For Professionals

How to present information about clinical trials to the public

Potential trial volunteers can search the UKCTG database of clinical trials and contact you directly about your trial.

At UKCTG, we get our data about individual trials from two WHO-approved trials registries. The aims of registries are to increase research transparency and reduce publication bias and selective outcome reporting. Those registries are:

  • the UK-based ISRCTN, which exists to help UK medical research organisations meet their trial registration requirements – in line with Health Research Authority stipulations

  • the US-based, which operates to meet US federal requirements and is funded by the federal budget. (Because is US-based, its format and editorial policies reflect US priorities.)

It is very important that when you register your clinical trial at one of these registries you use a lay-friendly style.

The clearer and more accessible your registration entry is, the more likely it is that a suitable trial participant will understand what you are trying to achieve in your trial, and contact you via UKCTG with a view to taking part.

Here is some guidance on how to include lay-friendly information in the two registries:

If you are registering your trial at ISRCTN

If you register a new trial with ISRCTN, you will be asked to supply a ‘Plain English Summary’ of your trial; see the definition of this on the ISRCTN site for more information. An editorial team will review this summary, and you may be asked for clarification.

We then use this information in the summary section on the UKCTG site.

Because the ISRCTN team works with you in this way, trials registered here tend to have good lay information on UKCTG.

But if your trial has already been registered and you do not feel that the plain English summary is easy enough to understand, you can contact ISRCTN’s editorial team at; they will amend the details as you request.

If you are registering your trial at

If you register a trial with, you should enter lay-friendly information into the field called "Brief Summary”. We then use this summary in the “summary” section on the UKCTG site.

If your trial has already been registered and appears on UKCTG, but the information in this field is too technical, you can correct it by following’s instructions on How to Edit Your Study Record.               

‘It’s important to provide lay-friendly information when you register a clinical trial’

ISRCTN preferred partner of the Department of Health / NIHR

ISRCTN has been collaborating with the Department for many years to help UK trialists meet 3 registration objectives:

ISRCTN has an agreement with the Department of Health to facilitate registration from the NIHR Central Portfolio Management System (CPMS). See criteria. After studies are listed in ISRCTN, researchers receive regular reminders at certain milestones to ensure that records are kept up-to-date.

By registering with ISRCTN, you will comply with national and international guidelines, benefit from editorial help, ensure information is up-to-date and bring your research to a wider audience.

Why does UKCTG show different records for the same study?

In order to contain as many high quality study records as possible, UKCTG uses data from three sources: two registries and a study management system. In some cases, studies may be registered on more than one of these sources at a time, if for example the trial’s main site is outside the UK. You can ascertain whether two (or more) records are duplicates by looking at the reference given on each record on the right side above the heading ‘Primary Trial ID Number’. A trial ID number is the unique identifier allocated by a registry to a study and necessary for publication.