Definitions

For guidance on filling in the ISRCTN study registration form, please refer to the relevant terms below (listed alphabetically).

Where “(WHO)” is displayed, this indicates that the data is required by the World Health Organization (WHO) as one of the 30 items that must be included in a study record for the study to be considered fully registered. 

Please note that, once you have submitted your study for registration, it enters the ISRCTN in-house editorial system, and you will no longer be able to make changes to the record yourself. If you would like any changes to be made after registration, please use the update request form or email us at info@isrctn.com quoting your study ID, and we will do this on your behalf.

Audit Trail

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. After a study is registered 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 record.

ClinicalTrials.gov number (WHO)

If your study is also registered in the ClinicalTrials.gov database, enter it in the Secondary identifying numbers field using the drop-down menu. The format is NCT12345678.

Completion date (WHO)

The date of study completion should be stated in your study protocol. In many cases, it is expected to be when the final data for a study were collected (commonly referred to as, "last subject, last visit"). Please give the anticipated or actual completion date for the study in the format dd/mm/yyyy.

Contact email address (WHO)

If possible, you should supply an institutional, or work-based, email address rather than a personal email address. If you are a study contact, your email address will be displayed publicly.

Contact ORCID ID

An ORCID ID is a unique digital code for researchers that can be used to identify all their publications and grant applications. If you do have one, please enter it here. If you do not and you are interested in obtaining one, you can go to the ORCID website for further information.

Contact privacy

In circumstances where there may be a risk of undue harassment if an individual’s name or contact information is publicly disclosed, the telephone number and email address can be recorded within the registry for use by the registry but not made publicly available. Assessment of the potential risk is on a case-by-case basis at the discretion of the registry.

Contact type (WHO)

The contact for public queries is the person who will respond to general queries, including information about the current recruitment status. There must be clearly assigned responsibility for scientific leadership to a named Principal Investigator (ISRCTN uses the term ‘principal investigator’ as this is the term used for the lead researcher in all other locations except the UK. As an international registry we use the international naming convention). The PI may delegate responsibility for dealing with scientific enquiries to a scientific contact for the study. This contact for scientific queries should be listed in addition to the PI. You can add multiple contacts by clicking on "Add".

The information provided here is functional and not personal, it is recommended to provide institutional and not personal information. By providing this information the registrant consents that the information provided can or may be published on a public website.

Countries of recruitment (WHO)

Please select all the locations where recruitment for the study is expected to take place. If you are registering a study taking place in the UK, it may be eligible for inclusion in the NIHR Clinical Research Network Portfolio database (further information).

Date of final enrolment (WHO)

The anticipated or actual date of enrolment of the final participant.

Date of first enrolment (WHO)

The anticipated or actual date of enrolment of the first participant. If your study is registered before or on the date of first enrolment, it will be listed as 'prospectively registered'. If your study is registered after the date of first enrolment, it will be listed as 'retrospectively registered'. The study is registered once the registration fee payment has been received.

Drug/device/biological/vaccine name(s) (WHO)

Many studies involve the administration of a drug, biological, vaccine or device. Please enter the name(s) of all drugs, biologicals, vaccines or devices being administered in the study, including active controls. Where possible, include the International Nonproprietary Names (INN) or other generic names of drugs and biologicals to aid searching. You must complete this field if you have described your intervention type as a drug, biological/vaccine or device.

Ethics approval (WHO)

In general, any research that involves human participants, human tissue or human data should obtain ethics approval before it begins, and regulations will vary from one country to another. If you have received ethics approval, please provide the date of approval, the full name of your research ethics committee (REC; providing an English translation of the name if appropriate), the contact details of the REC (postal address with postcode, telephone number and email address), and any REC reference numbers attached to the approval. For a multi-centre study, please provide the details for your lead centre only. For international studies, if you have a lead centre in each country then please provide details for each lead centre. If you do not have ethics approval yet, then please enter details of when and which ethics committee you plan to submit to.

EudraCT/Clinical Trials Information System (CTIS) number (WHO)

If your study is also registered in EudraCT or CTIS and you have a unique EudraCT/CTIS number, enter it in the Secondary identifying numbers field using the drop-down menu. The format is YYYY-123456-78 for EudraCT and EU-CT 2022-50xxxx-xx-xx for CTIS.

Final enrolment number (WHO)

This is the number of participants that the study has enrolled. This should include all participants enrolled in the study, regardless of any attrition after enrolment.

Health condition(s) or problem(s) studied (WHO)

Please provide a short description (maximum one sentence) of the disease, health condition or healthcare domain being studied. If the study is conducted in healthy human volunteers belonging to the target population of the intervention (e.g. preventive or screening interventions), enter the health condition(s) or problem(s) being prevented. If you would like to add more information on the disease being studied, then this information can be placed in the study objectives field.

Examples:
Cardiovascular disease
Cardiovascular disease and co-morbid type 2 diabetes

Healthy volunteers allowed (WHO)

To indicate if the study is conducted in healthy human volunteers not belonging to the target population (e.g. a preliminary safety study), check the yes/no box as appropriate.

Individual participant data (IPD) sharing statement (WHO)

Individual participant-level data (IPD), also known as ‘raw data’, is collected during your study. In compliance with the June 2017 ICMJE statement, your data-sharing intentions are expected to be stated at study registration as well as at manuscript submission. A growing number of journals encourage authors to make materials they describe in their study protocols freely available to any scientist wishing to use them, in accordance with relevant guidance and legislation on data protection and participant confidentiality (see BMC’s policy).

Do you plan to share individual participant data? Indicate if you plan to share IPD by checking the yes/no box. Choosing yes will allow you to input one (or more) of the following statements, providing as many of the details in italics as possible.

The datasets generated during and/or analysed during the current study will be stored in a publicly available repository (please provide repository name/weblink)
The datasets generated during and/or analysed during the current study will be stored in a non-publicly available repository (please provide repository name/weblink)
The datasets generated during and/or analysed during the current study will be available upon request from (please provide contact name and email address)
The datasets generated and/or analysed during the current study will be published as a supplement to the results publication
The datasets generated during and/or analysed during the current study are not expected to be made available due to (please provide the reason)
The data-sharing plans for the current study are unknown and will be made available at a later date (you will be requested to add a data-sharing plan at a later date)

Please also provide details of the type of data that will be shared, when the data will become available and for how long, by what access criteria the data will be shared including with whom, for what types of analyses, by what mechanism, whether consent from participants was obtained, comments on data anonymisation, any ethical or legal restrictions, and any other comments

Interventions (WHO)/Methodology

The intervention refers to the treatment or action tested or observed in your study. Please enter the names of all treatments or actions, including the control (enter 'placebo' or 'no treatment' as applicable) and the method of how participants are randomised into the different arms (e.g. using a computer program), if applicable. Describe other details of the interventions as applicable (drug dose, frequency and route of administration, schedule for study visits and follow-up, etc.).

For observational studies, please provide a summary of your methodology, providing details of any tests to be run, observations made and other relevant information.

Intervention type (WHO)

Please select the intervention type from the drop-down menu that most accurately describes that used in your study. Options are as follows:

Behavioural: treatment that is designed to modify a person’s behaviour. This includes behavioural therapies, group therapies and relaxation techniques
Biological/vaccine: biological products used as medicines. This includes vaccines, blood and blood products, and human cells and tissues used for transplantation
Device: this includes instruments, apparatus, machines or implants, for example, surgical lasers, hearing aids and MRI equipment
Drug: a chemical substance used as a medicine and recognised in an official pharmacopeia. Examples would include antibiotics and drugs used in chemotherapy
Genetic: this includes gene therapies and identification of genes or polymorphisms involved in disease
Mixed: please select this option if multiple types of intervention are used
Procedure/Surgery: invasive or external procedures/therapies or external therapies used in medical treatment
Supplement: a product that has been developed to supplement the diet but is not in itself considered food. Examples would include minerals, herbs and amino acids
Other: Please select if the intervention is different to any listed above

Lower age limit, Upper age limit (WHO)

The lower and upper age limits refer to the respective minimum and maximum ages at which participants are eligible to be enrolled in the study. They are entered as a numerical value along with a unit (e.g., days, weeks, months, years).

Key exclusion criteria (WHO)

Describe the key characteristics that exclude potential participants from taking part in the study. Use a numbered list (e.g. 1. 2. 3.) with a new line for each exclusion criterion.

Key inclusion criteria (WHO)

Describe the key characteristics that all potential participants must have to take part in the study, including age range and sex. Use a numbered list (e.g. 1. 2. 3.) with a new line for each inclusion criterion.

Key secondary outcome(s) (WHO)

The secondary outcomes of a study are the data, or results, that answer questions relevant to the study but secondary to those assessed by the primary outcome(s). Key secondary outcomes are pre-specified in the protocol for formal statistical testing and interpretation. While any additional secondary outcomes are often exploratory or supportive in nature. For cancer drug studies, for example, a key secondary outcome might be the incidence of a certain adverse event. Please complete the fields with the outcome name, metric or method of measurement and the timepoint(s) or the duration over which the outcome will be monitored. A preview will appear when all fields are filled in. Please do not enter the actual results of these outcomes in this field.

An example of an outcome might be: Pain after surgery, measured using the visual analogue score (VAS) at 24, 48 and 72 hours after surgery.

You should refer to the COMET (Core Outcome Measures in Effectiveness Trials) initiative which aims to develop "core outcome sets", that are, agreed outcomes reported for all studies in a particular field and how these outcomes should be measured. See COMET for further information.

Payment method

After your study registration has been submitted, it will be processed by our in-house editorial team to ensure that all the required information is present and consistent. Once the record is complete and ready for publication, you will be required to pay a one-off fee of GBP250 + tax when applicable for the study to be registered with an ISRCTN and published online. This fee helps to cover the cost of editing and curation, ongoing maintenance, and permanent online hosting.

Please select the method of payment for the registration of this study from the drop-down menu. The options are as follows:

Online payment: Please select if paying with debit or with credit card. We would recommend that you choose this option if possible as this is the fastest method of payment. Your ISRCTN is assigned to your study immediately upon authorisation of payment. A receipt will be emailed to you within 10 days after the payment has been made.
Offline payment: Please select if you wish to pay by debit/credit card, bank transfer or cheque on receipt of an invoice. Please note that bank transfer payments can take up to 30 days to process and a cheque can take up to 15 days. Offline payments also carry an administrative surcharge of GBP20.
Funded registration: Please do not select this option unless you know that your funder has arranged an agreement with ISRCTN to pay for the registration directly (e.g. NIHR, HRA or Wellcome Trust).

Phase (if applicable) (WHO)

Drug studies are commonly carried out in a series of stages or phases. If your study is a drug/device/biological/vaccine study, please select which option is appropriate from the drop-down menu.

Phase 0 (exploratory trials): These involve a very small number of participants, usually fewer than 15. Investigators use a very small dose of medication to make sure it isn’t harmful to humans before they start using it in higher doses for later phases.
Phase I: These involve only small numbers of participants, often healthy volunteers, and they are used to find out the safe dose range for the drug and test for side effects
Phase I/II: These studies test the drug's general safety and appropriate dosage levels in participants with the targeted condition, often where it would be unethical to expose healthy volunteers to a drug expected to have side effects, such as a cancer chemotherapy drug
Phase II: These involve participants with the targeted condition, and the aim is to get an idea of safety and effective dose levels
Phase II/III: In these studies, the effect of the new treatment and the effectiveness of the treatment compared with another well-established treatment and/or placebo are investigated on a smaller scale than in Phase III
Phase III: This is the stage when a large-scale, randomised clinical trial takes place, where the drug being tested is compared with another well-established treatment and/or a placebo. The effect of the new drug on the disease being studied, its side effects and any possible longer-term effects that may develop are investigated.
Phase IV: These take place once the new drug has been given its marketing licence, meaning that it is now available for prescription. The safety, side effects and effectiveness of the drug are monitored while it is being used in clinical practice

Plain English summary of protocol

The plain English summary of protocol is mandatory for UK-recruiting studies. It describes the research to the non-expert public and should be written in easily understood plain English in under or around 1000 words. It should encapsulate your research and is the first item listed in the public view of a registered study record. We ask that you present the information using the following subheadings:

Background and study aims (a brief description of the disease or area of study and what is the objective/aim of the study)
Who can participate? (what is the age range and sex of the participants, can they only participate if they have a certain condition or if they are healthy volunteers?)
What does the study involve? (what interventions will be compared, will all participants receive the same treatment, and what measurements will be taken?)
What are the possible benefits and risks of participating? (what can participants gain from enrolling, are there any side effects of the treatments and if so, what are the symptoms?)
Where is the study run from? (which institution is managing the study?)
When is the study starting and how long is it expected to run for? (what are the dates of first and final enrolment?)
Who is funding the study? (who will be paying the costs that the study will incur during its lifecycle?)
Who is the main contact? (if this is the same as the contact in the record, please provide the name and email address only, if different to the contact in the record, please provide the name, the position they hold at the institution/organisation and their email address)

We acknowledge that some of the information required is already covered in the rest of the record apart from the background and study aims and potential benefits and risks, but please do not copy and paste information already in the record and do not paste in the abstract or results from an intended publication. Please instead give some thought to how you can present complex scientific information to non-experts to get the message across.

ISRCTN recommends the use of the following guidance developed and used by Cancer Research UK:

Order logically, to maximise natural flow. Don’t go into more detail than you need.
Shorten your sentences. Take out unnecessary words and cut out repetition.
Substitute simpler words and phrases: 'before' rather than 'prior to', 'if' rather than 'in the event of', 'how well X works' rather than 'efficacy of X', 'treatment' rather than 'intervention', 'study' rather than 'randomised controlled trial', 'dummy' rather than 'placebo'.
Active, not passive: 'participants will have chemotherapy' rather than 'the chemotherapy will be given to participants'. Phrase positively, not negatively where possible: Participants will come to the hospital every third week rather than 'Participants will not need to come to the hospital for 2 weeks out of 3'.
Include medical terms after the plain English term: 'Participants will have an operation to remove their prostate (a radical prostatectomy)'.
Include abbreviations after the full term: 'chronic lymphocytic leukaemia (CLL)'.
Use the same tense throughout.

The following ISRCTN records contain examples of what we would expect plain English summaries of protocol to include:
ISRCTN24760606
ISRCTN03408765

Primary outcome(s) (WHO)

The primary outcome(s) of a study are the data, or results, from which the main aim of the study can be assessed. These data are used to decide whether the primary study objective has been proven or the principal question answered. For cancer drug studies, for example, a primary outcome might be the size of a tumour or the level of a biomarker. Please complete the fields with the outcome name, metric or method of measurement and the timepoint(s) or the duration over which the outcome will be monitored. A preview will appear when all fields are filled in. Please do not enter the actual results of the outcome in this field.

An example of an outcome might be: Pain after surgery, measured using a visual analogue score (VAS) at 24, 48 and 72 hours after surgery.

You should refer to the COMET (Core Outcome Measures in Effectiveness Trials) initiative which aims to develop 'core outcome sets', that are, agreed outcomes reported for all studies in a particular field and how these outcomes should be measured. See COMET for further information.

Public title (WHO)

The public title is intended for the lay public in easily understood plain English. It should be brief but contain enough information so that a member of the lay public would easily understand the main aim of the study.

Purchase order number/reference numbers

If you intend to pay the registration fee on receipt of an invoice (offline payment), you may need a purchase order (PO) from the finance department of your institution before an invoice can be paid. Check with them and enter the reference our invoice should quote in this field before the invoice is requested.

Scientific title (WHO)

The scientific title is intended for use in grant and ethics applications. It should be in the PICO format, containing information on the Participants, Intervention(s), Comparisons and Outcomes of the study. Include the study acronym for your study, if available, and use upper case letters for the corresponding letters in the title wording.

Secondary identifying numbers (WHO)

This field is for any reference numbers given to the study by the researcher, the source(s) of monetary or material support or sponsor etc. Use the drop-down menu to enter study IDs from any other register (see above for EudraCT/CTIS and ClinicalTrials.gov definitions), NIHR and Wellcome Trust grant numbers. UK Integrated Research Approval System (IRAS) and Central Portfolio Management System (CPMS) should be included here.

Observational study design

Use the drop-down menu to choose the design of your observational study:

Case crossover study: involves comparing participants’ exposure status during a time period just before an event with their exposure status during other control time periods, allowing each participant to serve as their own control
Case-control study: a study in which a group of participants with a disease or variable of interest is compared with a control group that doesn’t have the disease/variable
Case series: a study that follows a group of participants with a particular condition or variable of interest that have been treated in a similar way, over a specified period
Cohort study: a type of longitudinal study in which a specific set of observations are taken for a specific group of participants (a cohort) over a long period of time
Cross-sectional study: a study where data is collected and analysed for a specified group of participants at one specified point in time
Ecological study: a study looking at the effect of risk-causing variables (for example, environmental factors) on health or other outcomes in a specific population group
Epidemiological study: a study that compares two groups of participants that are similar in every way other than for one variable, for example, two demographically similar populations living in similar conditions other than one population is exposed to a potentially damaging chemical
Longitudinal study: a study where a specific set of observations are taken over a long period of time
Nested case-control study: this is a variation of the case-control design in which a cohort of participants at risk of developing a disease is identified, and cases are those who develop the disease, while controls are selected from the same cohort who have not developed the disease at the time of case identification
Other (please specify): only select if the study design is not listed above (note that case reports, meta-analyses, systematic reviews, animal studies, and studies without outcomes measured in humans are not accepted). Please add a brief description of your study design to the free text box provided.

Study design (WHO) - interventional studies

Use the menus to choose the design of your interventional study:

Allocation:

Randomized controlled trial: A clinical trial with an intervention and control group, where allocation to a group is done randomly
Non-randomized controlled trial: A clinical trial with an intervention and control group, where allocation to a group is not done randomly, but by some other method
N/A: Single-arm study

Masking:

Blinded: masking used
Open: masking not used

Control:

Active: an active substance
Dose comparison: different dose(s) of the same drug used
Historical: individuals treated in the past are used as a comparison group
Placebo: an inactive substance
Uncontrolled: no control intervention used

Assignment:

Cluster: a randomised controlled trial where groups of participants (clusters) are assigned to different intervention and control groups See example
Crossover: a randomised controlled trial where, at a predefined point, the arms of the study swap so that each group undergoes all interventions but in a different order
Factorial: a clinical trial in which groups of participants receive one of several combinations of therapies or interventions. For example, two-by-two factorial assignment involves four groups of participants, each receiving a different combination of two interventions or their controls
Parallel: a randomised controlled trial in which participants are assigned to one of two or more groups and remain in their assigned group for the duration of the study.
Sequential: where participants may be randomised to interventions in a specific order, often according to pre-specified decision criteria
Single: one therapy arm is available to all study participants
Other: If the above options are not relevant, use the free-text box to describe your study assignment

Purpose:

Basic science: to understand the fundamental aspects of phenomena without a specific application towards processes or products in mind
Device feasibility: the first attempts to test whether a device will (for example) provide the desired information in a clinical setting
Diagnostic: tests something used to identify or classify a condition
Health services research: investigates how healthcare services are organised, delivered, and financed
Prevention: tests something that prevents a condition developing
Screening: tests a way of identifying participants who might have a condition
Supportive care: when the primary intent is to maximise comfort and minimise side effects
Treatment: tests an intervention intended to improve the condition
Other: if the above options are not relevant, use the free-text box to describe your study purpose

Sex (WHO)

Please select the sex, the biological characteristics that define humans as female or male, of the participants taking part in your study from the drop-down menu.

Sponsor (WHO)

The primary sponsor is the organisation (rather than an individual) taking responsibility for ensuring that the design of the study meets appropriate standards and that arrangements are in place to ensure appropriate conduct and reporting. The sponsor organisation should match an institution name from the Research Organization Registry (ROR) database if possible. If the name is not available in ROR enter the full name of the institution. You can add secondary sponsors by clicking on 'Add'.

Study acronym (WHO)

An acronym refers to an abbreviation of your scientific title. This can be made up from individual letters from your title or parts of a word from your title. Alternatively, you can supply a short name you use to refer to your study.

Example of an acronym: ECHO (Evidence for CHildren's Outcomes).

Source(s) of monetary or material support (WHO)

All studies need funding even if they are self-funded. Please list all source(s) of monetary or material support for this study, providing an English translation for names of institutions/organisations as appropriate. You can use the Crossref Funder Registry (formerly FundRef) functionality to select the names and contact details of major institutions/organisations. If the name of your institution/organisation does not appear in the list, or is an individual, input it manually. You can add multiple by clicking on "Add".

Study objectives (WHO)

The purpose of this field is for the inclusion of the principal aims, objectives, or questions addressed by the study. For observational studies, please enter a rationale for why the study is taking place.

You might find it useful to refer to the reporting guidelines appropriate for your study. SPIRIT provides guidelines to help improve the quality of interventional study protocols. CONSORT provides guidelines for randomized controlled trials. STROBE provides guidelines for observational studies. Please also refer to EQUATOR for further information on reporting of research studies.

Study outputs

The study outputs are defined as follows:

Protocol article: a link to the study protocol in a peer-reviewed journal
Results article: a link to the study results in a peer-reviewed journal
Abstract: a link to a conference abstract published in a journal
Basic results: an uploaded document containing the participant flow diagram and tables of the baseline characteristics, outcomes and adverse events - for further instructions see the 'Report your results' page
Book: a link to the study results published in a book
Dataset: a link to the participant-level data stored in a repository
Funder report: a link to a funder report of the study results
HRA research summary: a link to a research summary on the HRA website containing information extracted from the IRAS application form
Interim results article: a link to the interim study results in a peer-reviewed journal (i.e. not the final study results)
Other files: any other uploaded study documents that don’t fall into the other categories
Other publications: any other publications that don’t fall into the other categories (i.e. not containing the study results)
Other unpublished results: unpublished results that are not a preprint or basic results
PIS: the participant information sheet, either a link or an uploaded document
Plain English results: a plain English summary of the study results, e.g. a link to the Cancer Research UK website
Poster: a link to the study results in a poster presented at a conference
PPIE document: a Patient and Public Involvement and Engagement document, either a link or an uploaded document
Preprint: a link to the study results in a preprint publication (i.e. before peer review and publication in a journal)
Preprint (other): a preprint publication other than the protocol and results
Protocol (file): the study protocol in an uploaded document
Protocol (other): a link to the study protocol that is not published in a peer-reviewed journal
Protocol (preprint): a link to the study protocol in a preprint publication (i.e. before peer review and publication in a journal)
SAP: the statistical analysis plan, either a link (e.g. to a journal publication) or an uploaded document
Thesis: a link to a thesis (e.g. in a university repository) that contains the study results
Tissue/sample set: a link to instructions on how to access the samples held in a tissue bank
Trial website: a link to a website created for the study

Study participating centre

A study may take place in many countries and have many participating centres/sites. For sites in the UK, please provide the names of all the participating centres (individual sites, i.e. hospitals where the participants attend to take part in the study and not NHS trusts where the study is administered from). For sites outside the UK, please provide the name, country and postcode (or equivalent). If your study takes place in more than one country, you must include the details of at least one participating centre for each country listed, including the postcode. Please add all participating centres by clicking on 'Add'.

Target sample size at registration (WHO)

This is the number of participants that the study plans to enrol in total (across all arms and all sites if a multicentre study). Note: this field only accepts numeric characters.

Type of study (WHO)

Please select the type of study (interventional (WHO) or observational) from the drop-down menu.

VAT number

Getting a study ID may be subject to a local tax (for example, value-added tax or sales tax) depending on the applicant's country. Enter the relevant local tax number in this field.

Why did you choose ISRCTN to register your study?

Please tell us why you decided to register your study with the ISRCTN registry by selecting the most appropriate option from the drop-down menu. If selecting “Other (please specify)”, please give further information in the free text field that appears.

Previously registered a trial
The location of the trial
Publisher policy
Funding agency policy
Regulatory agency policy
Institution policy
Ethics committee policy
Regulatory body policy
Decision of principal investigator
Straightforward registration process
Expert scientific editing and curating
Other (please specify)