: Please select if paying by debit or credit card
  • Offline payment: Please select if the registration fee is to be paid by bank transfer or cheque and fill in the required information. Bank transfer payments take up to 30 days after the transfer date to be confirmed by our Accounts Department. Payments by cheque can take up to 15 days to clear.
  • Funder pays: Please select if your funder has arranged an agreement with ISRCTN to pay for the registration directly
Are any taxes included in this charge?

Trialists resident in the UK are liable to pay Value-Added Tax (VAT, currently 20%). Trialists outside the UK do not pay VAT but are asked to provide a VAT number (where applicable).

Who is responsible for making the payment?

Whoever submits the application is responsible for making or arranging the payment (for instance, via his or her institution).

What is the fee for registration?

The fee is listed when you get to the payment section of the application process. The fee is GBP 220 per study (+VAT when applicable).

For organisations

Can an organisation set up an account with ISRCTN?

In order to expedite and streamline the process of registering studies with an ISRCTN, organisations can set up an institutional account in order to pay for trial registration monthly or using a prepay method. Studies from the organisation can then be registered immediately (pending any questions on the trial information), with no need to arrange payment before the ISRCTN is allocated. Please contact the ISRCTN editorial team for further information.

What reports do organisations receive?

Organisations with an ISRCTN account receive a yearly report of all trials registered within the year. Please contact the ISRCTN editorial team if you have special reporting requirements.

Finding trial information

How do I use the ISRCTN registry to find relevant studies?

You can search or browse the entire database – see our guidance

How do I download data from the ISRCTN registry?

You can retrieve data using the ISRCTN trial XML API. Please contact the ISRCTN editorial team for details.

Where has the mRCT (metaRegister of Controlled Trials) gone?

The metaRegister of Controlled Trials was a section of the ISRCTN website when first created. The aim bringing two sources of information: ISRCTN and ClinicalTrials.gov. This service is under review and in the meanwhile we advise to consult the following resources: