Background
PICO Searching
A&I databases such as Ovid MEDLINE lend themselves well to targeted searching of scientific literature. This is because they are composed of very granular units of information in the form of database FIELDS. And are usually indexed using a controlled vocabulary, also referred to as a thesaurus. Ovid MEDLINE uses the MeSH thesaurus.
Where a medical intervention is being assessed, a commonly used format for structured searching is the PICO approach. Here, P stands for population or patient group, I for intervention, C for a comparator and O for outcome or outcomes. This format has gained prominence in the assessment of the efficacy of drug-based interventions. When searching on each of these four components, i.e. Population, Intervention, Comparator and Outcomes, it is recommended practice that the searcher conducts a thesaurus search supplemented by a free term search for each one.
Populations, the first component of PICO searching, presents its own issues and challenges. Groups of people are inherently diverse. They may be differently or even contentiously labelled. This has the consequence that they may be difficult to locate and identify within the scientific literature. In some cases even to the extent of remaining ‘invisible’.
The Population ‘Children’
This Focused Search addresses the population ‘children’ and does so broadly covering human females and males from neonates to about 18 years of age. The Ovid search filter being made available here is based upon the “Improved Cochrane Childhood Cancer Group" (CCG) child filter for PubMed as developed by Leclercq et al 2013 (see References below). The original search filter, constructed for execution in PubMed, has been validated and in terms of performance, offers a significant improvement upon previous such searches. That said, its rendering for use in Ovid MEDLINE has involved numerous syntactical compromises, that in this instance we prefer to classify the Ovid MEDLINE version as a search filter rather than a validated search filter.
The Original PubMed Search
The original validated and improved CCG child filter for PubMed is as given below.
Infan* OR newborn* OR new-born* OR perinat* OR neonat* OR baby OR baby* OR babies OR toddler* OR minors OR minors* OR boy OR boys OR boyfriend OR boyhood OR girl* OR kid OR kids OR child OR child* OR children* OR schoolchild* OR schoolchild OR school child[tiab] OR school child*[tiab] OR adolescen* OR juvenil* OR youth* OR teen* OR under*age* OR pubescen* OR pediatrics[mh] OR pediatric* OR paediatric* OR peadiatric* OR school [tiab] OR school*[tiab] OR prematur* OR preterm*
The Search Filter Amended for Use on Ovid
The version of this filter rendered for use on Ovid is given below.
exp adolescent/ or exp child/ or exp infant/ or (infant disease* or childhood disease*).ti,ab,kf. or (adolescen* or babies or baby or boy? or boyfriend or boyhood or child* or girl? or infant* or juvenil* or kid? or minors or minors* or neonat* or neonat* or newborn* or new-born* or paediatric* or peadiatric* or pediatric* or perinat* or preschool* or puber* or pubescen* or school* or teen* or toddler? or underage? or under-age? or youth*).ti,ab,kf,hw.
It can be run directly in Ovid by using the jumpstart link as given < here >. This version of the search filter was last reviewed on 13th February 2023 and as mentioned, draws upon – but is not an exact reproduction of - the “Improved Cochrane Childhood Cancer Group" (CCG) child filter published here: https://doi.org/10.1016/j.jpeds.2012.09.012.
On Ovid we are also able to provide a focused version of the search filter which has the database narrow the search down to major terms as listed in the MeSH thesaurus. These are displayed in Ovid by an asterisk (*) preceding the MeSH term as shown in this particular version of the search below.
exp *adolescent/ or exp *child/ or exp *infant/ or (infant disease* or childhood disease*).ti,kf. or (adolescen* or babies or baby or boy? or boyfriend or boyhood or child* or girl? or infant* or juvenil* or kid? or minors or minors* or neonat* or neonat* or newborn* or new-born* or paediatric* or peadiatric* or pediatric* or perinat* or preschool* or puber* or pubescen* or school* or teen* or toddler? or underage? or under-age? or youth*).ti,kf.
This version of the search filter can be run directly in Ovid by using the jumpstart link as given < here >. Also reviewed lastly on 13th February 2023, this filter not only employs focused, i.e.*MeSH Term, subject headings but also only uses the database fields Title (TI) and Keywords (KF) for the free-text component of the strategy.
The Search Filter on Ovid
The two ways in which these search filters can be use on Ovid are shown below.
Line #1 employs the docz.dz command which displays all the records in the database at the time the command is executed. This serves as an example search upon which the Ovid Children Search Filter can be applied, see line #2. The ‘limit’ version of the search does not display the terms and phrases that made up the filter. However, where the same search is run, either from this Focused Search or from its listing in the Database Field Guide, the terms and phrases are show and can be verified or altered. See line #3.
Lines #4, #5 and #6 provides the same information for the Ovid Children Search Filter – Focused version of the search filter.
To run the above search in Ovid MEDLINE, click < here >.
(*) Editor's Note: This is an updated, or in some cases, a completely revised version of a search filter formerly available on the Ovid Tools & Resources Portal. All such search filters are marked with the asterisk character placed at the end of the long title. If you have any questions relating to the migration of this search filter between the two portals, please contact us directly via [email protected] .
Search Stategy
exp adolescent/ or exp child/ or exp infant/ or (infant disease* or childhood disease*).ti,ab,kf. or (adolescen* or babies or baby or boy? or boyfriend or boyhood or child* or girl? or infant* or juvenil* or kid? or minors or minors* or neonat* or neonat* or newborn* or new-born* or paediatric* or peadiatric* or pediatric* or perinat* or preschool* or puber* or pubescen* or school* or teen* or toddler? or underage? or under-age? or youth*).ti,ab,kf,hw.
Reviewers
Primary: Michael Fanning
Secondary: Charlotte Viken
Review Date: 2025-05-19
Expiry Date: 2026-05-19
Original search produced by:
Ovid Training Team
References:
Leclercq E, Leeflang MM, van Dalen EC, Kremer LC. Validation of search filters for identifying pediatric studies in PubMed. The Journal of pediatrics. 2013 Mar 1;162(3):629-34.
OvidGO! / Skills Videos
What are Boolean Operators?
What is an adjacency operator?
What are wildcards?
Subject heading searching
Truncation of keywords
Phrase searching on Ovid
Citation:
OvidGO! Portal. Focused Searches: Population Localisation: Children - Ovid MEDLINE [Internet]. London (UK): Ovid Training Team (Editors); 2025 [updated 18 June 2025; cited 20 June 2025]. Available from: https://tools.ovid.com/ovidgo/searches/view.php?id=130