ICTRP search portal - search tips

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General Instructions

The Clinical Trials Search Portal provides access to a central database containing the trial registration data sets provided by the registries listed on the right. It also provides links to the full original records.

  • To facilitate the unique identification of trials, the Search Portal bridges (groups together) multiple records about the same trial. More information
  • It is possible to export the results of the search into XML.  More information
  • Crawling the ICTRP database requires a username/password. To request access to the crawling pages please send an email to ictrpinfo@who.int
  • A new field called 'Prospective registration' has been added to the ICTRP database, More details about this new field can be found here.
  • To search for studies with results, click on the filter “with results only”. After entering your search term, activate the filter, in order to quickly identify trials with results. This function can be used as well in the standard as in the advanced search.

Flags

  • Prospective Registration: When a trial is registered in a primary registry before the recruitment of the first patient. The ICTRP database flags prospective records by comparing the 2 fields 'date of registration' of the trial and 'date of first enrolment' of patients. Prospective is when (by ICTRP standards) the 'date of registration' field is prior to the 'date of first enrolment' field.
  • Results available: The ‘Results available’ field will appear as ‘Yes’ whenever at least one of the following fields ‘Results date posted’, ‘Results URL', ‘Results summary’ or the ‘Results outcomes’ holds the according information.
  • Orphan drugs: These are drugs used to treat extremely rare (“Orphan”) diseases. Clinical trials testing the use of such medications are flagged in the ICTRP with “Orphan Drug” based on a list of key words identified by Orphanet.
  • Gene editing: If a clinical trial registered in the ICTRP involves genome editing, it is flagged in the data base as a “Gene editing” trial. The flagging is based on the presence of key words related to gene editing in the text of the registration.

 

 

Standard Search

Summary

  • The standard search looks for terms (words or phrases) in Title, Primary sponsor, Health Condition(s), Intervention(s), Countries of recruitment, Main ID, Secondary ID(s)
  • The standard search is sensitive, finding as many records as possible
  • The standard search is not case-sensitive
  • Search results are ordered by date of registration
  • Use the asterisk (*) as a wild card for truncation (bacter* finds words such as bacterial, bacteraemia, bacteriological)
  • A phrase is two or more words in succession enclosed in double quotes. Two or more words not enclosed in double quotes will be searched for with Boolean AND. For example, liver cancer (not in quotes) will find all records containing the words liver AND cancer anywhere in the field being searched, while searching for “liver cancer” (in quotes) will return records only where the word liver is followed by the word cancer
  • Combine term searches using Boolean operators:
    • OR: find any of the terms
    • AND: find all the terms
    • NOT: find the first term without the second term

 

Additional features

  • It is also possible to filter the search by: clinical trials in children, Phases, results available

Notes and changes to previous version

  • Truncation disables synonym searching
  • Do not use truncation in the middle of a word e.g. bacte*mia will not return any hits
  • Individual words within phrases may be truncated e.g. “liv* canc*” 
  • The minimum number of characters before the asterisk is 3 e.g. li* will not return any results
  • Use parentheses when mixing Boolean operators. Parentheses may be nested to any level e.g. ((“liv* cancer*” and neoplasms) or (“Incision of liver” not malignant)) and hospital
  • The standard search is sensitive, finding as many relevant records as possible. For a more targeted (specific) search you may want to use the Advanced Search.
  • Sorting results: The default order of search results is by descending date of registration.
  • Synonyms: The standard search looks for trial records containing synonyms of search words using the UMLS metathesaurus
  • Phrases: A phrase is two or more words in succession enclosed in double quotes. Two or more words not enclosed in double quotes will be searched for with Boolean AND. For example, liver cancer (not in quotes) will find all records containing the words liver AND cancer anywhere in the field being searched, while searching for “liver cancer” (in quotes) will return records only where the word liver is followed by the word cancer
  • Truncation: Note: Truncation disables synonym searching! This means it may reduce search sensitivity. For example, a search for “liver cance*” may result in fewer hits than a search for “liver cancer” which also searches for synonyms.

 

 

Advanced Search

The advanced search looks for the presence of words or phrases in specific sections of trial records such as the Title, the Condition or Intervention being studied, etc.

Search terms

  • Use one or more of the text boxes to enter search terms. Blank text boxes are ignored.
  • Enter a full word (for example infection) or part of a word followed by an asterisk
  • It is also possible enter phrases such as "Hodgkin's lymphoma".
  • The search is not case-sensitive; a search for hiv/aids gives identical results to a search for HIV/AIDS.
  • The search is sensitive to punctuation; a search for anti-depressants gives different results to a search for antidepressants. If in doubt, search for both terms using OR: anti-depressants OR antidepressants.

Combining search terms

Multiple search terms can be combined within a field when searching on title, conditions and interventions as follows:

  • OR: finds records where any of the terms are present. For example "liver cancer" OR "breast cancer"
  • AND: finds records where all of the terms are present. For example transplant AND immunosuppressant
  • NOT: finds records where the first term is present and the second term is not present. For example Diphtheria NOT tetanus

Any number of terms can be combined. However, some combinations of AND, OR and NOT can lead to ambiguity. Care must be taken when constructing complex searches and parentheses (brackets) should be used to determine the order in which terms are combined.

Synonyms: The advanced search automatically looks for trial records containing synonyms of search words or phrases. Synonyms are generated using the UMLS metathesaurus

Sorting results: The default for displaying search results is by date of registration in descending order.

Description of search fields on the advanced search page

For more information on any field please refer to the Trial Registration Data Set

  • Title: Trials can have 2 types of title: a public title which should use plain language, and a scientific title which uses more technical language. Trials can also have an acronym. A search of the "Title" field searches both public and scientific titles, and acronyms. Multiple terms can be combined using AND, OR, NOT.
  • Condition: Health condition(s) or problem(s) studied. These often refer to an illness, disorder or injury, such as: asthma, learning disorders or bone fractures, but can also include any health issue such as pregnancy, mobility, education etc. Records contain free text and/or controlled vocabulary (such as MeSH). Searches automatically include synonyms generated using the UMLS metathesaurus. Multiple terms can be combined using AND, OR, NOT.
  • Intervention: The treatment(s) or action(s) being studied and compared. These often refer to medicines, procedures or devices, but can also include actions such as educational programmes. Records contain free text and/or controlled vocabulary. Searches automatically include synonyms generated using the UMLS metathesaurus. Multiple terms can be combined using AND, OR, NOT.
  • Clinical trials in children: The box can be clicked to search for clinical trials in children.
  • Recruitment status: Whether or not a trial is currently accepting new participants. This is known as 'recruitment' or 'enrolment'
  • Primary sponsor: The individual, organization or company responsible for initiating, managing and/or financing a trial. The Primary Sponsor may or may not be the main funder.
  • Secondary ID: Trial identifying numbers issued by other agencies, such as protocol numbers, funding agency numbers and identifiers issued by other trial registries.
  • Countries of recruitment: Countries and/or territories from which participants will be, are intended to be, or have been recruited.
  • Date of registration: The date when a trial was officially registered and trial details published in the register. The period of the search can be chosen.
  • Phases: Several phases can be selected for the search.
  • Results: To search for studies with results, click on the filter “with results only”. After entering your search term, activate the filter, in order to quickly identify trials with results. This function can be used as well in the standard as in the advanced search.

 

 

List By

  • List by Health Topics: This function allows to list the trials by the current health topics provided by WHO. It is updated weekly and shows the last date of update. This filter searches in the ‘title’ or ‘condition’ fields and returns all trial records concerning this health topic.
  • List by Countries: This function allows to list all trials by countries of recruitment.
  • List by Regions/Countries: This function shows the distribution of the trials into the different WHO regions and countries of recruitment.

 

 

UTN (Universal Trial Number)

How to obtain a UTN?

Go to  https://trialsearch.who.int/utn.aspx and follow the instructions.

The process of obtaining a UTN involves 2 stages:

  • applying for and obtaining a security code
  • applying for and obtaining the UTN

To apply for the security code, the applicant will need to provide:

  • the name of the individual submitting the request (Requestor)
  • the email address of the individual submitting the request
  • the Requestor's organization

An email containing a secure hyperlink will then be sent to the email address entered. You should click on the hyperlink which will take you to the 'Get UTN' web site, where you should click on 'Get UTN'. The UTN will then be sent to you in an email.