All studies that fall into the following definition of a clinical trial must now be registered on a publicly accessible database to be considered for publication (as required by International Committee of Medical Journal Editors, ICMJE):

Any research project that prospectively assigns human subjects to intervention and comparison groups to study the cause-and-effect relationship between a medical intervention and a health outcome.

If your research falls into this definition you must make sure you register your study before enrolment of the first patient, otherwise you may not be able to publish.  The ICMJE can provide a list of public database, examples are:

To register your trial on you need to go to the login page not the main public view page.

Please contact the JRCO Coordinator if you have any comments or queries about registering.

Register on a public database


The ICMJE's definition of a clinical trial is:

"Any research project that prospectively assigns human subjects to intervention and comparison groups to study the cause-and-effect relationship between a medical intervention and a health outcome."

The term "medical intervention" signifies any intervention used to modify a health outcome including drugs, surgical procedures, devices, behavioural treatments, process-of-care changes, and the like.

Each trial must have at least one prospectively assigned concurrent control or comparison group to require registration.

Within this definition, the ICMJE wants to ensure the public have access to all "clinically directive" trials (e.g. "Is drug X as effective as drug Y in treating heart failure?").

In addition, trials whose primary purpose is to affect clinical practice (phase 3 trials) will also require registration.

However, trials where the primary aim is to assess major unknown toxicity or establish pharmacokinetics (phase 1 trials) do not have to be registered.

Some trials may fall between these two extremes, i.e. trials whose particular goal is to investigate the biology of disease or to provide introductory data that may lead to larger, clinically directive trials. In this situation, unregistered trials will be considered by each journal editor on a case-by-case basis. 

The ICMJE recommend Investigators to err on the side of registration for trials falling in this catergory. The author of an unregistered trial will have to convince the editor of their reasons for not registering trials.

The ICMJE review this policy every two years.

ICMJE requirements

The ICMJE's requirements for an acceptable trial registry are that:

  • It must be electronically searchable 
  • Accessible to the public at no charge
  • Any researcher must be able to register their project
  • The registry must be not for profit
  • It must have in place means of ensuring the validity of the registration data

Minimum dataset

A recent meeting of the World Health Organisation (WHO) registration advisory group identified a minimal registration data set of 20 items, see the Data Set Table below.

The ICMJE has supported the minimum data set and adopted it as its requirement.

In order for a trial to be considered for publication, all 20 fields in the WHO minimal data set must be completed. A registration data set will be deemed inadequate if it is missing fields or fields contain uninformative terminology.

Minimal registration dataset table *
Unique Trial Number The unique trial number will be established by the primary registering entity (the registry).
Trial Registration Date The date of registration will be established by the primary registering entity
Secondary IDs May be assigned by sponsors or other interested parties (there may be none).
Funding Source(s) Name of the organisation(s) that provided funding for the study.
Primary Sponsor The main entity responsible for performing the research.
Secondary Sponsor(s) The secondary entities, if any, responsible for performing the research.
Responsible Contact Person Public contact person for the trial, for patients interested in participating.
Research Contact Person Person to contact for scientific inquiries about the trial.
Title of Study Brief title chosen by the research group (can be omitted if the researchers wish).
Official Scientific Title of Study This title must include the name of the intervention, the condition being studied, and the outcome (e.g., The International Study of Digoxin and Death from Congestive Heart Failure).
Research Ethics Review Has the study at the time of registration received appropriate ethics committee approval (yes/no)? (It is assumed that all registered trials will be approved by an ethics board before commencing.)
Condition The medical condition being studied (e.g., asthma, myocardial infarction, depression).
Intervention(s) A description of the study and comparison/control intervention(s) (For a drug or other product registered for public sale anywhere in the world, this is the generic name; for an unregistered drug the generic name or company serial number is acceptable). The duration of the intervention(s) must be specified.
Key Inclusion and Exclusion Criteria Key patient characteristics that determine eligibility for participation in the study.
Study Type Database should provide drop-down lists for selection. This would include choices for randomized vs. non-randomized, type of masking (e.g., double-blind, single-blind), type of controls (e.g., placebo, active), and group assignment, (e.g., parallel, crossover, factorial).
Anticipated Trial Start Date Estimated enrolment date of the first participant.
Target Sample Size The total numbers of subjects the investigators plan to enrol before closing the trial to new participants.
Recruitment Status Is this information available (yes/no) (If yes, link to information).
Primary Outcome The primary outcome that the study was designed to evaluate Description should include the time at which the outcome is measured (e.g., blood pressure at 12 months)
Key Secondary Outcome The secondary outcomes specified in the protocol. Description should include time of measurement (e.g. creatinine clearance at 6 months).

* The data fields were specified at a meeting convened by the WHO in April 2004; the explanatory comments are largely from the ICMJE.

Our recommendation

We suggest that if you can afford the fee charged use Current Controlled Trials.

If not use , which is free of charge. It will accept any trial that meets the ICMJE definition of a clinical trial, regardless of where the trial is to take place. Please see our sub page ( for instructions on how to use the site.


Registration for subsequent publication of results

In September 2004, the International Committee of Medical Journal Editors (ICMJE) published an editorial aimed at promoting registration of all clinical trials on a publicly accessible database.

It stated that member journals will only consider a trial for publication if it has been registered before the enrolment of the first patient.

This policy applies to trials that start recruiting on or after July 1, 2005.

Current and ongoing trials that were not registered at inception will only be considered for publication if they are registered before September 13, 2005.

Where to register

The only registries that currently meet ICMJE criteria are and the ISRCTN Register.

The ICMJE anticipates that a number of additional registries will make changes that result in them also meeting the ICMJE criteria for acceptable registries and we will endeavour to publish them on this page.