Building and Documenting a Database Search
Finding & Synthesizing Health Evidence
Learning objectives for this lesson:
- Turn a review question into a concept table that lists subject headings and free-text synonyms for each search concept.
- Explain why review searches combine subject headings with free-text terms, and use explosion and scope notes when choosing headings.
- Combine search terms with Boolean operators and parentheses, and explain why NOT can remove relevant records.
- Apply truncation, wildcards, phrase searching, proximity operators and field tags in Ovid syntax.
- Write a complete MEDLINE search strategy in Ovid syntax in numbered lines, and check it against a test set of known studies.
- Translate a MEDLINE strategy into CINAHL (EBSCOhost), Embase, APA PsycInfo and Web of Science, adjusting the vocabulary and syntax for each database and platform.
- Decide whether a validated search filter suits a review, and justify any limits applied to a search.
- Peer review a search strategy with the six elements of the PRESS 2015 guideline, and report a database search according to PRISMA-S.
- Describe how a database search for a review question is built, tested, peer reviewed and logged.
This course was developed by Dr. Kiffer G. Card, Faculty of Health Sciences, Simon Fraser University, drawing on the Cochrane Handbook for Systematic Reviews of Interventions and the JBI Manual for Evidence Synthesis.
Concept Tables, Synonyms and Controlled Vocabulary
Learning Objectives for this section
- Identify which elements of a review question become search concepts, and explain why most review searches combine two to four concepts.
- Build a concept table that lists subject headings and free-text synonyms for each concept.
- Use known relevant studies, thesaurus entry terms, published search strategies and interest holders as sources of synonyms and spelling variants.
- Explain how explosion, major-topic restriction and indexing delays affect what a subject heading search retrieves.
- Check a draft search against a test set of known relevant studies.
Introduction
A database search for a systematic or scoping review is part of the review's method, in the same way that a sampling plan is part of a survey. Another team should be able to read the search, judge whether it was likely to find the relevant studies, and run it again. Lesson 3 explained how bibliographic databases index records and return every record that matches a Boolean query. This lesson follows the evidence team of the fictional Cedar Valley Health Authority as its librarian and student intern build, translate, peer review and document the database search for their rapid scoping review.
The Cedar Valley Health Authority is a fictional health authority in British Columbia that serves about 210,000 residents, of whom about 46,000 are aged 65 and older. Its planning team is preparing to launch a community connector (social prescribing) program and has asked a small evidence team, made up of an evidence officer, a university librarian and a student intern, for a rapid scoping review and environmental scan within twelve weeks.
The review question, written in Lesson 2 with the PCC framework (Population, Concept, Context), asks which community-based interventions have been evaluated for reducing loneliness or social isolation among adults aged 65 and older, and with what outcomes. The protocol sets the context as community settings in high-income countries and makes reports published from January 2010 onward eligible. In this lesson the intern drafts the search with the librarian, and the team plans to run it in MEDLINE, Embase, CINAHL, APA PsycInfo and Web of Science.
1.1 From Review Question to Search Concepts
A search concept is one idea from the review question that a relevant record must address, expressed as a group of interchangeable terms. The first decision in building a search is which parts of the question become concepts. Each concept is later joined to the others with the Boolean operator AND, so a record is retrieved only if it contains at least one term from every concept. Every concept that is added therefore removes records, including some relevant ones whose titles and abstracts happen to describe that idea in words the search does not include. For this reason most review searches combine two to four concepts, and the remaining parts of the question are applied by reviewers during screening.
A useful test for each element of the question is to ask whether the authors of a relevant study would almost always describe it in the title, abstract or subject headings. The population and the main problem or intervention usually pass this test. Elements that authors describe inconsistently, or leave out of the abstract, usually fail it. Study design is a common example in scoping reviews, because a scoping review includes many designs and their labels vary. Setting is another, because a paper about a seniors' centre program may never use the word community.
The Cedar Valley team applied this test to the PCC question. The population (adults aged 65 and older) and the outcome or problem (loneliness or social isolation) are described in nearly every relevant abstract, so both became concepts. The concept element (community-based interventions) is more loosely described, but without it the search would retrieve thousands of studies that measure loneliness without testing any intervention, so it became a third concept with a deliberately wide set of terms. The context element (community settings in high-income countries) is judged at screening, and the date criterion is applied as a limit at the end of the search. The team decided against adding words such as evaluation or effect as a fourth concept, because many evaluations describe themselves only by their design or measures, and those records would be lost.
1.2 The Concept Table
A concept table is a grid that lists, for each search concept, the subject headings and the free-text terms that will be searched, with notes on decisions. It makes the logic of the search visible before any syntax is written, gives a peer reviewer something to check, and becomes the starting point for translation into other databases, where the headings change and the free-text terms usually stay the same (Section 3).
Two kinds of terms appear in each row. Subject headings are terms from a database's controlled vocabulary, the fixed list of headings that indexers assign to records to describe what they are about; in MEDLINE this vocabulary is MeSH (Medical Subject Headings). Free-text terms, sometimes called keywords or text words, are words searched in the title, abstract and author keyword fields, so they find records whatever headings were assigned. The table below is the Cedar Valley concept table for MEDLINE.
| Concept | MeSH headings (MEDLINE) | Free-text terms | Notes on decisions |
|---|---|---|---|
| A. Loneliness or social isolation (problem and outcome) | Loneliness; Social Isolation | lonely, loneliness, lonelier; social isolation, socially isolated, emotional isolation, social disconnection, social exclusion, social withdrawal; isolated seniors, isolated older people; social connection, social connectedness | The word isolation on its own also describes laboratory and infection-control isolation, so it is searched only near words for social life or for people. |
| B. Older adults (population) | Aged, exploded so that it includes Aged, 80 and over and Frail Elderly | older adults, older people, older persons, older individuals, older men, older women, older residents, older patients; elderly, elders, seniors, geriatric, gerontological; octogenarians, nonagenarians, centenarians; old age, later life, late life; retired, retirees, retirement | The word aged is left out as a free-text term because abstracts use it to report the ages of every group (for example, children aged 5 to 12). |
| C. Community-based interventions (concept) | Social Support; Social Participation; Community Networks; Volunteers; Peer Group; Intergenerational Relations | social prescribing, socially prescribed; community connector, neighbourhood connector, link worker, care navigator, community navigator; befriending, friendly visiting; peer support, volunteer visiting, lay mentoring, companionship; intergenerational programs and activities; social, leisure, arts, exercise, walking, gardening, music and singing groups, clubs and classes; community interventions, programs, services and initiatives | Programs of this kind carry different names in different countries: community connector is used in parts of Canada, and link worker is the usual term in the United Kingdom. |
| Not searched as concepts | None | None | Community setting and high-income country are judged at screening. Publication from 2010 onward is applied as a date limit. Study design is left open because a scoping review charts all evaluation designs. |
Concept C deliberately mixes headings for the mechanism of an intervention (social support) with headings for who delivers it (volunteers, peers), because the team cannot predict how each study will be indexed and relies on the AND with concepts A and B to remove irrelevant records. The free-text column lists word forms, which the syntax in Section 2 compresses, for example by searching lonel$ to find lonely, loneliness and lonelier.
1.3 Finding Synonyms and Variants
Most of the work of a concept table lies in the free-text column. A synonym that is missing from the table is a group of relevant records the search cannot find, and nothing in the results will reveal the gap. The JBI approach to scoping review searches begins for this reason with a limited search of at least two databases, followed by analysis of the words in the titles and abstracts of relevant records and of the index terms used to describe them, before the full search is built and run across all databases (Peters et al., 2020). The cards below describe the main sources of terms.
Older terms raise a point about language. A review team may decide, for good reasons, to write about older adults rather than the elderly. The search must still include elderly, because a large share of the literature on this population used that word, and the search has to find the literature as it was written.
Ambiguous terms raise a different point. Isolation and connector both have other meanings that would flood the results with irrelevant records. The usual solution is to keep the term and tie it to a context word with a proximity operator, which Section 2 explains.
1.4 Controlled Vocabulary in Practice
Lesson 3 explained why controlled vocabularies exist: they gather records about the same topic under one heading, whatever words the authors used. In practice, a subject heading search behaves in ways that a searcher must understand before using it. The items below describe the features that matter most when building a review search in MEDLINE, and the same ideas apply to Emtree in Embase, CINAHL Subject Headings and the APA Thesaurus of Psychological Index Terms.
MeSH headings are arranged in hierarchies called trees, with broader headings above narrower ones. To explode a heading is to search it together with every heading beneath it in the tree. In MEDLINE, the heading Aged has two narrower headings, Aged, 80 and over and Frail Elderly. The Ovid line exp Aged/ retrieves records indexed with any of the three, whereas Aged/ retrieves only records indexed with Aged itself. Reviews usually explode headings that have narrower terms, unless the narrower terms are clearly outside the question.
Each MeSH record includes a scope note that defines the heading. The scope note for Aged describes a person 65 years of age or older and points to Aged, 80 and over for people older than 79, which matches the Cedar Valley population. The record also lists entry terms, the synonyms that lead a searcher to the heading, and the year the heading was introduced.
Indexers mark a few headings on each record as its major topics. In Ovid, an asterisk before a heading (*Loneliness/) restricts the search to records where loneliness is a major topic. This raises precision, the proportion of retrieved records that are relevant, but it lowers recall, the proportion of relevant records that are retrieved. Because reviews favour recall (Lesson 3), review searches rarely use major-topic restriction.
Subject headings are assigned some time after a record enters the database, and some records are never indexed. Recent records, and records from journals that are not fully indexed, can therefore be found only with free text. New concepts raise the same problem from the other side. Thesauri are revised every year, so the librarian checks the current MeSH browser for a heading that matches social prescribing. Whether or not one exists, the search keeps free-text terms for it, because older records describe the same activity in other words and were indexed under other headings.
These features explain the standard rule for review searches: each concept is searched with both subject headings and free text, combined with OR. Headings find records that describe the concept in unexpected words, and free text finds records that are unindexed or indexed under unexpected headings.
Finding a heading in Ovid
When the option to map terms to subject headings is switched on, Ovid suggests the headings most often assigned to records containing a typed word, with the tree and scope note for each. The suggestions still need checking against the scope notes, and the strategy should list the chosen headings explicitly.
1.5 Testing the Draft with Known Studies
A test set (also called a validation set or benchmark set) is a group of studies the team already knows to be relevant, gathered from a preliminary search, from existing reviews or from experts. Once a draft strategy is written, the librarian checks how many of the test-set studies it retrieves in each database where they are indexed. A study that is indexed in the database but missed by the strategy reveals a gap: a synonym that is missing, a heading that was not used, or a concept that is too narrow.
The Cedar Valley team assembled a test set of ten evaluations of community programs for lonely or isolated older adults. Nine of them were indexed in MEDLINE, and the first draft of the MEDLINE strategy retrieved eight. The missing study described its outcome only as social connectedness and was indexed under headings that the draft did not include. The intern added a line for social connection and connectedness to concept A, and the revised strategy retrieved all nine. The team also checked whether concept C was costing recall by running concepts A and B alone. That search also retrieved all nine studies, together with many more records that measured loneliness without testing an intervention, so the team kept concept C.
A test set shows whether the search finds studies like those the team already knows, and it cannot show that the search finds studies described in ways nobody anticipated. Studies used to choose the terms will be retrieved almost by construction, so a test set is more informative when some of its studies were set aside before the terms were chosen. It is one check among several, alongside the peer review in Section 4.
A colleague proposes these free-text terms for concept B: aged, elderly, seniors, old and retirement. For each term, decide whether to keep it, drop it or restrict it, and give a reason. A strong answer drops aged and old as single words because abstracts use them to describe participants of every age, keeps elderly and seniors, keeps retirement as a term that is useful in combination with concepts A and C, and replaces old with phrases such as old age and older adults.
Reflection
A review team asks the following question: Which peer support programs have been evaluated for reducing loneliness among family caregivers of people living with dementia? The team will search MEDLINE, whose controlled vocabulary is MeSH (Medical Subject Headings). Each search concept is a group of interchangeable terms, and concepts are joined with AND, so every added concept removes records. Identify the concepts you would search and any part of the question you would apply at screening instead, and explain your choice. For each search concept, propose at least one MeSH heading and at least four free-text synonyms or spelling variants. Finally, explain whether words such as evaluated or effectiveness should become a search concept.
I would search three concepts: family caregivers, dementia and peer support. For caregivers, the heading Caregivers and the free-text terms caregiver, carer, care giver, family member and spouse would cover the population, with truncation for plurals. For dementia, the exploded heading Dementia and the terms dementia, Alzheimer, cognitive impairment and memory loss would find the condition. For peer support, the headings Peer Group, Social Support and Self-Help Groups and the terms peer support, support group, mutual aid, self-help group and peer mentor would describe the intervention.
Loneliness is the outcome of interest, but it is often a secondary outcome that appears only in the full text, so I would first apply it at screening and check whether the three-concept search returns a manageable number of records. If it does not, I would add loneliness (the heading Loneliness, plus lonely, loneliness and social isolation) as a fourth concept after checking a test set of known studies. Words such as evaluated or effectiveness should not become a concept, because many evaluations describe themselves only by their design or measures and would be lost. Design and outcome are better judged with the eligibility criteria.
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Question 1: The Cedar Valley review question has a population, a concept, a context (community settings in high-income countries) and a date criterion. Why did the team search the population, the problem and the intervention as concepts but apply the context at screening?
Question 2: Why does a review search combine subject headings with free-text terms for each concept?
Question 3: In MEDLINE, the heading Aged has two narrower headings, Aged, 80 and over and Frail Elderly. What does the Ovid line exp Aged/ retrieve?
exp Aged/ retrieves records indexed with any of the three. Major-topic restriction uses an asterisk, and a free-text search of the word would need a field tag such as .ti,ab,kf..Question 4: The first Cedar Valley draft retrieved eight of the nine test-set studies indexed in MEDLINE. What is the most appropriate next step?
Boolean Operators, Truncation, Phrases, Proximity and Field Tags
Learning Objectives for this section
- Combine terms within a concept with OR and between concepts with AND, and explain why NOT can remove relevant records.
- Use parentheses and numbered search lines so that a database processes a search in the intended order.
- Apply truncation and wildcards in Ovid syntax and recognize stems that are too short.
- Use phrase searching and adjacency operators to search ideas that span several words.
- Restrict terms to fields with field tags, and read a complete Ovid MEDLINE strategy line by line.
Introduction
The concept table in Section 1 lists what to search. This section turns it into a working search in Ovid, the platform the Cedar Valley librarian uses for MEDLINE. Ovid keeps a numbered search history in which each line can be a set of terms or a combination of earlier lines, and its syntax uses a small set of symbols and operators. The section explains each element and then presents the full strategy. Section 3 shows how the same strategy is written for other databases and platforms.
2.1 Boolean Operators
Boolean operators tell the database how to combine sets of records. OR retrieves records that contain any of the terms it joins, so it widens a search and is used inside a concept. AND retrieves records that contain at least one term from each set it joins, so it narrows a search and is used between concepts. NOT removes every record in the second set from the first, so it narrows a search by exclusion.
| Operator | What it retrieves | Cedar Valley example |
|---|---|---|
| OR | Records containing any of the terms | Loneliness/ or lonel$.ti,ab,kf. finds records indexed with the heading or using the words. |
| AND | Records containing at least one term from every set | 7 and 12 and 26 keeps records that address loneliness or isolation, older adults and community interventions. |
| NOT | Records in the first set that are absent from the second | exp animals/ not humans/ identifies records indexed only as animal studies. |
NOT needs care, because it removes a record if the excluded term appears anywhere in the searched fields, even when the record is relevant. Suppose the intern wanted to remove studies of children and added not child$.ti,ab. to the search. The line would remove every intergenerational program in which older adults spend time with children, which are among the interventions the review is looking for. The animal-studies line in the table is a safer use of NOT. It first finds records indexed with animal headings that are not also indexed with the heading Humans, and only those records are removed, so a study that involves both people and animals stays in the results. This form of the line is widely used and appears in Cochrane guidance on searching (Lefebvre et al., 2023).
Parentheses and numbered lines
When a single line mixes operators, the database applies its own order of precedence, and that order differs between platforms. The line lonely or isolated and seniors could be read as lonely or (isolated and seniors), which retrieves every record about loneliness at any age, or as (lonely or isolated) and seniors, which is what the searcher intended. Parentheses remove the ambiguity: (lonely or isolated) and seniors. Any line that mixes operators should use them.
Review searches go further and build the strategy in numbered lines, usually one line per subject heading or per group of related free-text terms, followed by a line that combines each concept with OR and a final line that combines the concepts with AND. In Ovid, or/1-6 combines lines 1 to 6 with OR. Numbered lines make errors easier to find, show how many records each line contributes, and let a peer reviewer check every combination. This layout is often called the building-block approach.
2.2 Truncation and Wildcards
Truncation searches every word that begins with a given stem. In Ovid, the dollar sign ($) and the asterisk (*) both act as unlimited truncation, and this lesson uses the dollar sign in Ovid strategies. volunteer$ finds volunteer, volunteers, volunteered and volunteering. A number after the symbol limits the number of extra characters, so club$1 finds club and clubs and stops there.
A wildcard stands for a character inside a word. In Ovid, # stands for exactly one character (wom#n finds woman and women), and ? stands for one character or none (behavio?r finds behavior and behaviour, and neighbo?rhood finds both spellings of neighbourhood). Section 3 shows that other platforms assign different meanings to these symbols, which is a common source of translation errors.
The main risk with truncation is a stem that is too short. The table lists examples the Cedar Valley team considered and rejected.
| Truncated term | Intended words | Unwanted words it also finds | Solution |
|---|---|---|---|
art$ | art, arts | artery, arterial, arthritis, article, artificial | Search art or arts |
class$ | class, classes | classification, classic, classified | Search class or classes |
old$ | older, oldest | old in phrases such as five-year-old children | Search phrases such as old age and older adj3 adult$ |
communit$ | community, communities | Few unwanted words, but very many records | Keep, and tie it to intervention words with adjacency |
2.3 Phrase Searching
A phrase search retrieves words only when they appear next to each other in the order given. Ovid treats words typed side by side as a phrase, so later life.ti,ab. searches the phrase later life. Quotation marks are optional in Ovid and are needed mainly when a phrase contains a word Ovid would otherwise read as an operator, such as and or or. Truncation can be used inside a phrase, so friendly visit$ finds friendly visit, friendly visits and friendly visiting. Phrases are precise, but they miss the same idea expressed with the words in another order or separated by other words. Social isolation as a phrase misses isolated socially and social and emotional isolation. Proximity operators address that problem.
2.4 Proximity Operators
A proximity operator retrieves two terms when they appear within a set distance of each other. In Ovid, adj on its own finds terms next to each other in the order typed, and adj followed by a number finds terms within that many words of each other in either order. The number counts the words themselves, so adj3 allows up to two words in between and adj2 allows one. Figure 2 shows how line 4 of the Cedar Valley strategy treats four phrases.
The distance is a judgement about recall and precision. A small number behaves almost like a phrase. A large number finds more variants but also pairs words that belong to different ideas, such as social at the end of one clause and isolation at the start of the next. Distances of two to five words are common in review searches, and the choice should be tested by looking at a sample of the records each setting adds. Proximity also offers a more precise alternative to AND inside a line: (intergeneration$ adj3 program$) requires the two words to be close together, whereas intergeneration$ and program$ retrieves any record that uses both words anywhere.
2.5 Field Tags
A field tag restricts a term to one or more parts of the record. In Ovid, field tags follow the term, between full stops. Searching free-text terms in the title, abstract and author keywords is the usual choice for reviews, because these fields describe what the study is about, whereas the full record also contains author addresses, journal names and reference lists in some databases.
| Ovid syntax | What it searches | Example |
|---|---|---|
/ after a term | The term as a subject heading | Loneliness/ |
exp before a heading | The heading and all narrower headings (explode) | exp Aged/ |
.ti. and .ab. | Title; abstract | lonel$.ti. |
.kf. | Author keywords in Ovid MEDLINE (Ovid calls this the keyword heading word field) | befriend$.kf. |
.ti,ab,kf. | Title, abstract and author keywords together | (befriend$ or friendly visit$).ti,ab,kf. |
.tw. | Text word, a combined field that each Ovid database defines in its own way | lonel$.tw. |
.mp. | A database-specific bundle of fields that includes the title, abstract and subject heading words; Ovid applies it when a term is typed without a field tag | lonel$.mp. |
.pt. | Publication type | editorial.pt. |
Because .tw. and .mp. cover different fields in different databases, the Cedar Valley librarian lists the fields explicitly with .ti,ab,kf.. Explicit tags make the strategy easier to report, easier to peer review and easier to translate, since the translator can see exactly which fields each line searched.
2.6 The Full MEDLINE Strategy
The strategy below is the final Cedar Valley MEDLINE search, after the test-set check in Section 1 and the peer review described in Section 4. It is shown as it would be exported from Ovid, which is the form required for reporting. The search date and record count belong to the fictional project.
Database: Ovid MEDLINE(R) ALL <1946 to February 09, 2026> Date searched: 10 February 2026 ------------------------------ 1 Loneliness/ 2 Social Isolation/ 3 lonel$.ti,ab,kf. 4 ((social$ or emotional$) adj3 (isolat$ or disconnect$ or exclu$ or withdraw$)).ti,ab,kf. 5 ((isolated or isolation) adj3 (older or elder$ or senior$ or people or person$)).ti,ab,kf. 6 (social$ adj2 connect$).ti,ab,kf. 7 or/1-6 8 exp Aged/ 9 (older adj3 (adult$ or people or person$ or individual$ or men or women or resident$ or population$ or patient$)).ti,ab,kf. 10 (elder$ or senior$ or geriatric$ or gerontolog$ or octogenarian$ or nonagenarian$ or centenarian$).ti,ab,kf. 11 (old age or later life or late life or retire$).ti,ab,kf. 12 or/8-11 13 Social Support/ 14 Social Participation/ 15 Community Networks/ 16 Volunteers/ 17 Peer Group/ 18 Intergenerational Relations/ 19 (social$ adj2 prescri$).ti,ab,kf. 20 ((community or link or neighbo?rhood or care) adj2 (connector$ or navigator$ or worker$)).ti,ab,kf. 21 (befriend$ or friendly visit$).ti,ab,kf. 22 ((peer or volunteer$ or lay) adj3 (support$ or visit$ or mentor$ or companion$)).ti,ab,kf. 23 (intergeneration$ adj3 (program$ or activit$ or project$ or contact$)).ti,ab,kf. 24 ((group or groups or club or clubs or class or classes) adj3 (social$ or leisure or recreation$ or art or arts or exercis$ or walking or garden$ or music or singing or choir$)).ti,ab,kf. 25 (communit$ adj3 (intervention$ or program$ or service$ or initiative$)).ti,ab,kf. 26 or/13-25 27 7 and 12 and 26 28 exp animals/ not humans/ 29 27 not 28 30 limit 29 to yr="2010 -Current"
Line 30 retrieved 742 records in the fictional search. A real export also lists the number of records for every line, and those counts are useful in peer review because a line that retrieves nothing, or an implausibly large number, often signals an error.
Lines 1 and 2 are the two MeSH headings. Line 3 uses truncation to find every form of lonely. Line 4 uses adjacency to find social or emotional isolation, disconnection, exclusion and withdrawal in any word order. Line 5 searches isolated or isolation only near words for people, which avoids laboratory uses of the word. Line 6 was added after the test-set check to capture social connection and social connectedness. Line 7 combines lines 1 to 6 with OR.
Line 8 explodes Aged so that Aged, 80 and over and Frail Elderly are included. Line 9 uses adjacency so that older adults, older Canadian adults and adults who are older are all found. Lines 10 and 11 add single words and phrases. The word aged is absent from the free-text lines for the reason given in the concept table. Line 12 combines the block.
Lines 13 to 18 are the six MeSH headings from the concept table. Line 19 finds social prescribing and socially prescribed. Line 20 ties ambiguous words such as connector and worker to context words, and uses the optional wildcard to find both spellings of neighbourhood. Lines 21 to 25 search befriending, peer and volunteer support, intergenerational programs, group activities and community programs. The group-activity line searches art or arts and class or classes to avoid the truncation problems shown in Section 2.2. Line 26 combines the block.
Line 27 combines the three concepts with AND. Lines 28 and 29 remove records indexed only as animal studies. Line 30 applies the protocol's date criterion with Ovid's publication year limit. No language limit is applied, because the protocol makes English and French reports eligible and asks the team to list relevant reports in other languages, which the team can do only if the search retrieves them.
Write line 22 as a plain-English sentence, then decide which of these phrases it would retrieve in a title or abstract: peer support, support from trained volunteers, lay health workers and volunteers visited participants weekly. Line 22 retrieves records in which peer, any word beginning with volunteer, or lay appears within three words, in either order, of any word beginning with support, visit, mentor or companion. The first, second and fourth phrases are retrieved. The third is missed by this line, because workers is outside the second group of terms.
Reflection
In Ovid, a slash after a term (Aged/) searches it as a subject heading, exp before a heading also searches every narrower heading, $ truncates a word, adj3 finds two terms in either order with up to two words between them, and .ti,ab. restricts terms to the title and abstract. In MEDLINE the heading Aged has two narrower headings, Aged, 80 and over and Frail Elderly. A colleague wrote these lines for a search on loneliness and social isolation among older adults: 1 Loneliness/; 2 lonly.ti,ab.; 3 Aged/; 4 (elder$ or senior$ or old$).ti,ab.; 5 1 or 2; 6 3 or 4; 7 5 or 6. Identify at least four errors or weaknesses, and write corrected lines, including one line that uses adjacency to search social isolation in any word order.
Line 2 misspells the word, so it searches lonly and misses lonely and loneliness; it should read lonel$.ti,ab.. Line 3 is not exploded, so it misses records indexed only with Aged, 80 and over or Frail Elderly; it should read exp Aged/. In line 4, old$ retrieves old in phrases such as five-year-old children, which adds many irrelevant records; it should be replaced with phrases and adjacency, for example (older adj3 (adult$ or people or person$)).ti,ab. and (old age or later life).ti,ab.. Line 7 combines the two concepts with OR, which retrieves every record about loneliness at any age and every record about older adults on any topic; it should be 5 and 6. The concept of social isolation is also missing.
A corrected strategy reads: 1 Loneliness/; 2 Social Isolation/; 3 lonel$.ti,ab.; 4 ((social$ or emotional$) adj3 isolat$).ti,ab.; 5 or/1-4; 6 exp Aged/; 7 (older adj3 (adult$ or people or person$)).ti,ab.; 8 (elder$ or senior$ or old age or later life).ti,ab.; 9 or/6-8; 10 5 and 9. Line 4 finds social isolation, isolated socially and social and emotional isolation.
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Question 1: An intern adds not child$.ti,ab. to the Cedar Valley strategy to remove studies of children. What is the main problem with this line?
Question 2: In Ovid, which phrases does (social$ adj3 isolat$) retrieve?
adj3 finds the two terms in either order with up to two words between them. It therefore retrieves the first three phrases and misses social activities reduced their isolation, which has three words between the terms. Plain adj keeps the typed order; AND ignores distance.Question 3: Why does the Cedar Valley strategy search art or arts in place of art$?
Question 4: Why did the Cedar Valley librarian use .ti,ab,kf. in place of .mp. for free-text lines?
.mp. includes titles and abstracts as well as heading words, and neither tag searches full text.Translating a Search Across Databases and Using Search Filters
Learning Objectives for this section
- Distinguish a database from the platform used to search it, and explain which parts of a strategy depend on each.
- Translate subject headings, field tags, truncation, wildcards and proximity operators from Ovid MEDLINE into CINAHL (EBSCOhost), Embase, APA PsycInfo and Web of Science.
- Check a translated strategy line by line, including headings that have no direct equivalent.
- Describe what a validated search filter is and decide whether one suits a given review.
- Justify, or avoid, limits on language, date, publication type and age.
Introduction
No single database indexes all the literature on a health question, so reviews search several, and the strategy developed in one database, the master strategy, is rewritten for each of the others. This search translation changes both the controlled vocabulary and the syntax. This section translates the Cedar Valley MEDLINE strategy and then considers search filters and limits.
3.1 Why Search Several Databases
Databases differ in the journals and record types they cover, as the cards below summarize. For Cochrane reviews of interventions, the Cochrane Handbook treats searches of the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE and Embase as the minimum, with other databases added according to the topic (Lefebvre et al., 2023).
Research on loneliness among older adults appears in gerontology, nursing, psychology, social work and public health journals, so the Cedar Valley team planned searches of all five databases below and a separate grey-literature search for program reports (Lesson 5).
3.2 Databases and Platforms
A database is a collection of records with its own coverage and, usually, its own thesaurus. A platform (sometimes called an interface or host) is the software used to search it. The same database can be searched on different platforms: MEDLINE through PubMed or Ovid, Embase through Embase.com or Ovid, and APA PsycInfo through Ovid or EBSCOhost. The controlled vocabulary belongs to the database and the syntax belongs to the platform, so translating from Ovid MEDLINE to Ovid Embase changes the headings and keeps most of the syntax, whereas translating to CINAHL on EBSCOhost changes both. The platform must also be reported, because the same strategy can retrieve different records on different platforms.
3.3 What Changes in Translation
The table compares the main syntax elements on four platforms. Each platform's help pages remain the authority, since syntax is revised over time.
| Element | Ovid (MEDLINE, Embase, APA PsycInfo) | EBSCOhost (CINAHL) | Embase.com | Web of Science |
|---|---|---|---|---|
| Subject heading | Loneliness/ | (MH "Loneliness") | 'loneliness'/de | No thesaurus |
| Exploded heading | exp Aged/ | (MH "Aged+") | 'aged'/exp | No thesaurus |
| Title and abstract | .ti,ab. | TI ... OR AB ... (separate fields) | :ti,ab | TS= (topic) |
| Author keywords | .kf. in MEDLINE, .kw. in Embase, .id. in APA PsycInfo | Searched separately if needed | :kw | Included in TS= |
| Unlimited truncation | $ or * | * | * | * |
| Exactly one character | # | ? | ? | ? |
| One character or none | ? | # | See help pages | $ |
| Proximity, any order, up to two words between | adj3 | N2 | NEAR/n; confirm counting in help pages | NEAR/2 |
| Phrase | Words typed together | "later life" | 'later life' | "later life" |
| Combining lines | or/1-6; 7 and 12 and 26 | S1 OR S2 | #1 OR #2 | #1 OR #2 |
Three kinds of difference cause most translation errors. Ovid and EBSCOhost give opposite meanings to # and ?, so a copied wildcard searches something different. In Web of Science, $ stands for one character or none, so the Ovid term lonel$ copied unchanged would miss loneliness entirely. Platforms also count proximity differently: Ovid counts the search words themselves, so adj3 allows two words between them, whereas EBSCOhost and Web of Science count only the words in between, so the equivalents are N2 and NEAR/2.
3.4 Translating the Cedar Valley Strategy
The translation proceeds line by line. For each subject heading, the librarian reads the target thesaurus's scope note and tree and chooses the closest heading, which may differ in name or scope. For each free-text line, the librarian changes the field tags, truncation, wildcards and proximity operators. The table records the heading decisions, and the tabs show the translated strategies.
| MEDLINE (MeSH) | Embase (Emtree) | CINAHL Subject Headings |
|---|---|---|
| Loneliness | loneliness | Loneliness |
| Social Isolation | social isolation | Social Isolation |
| Aged (exploded) | aged (exploded) | Aged (exploded) |
| Social Support | social support | Support, Psychosocial (exploded) |
| Volunteers | volunteer | Volunteer Workers |
| Peer Group | peer group | Peer Group |
| Intergenerational Relations | No heading chosen; free text covers the idea | Intergenerational Relations |
| Social Participation; Community Networks | No heading chosen; free text covers the idea | No heading chosen; free text covers the idea |
All three vocabularies are revised annually, so headings must be checked in each thesaurus at the time of searching. When no heading matches closely, the librarian relies on the free-text lines and records the decision.
CINAHL requires the title and abstract fields to be searched separately, so each free-text line is written twice inside one search line. Ovid adj3 becomes N2, adj2 becomes N1, $ becomes *, and the optional wildcard ? becomes #. The animal-studies line was judged unnecessary for CINAHL, and the date criterion is applied with the Published Date limiter.
Database: CINAHL (EBSCOhost) Date searched: 10 February 2026 S1 (MH "Loneliness") S2 (MH "Social Isolation") S3 TI lonel* OR AB lonel* S4 TI ( (social* OR emotional*) N2 (isolat* OR disconnect* OR exclu* OR withdraw*) ) OR AB ( (social* OR emotional*) N2 (isolat* OR disconnect* OR exclu* OR withdraw*) ) S5 TI ( (isolated OR isolation) N2 (older OR elder* OR senior* OR people OR person*) ) OR AB ( (isolated OR isolation) N2 (older OR elder* OR senior* OR people OR person*) ) S6 TI ( social* N1 connect* ) OR AB ( social* N1 connect* ) S7 S1 OR S2 OR S3 OR S4 OR S5 OR S6 S8 (MH "Aged+") S9 TI ( older N2 (adult* OR people OR person* OR individual* OR men OR women OR resident* OR population* OR patient*) ) OR AB ( older N2 (adult* OR people OR person* OR individual* OR men OR women OR resident* OR population* OR patient*) ) S10 TI ( elder* OR senior* OR geriatric* OR gerontolog* OR octogenarian* OR nonagenarian* OR centenarian* ) OR AB ( elder* OR senior* OR geriatric* OR gerontolog* OR octogenarian* OR nonagenarian* OR centenarian* ) S11 TI ( "old age" OR "later life" OR "late life" OR retire* ) OR AB ( "old age" OR "later life" OR "late life" OR retire* ) S12 S8 OR S9 OR S10 OR S11 S13 (MH "Support, Psychosocial+") S14 (MH "Volunteer Workers") S15 (MH "Peer Group") S16 (MH "Intergenerational Relations") S17 TI ( social* N1 prescri* ) OR AB ( social* N1 prescri* ) S18 TI ( (community OR link OR neighbo#rhood OR care) N1 (connector* OR navigator* OR worker*) ) OR AB ( (community OR link OR neighbo#rhood OR care) N1 (connector* OR navigator* OR worker*) ) S19 TI ( befriend* OR (friendly N1 visit*) ) OR AB ( befriend* OR (friendly N1 visit*) ) S20 TI ( (peer OR volunteer* OR lay) N2 (support* OR visit* OR mentor* OR companion*) ) OR AB ( (peer OR volunteer* OR lay) N2 (support* OR visit* OR mentor* OR companion*) ) S21 TI ( intergeneration* N2 (program* OR activit* OR project* OR contact*) ) OR AB ( intergeneration* N2 (program* OR activit* OR project* OR contact*) ) S22 TI ( (group OR groups OR club OR clubs OR class OR classes) N2 (social* OR leisure OR recreation* OR art OR arts OR exercis* OR walking OR garden* OR music OR singing OR choir*) ) OR AB ( (group OR groups OR club OR clubs OR class OR classes) N2 (social* OR leisure OR recreation* OR art OR arts OR exercis* OR walking OR garden* OR music OR singing OR choir*) ) S23 TI ( communit* N2 (intervention* OR program* OR service* OR initiative*) ) OR AB ( communit* N2 (intervention* OR program* OR service* OR initiative*) ) S24 S13 OR S14 OR S15 OR S16 OR S17 OR S18 OR S19 OR S20 OR S21 OR S22 OR S23 S25 S7 AND S12 AND S24 S26 S25 Limiters - Published Date: 20100101-20261231
The phrase friendly visit$ becomes friendly N1 visit*, because the librarian prefers proximity to truncation inside quotation marks on EBSCOhost.
On the same platform the syntax barely changes. The headings become Emtree headings, the author keyword tag becomes .kw., and the animal-studies line takes the form commonly used in Embase. Some teams remove Embase's many conference abstracts with conference abstract.pt.; the Cedar Valley protocol asks screeners to look for a full report of any relevant abstract, so the search keeps them.
Database: Embase <1974 to 2026 February 09> Date searched: 10 February 2026 1 loneliness/ 2 social isolation/ 3 lonel$.ti,ab,kw. 4 ((social$ or emotional$) adj3 (isolat$ or disconnect$ or exclu$ or withdraw$)).ti,ab,kw. 5 ((isolated or isolation) adj3 (older or elder$ or senior$ or people or person$)).ti,ab,kw. 6 (social$ adj2 connect$).ti,ab,kw. 7 or/1-6 8 exp aged/ 9 (older adj3 (adult$ or people or person$ or individual$ or men or women or resident$ or population$ or patient$)).ti,ab,kw. 10 (elder$ or senior$ or geriatric$ or gerontolog$ or octogenarian$ or nonagenarian$ or centenarian$).ti,ab,kw. 11 (old age or later life or late life or retire$).ti,ab,kw. 12 or/8-11 13 social support/ 14 volunteer/ 15 peer group/ 16 (social$ adj2 prescri$).ti,ab,kw. 17 ((community or link or neighbo?rhood or care) adj2 (connector$ or navigator$ or worker$)).ti,ab,kw. 18 (befriend$ or friendly visit$).ti,ab,kw. 19 ((peer or volunteer$ or lay) adj3 (support$ or visit$ or mentor$ or companion$)).ti,ab,kw. 20 (intergeneration$ adj3 (program$ or activit$ or project$ or contact$)).ti,ab,kw. 21 ((group or groups or club or clubs or class or classes) adj3 (social$ or leisure or recreation$ or art or arts or exercis$ or walking or garden$ or music or singing or choir$)).ti,ab,kw. 22 (communit$ adj3 (intervention$ or program$ or service$ or initiative$)).ti,ab,kw. 23 or/13-22 24 7 and 12 and 23 25 (exp animal/ or nonhuman/) not exp human/ 26 24 not 25 27 limit 26 to yr="2010 -Current"
Institutions that license Embase through Elsevier search it on Embase.com, where the syntax differs. The first concept is shown here. Emtree headings appear in single quotation marks with /de (unexploded) or /exp (exploded), and field codes follow a colon. Platforms count proximity distance in different ways, so the librarian confirms how Embase.com counts it in the platform's help pages before choosing the number, and tests the line against the Ovid version.
#1 'loneliness'/de OR 'social isolation'/de #2 lonel*:ti,ab,kw #3 ((social* OR emotional*) NEAR/3 (isolat* OR disconnect* OR exclu* OR withdraw*)):ti,ab,kw #4 ((isolated OR isolation) NEAR/3 (older OR elder* OR senior* OR people OR person*)):ti,ab,kw #5 (social* NEAR/2 connect*):ti,ab,kw #6 #1 OR #2 OR #3 OR #4 OR #5
On Ovid, APA PsycInfo uses the same operators, with headings from the APA Thesaurus and .id. for author keywords. Its first lines read as follows.
1 Loneliness/ 2 Social Isolation/ 3 lonel$.ti,ab,id. 4 ((social$ or emotional$) adj3 (isolat$ or disconnect$ or exclu$ or withdraw$)).ti,ab,id.
The age of the population studied is recorded mainly in an age group field, so concept B relies on the free-text lines, and the librarian may add the age group field as an extra line combined with OR.
Web of Science has no thesaurus, so the heading lines are dropped and each concept becomes one topic search. The Ovid $ must become *, and adj3 becomes NEAR/2. The first concept is shown here.
#1 TS=(lonel* OR ((social* OR emotional*) NEAR/2 (isolat* OR disconnect* OR exclu* OR withdraw*)) OR ((isolated OR isolation) NEAR/2 (older OR elder* OR senior* OR people OR person*)) OR (social* NEAR/1 connect*))
Translation tools and checks
The Polyglot Search Translator converts the syntax of a strategy between common platforms, and a randomized trial found that it reduced the time searchers spent on translation (Clark et al., 2020). Such tools leave the choice of headings to the searcher, so every translated heading still has to be checked. After translation, the librarian runs each line, compares its record count with the corresponding MEDLINE line, investigates any line that retrieves nothing or far more than expected, and repeats the test-set check in each database.
3.5 Validated Search Filters
A search filter (also called a hedge) is a ready-made block of search lines that retrieves a type of record, most often a study design such as randomized controlled trials, and sometimes an age group or geographic area. A validated filter has been tested against a reference set of records of known status, so its sensitivity (the share of relevant records it retrieves) and precision are reported, often in versions that favour one or the other. A filter is designed for one database and platform, and it should be used as published, cited and, if modified, described as modified.
The Cochrane Highly Sensitive Search Strategy for identifying randomized trials in MEDLINE is published in Ovid and PubMed formats in the Cochrane guidance on searching (Lefebvre et al., 2023). The Hedges project at McMaster University tested filters for studies of treatment and other categories (Haynes et al., 2005). The InterTASC Information Specialists' Sub-Group (ISSG) Search Filter Resource is a directory of published filters.
A design filter suits a review limited to one design, such as randomized trials. The Cedar Valley scoping review charts every kind of evaluation, from trials to before-and-after studies, and a trial filter would remove most of the records it needs, so the team used no design filter.
3.6 Limits
A limit restricts results by a property of the record, such as language, publication year, publication type or indexed age group. Every limit removes records, so each needs a reason that follows from the protocol, and the reason must be reported. Language limits can bias a review toward studies published in English, and Cedar Valley applies none, because its protocol makes English and French reports eligible and asks the team to list relevant reports in other languages. The date limit follows the protocol's criterion of publication from January 2010 onward.
Limits that rely on indexing have a further weakness. Ovid's age-group limits depend on the age headings assigned to each record, so they miss every unindexed record, which is why concept B searches the population with headings and free text instead. The animal-studies lines act as a simple filter and are reported with their source.
A colleague translated the Ovid line (befriend$ or friendly visit$).ti,ab,kf. into Web of Science as TS=(befriend$ OR "friendly visit$"). Explain what it actually searches and correct it. In Web of Science, $ stands for one character or none, so the line misses befriending and friendly visiting. A corrected line is TS=(befriend* OR "friendly visit*").
Reflection
Translate four Ovid MEDLINE lines into CINAHL on the EBSCOhost platform, using these rules. A CINAHL heading is written (MH "Heading"), and a plus sign inside the quotation marks explodes it, as in (MH "Aged+"). Title and abstract must be searched as separate fields, written TI ( ... ) OR AB ( ... ). Truncation uses *. EBSCOhost proximity N followed by a number counts only the words in between, whereas Ovid adj followed by a number counts the search words too, so Ovid adj3 equals EBSCOhost N2 and adj2 equals N1. The CINAHL heading for volunteers is Volunteer Workers. The lines are: 1 exp Aged/; 2 ((social$ or emotional$) adj3 isolat$).ti,ab.; 3 (befriend$ or link worker$).ti,ab.; 4 Volunteers/. Then explain in two or three sentences why a librarian should check each heading in the CINAHL thesaurus instead of copying the MeSH heading.
Line 1 becomes (MH "Aged+"). Line 2 becomes TI ( (social* OR emotional*) N2 isolat* ) OR AB ( (social* OR emotional*) N2 isolat* ), which keeps the Ovid distance of up to two intervening words. Line 3 becomes TI ( befriend* OR (link N1 worker*) ) OR AB ( befriend* OR (link N1 worker*) ); the phrase link worker is written with proximity so that truncation can be applied to worker and plural forms are found. Line 4 becomes (MH "Volunteer Workers").
A librarian should check each heading because CINAHL Subject Headings form a separate vocabulary. Some headings share the MeSH name, some have a different name (Volunteer Workers for Volunteers, Support, Psychosocial for Social Support), and some cover a different scope or sit in a different tree, so a copied MeSH heading may retrieve nothing or the wrong records. Checking the scope note and tree for each heading, and recording the decision, also lets a peer reviewer and a reader see how the translation was made. An alternative strong answer might note that the line for link worker could also be written as a quoted phrase if the platform's help pages confirm that truncation works inside quotation marks.
Minimum 20 characters required.
Question 1: What is the difference between a database and a platform in search translation?
Question 2: A librarian translates the Ovid line (social$ adj3 isolat$).ti,ab. into CINAHL on EBSCOhost. Which proximity operator keeps the same distance?
adj3 allows two intervening words. EBSCOhost counts only intervening words, so N2 is the equivalent. Copying the number as N3 would make the line slightly broader, and W operators keep word order, which adj3 does not.Question 3: Why did the Cedar Valley team decide against the Cochrane Highly Sensitive Search Strategy for randomized trials?
Question 4: A colleague copies the Ovid term lonel$ unchanged into a Web of Science topic search. What happens?
Peer Review with PRESS and Reporting with PRISMA-S
Learning Objectives for this section
- Explain why search strategies should be peer reviewed before they are run for a review.
- Apply the six elements of the PRESS 2015 guideline to a draft search strategy.
- Write peer review feedback that cites line numbers, proposes corrections and separates required revisions from suggestions.
- Describe the sixteen PRISMA-S items and the records a team must keep while searching in order to report them.
- Write the search methods and search summary of a review according to PRISMA-S.
Introduction
A search strategy can contain errors that no one notices, because a missing synonym or a wrong line number produces results that look reasonable. The two practices in this section address that problem from different directions. Peer review checks the strategy before it is run, while there is still time to fix it. Reporting describes the strategy after it is run, so that readers can judge it and other teams can reproduce it. Figure 4 places both practices in the sequence of work covered in this lesson.
4.1 Why Searches Are Peer Reviewed
Studies of the search strategies published with systematic reviews have found errors of several kinds, including missing synonyms, missing or unexploded subject headings, incorrect line combinations, spelling mistakes and misused operators, and many of these errors could reduce recall (Sampson & McGowan, 2006). An error of this kind leaves no trace in the results, since a search that misses a set of relevant records still returns plenty of records. The protocol and the manuscript of a review are peer reviewed as a matter of routine, and search peer review applies the same logic to the step on which every later step depends. It is most useful before the searches are run, because a strategy corrected afterwards means rerunning every database and screening again.
4.2 The PRESS 2015 Guideline
PRESS (Peer Review of Electronic Search Strategies) is a guideline for the peer review of search strategies by a second searcher, usually another librarian or information specialist. Its current version, the PRESS 2015 Guideline Statement, was developed from a systematic review of the evidence on search errors, a survey of searchers and a consensus process, and it includes an evidence-based checklist organized in six elements (McGowan et al., 2016). For each element, the reviewer records comments and rates the strategy as needing no revisions, suggested revisions or required revisions, and then gives an overall rating. Reviewers usually work on the master strategy, because errors found there would otherwise be copied into every translation.
| PRESS element | Questions the reviewer asks |
|---|---|
| 1. Translation of the research question | Does the search match the review question? Are the concepts clear, and are there too many or too few of them? Is the search too broad or too narrow for the question? |
| 2. Boolean and proximity operators | Are AND, OR and proximity operators used correctly, and are parentheses nested correctly? Could NOT remove relevant records? Are proximity distances suitable? |
| 3. Subject headings | Are the headings relevant and complete? Are any too broad or too narrow? Are they exploded where appropriate, and are major-topic restriction and subheadings used appropriately? |
| 4. Text word searching (free text) | Are synonyms, spelling variants and abbreviations included? Is truncation too broad or too narrow? Are the field tags appropriate? |
| 5. Spelling, syntax and line numbers | Are there misspellings or syntax errors for the platform? Do the combination lines refer to the correct line numbers? |
| 6. Limits and filters | Are all limits and filters justified by the question and protocol? Are any useful filters missing? Are the sources of filters cited? |
4.3 A Worked PRESS Review
Before the final MEDLINE strategy shown in Section 2 existed, the intern's first complete draft was sent to a second librarian at the university for peer review. The draft is shown below with the reviewer's comments, organized by PRESS element.
Draft 1, Ovid MEDLINE(R) ALL, submitted for peer review 1 Loneliness/ 2 (lonliness or lonely).tw. 3 (social$ adj3 isolat$).tw. 4 or/1-3 5 Aged/ 6 (older adult$ or elderly or senior$).mp. 7 5 or 6 8 (social prescri$ or befriend$ or volunteer$).tw. 9 ((group or club) adj3 (art$ or exercise or music)).tw. 10 (communit$ adj3 program$).tw. 11 or/8-9 12 (evaluat$ or effect$ or outcome$).tw. 13 4 and 7 and 11 and 12 14 13 not (child$ or adolescen$).tw. 15 limit 14 to (english language and "aged (65 and over)")
| Element | Reviewer's comment | Rating |
|---|---|---|
| 1. Translation of the question | Line 12 adds a fourth concept of evaluation words. Many evaluations describe themselves only by their design or measures, so this line would remove relevant studies. Remove line 12 and combine lines 4, 7 and 11. | Required |
| 2. Operators | Line 14 uses NOT to remove records that mention children, which would remove intergenerational programs. Remove line 14. Line 3 could also search emotional isolation, disconnection and exclusion with the same adjacency. | Required |
| 3. Subject headings | Line 5 should be exploded (exp Aged/) to include Aged, 80 and over and Frail Elderly. Social Isolation is missing from concept A. Concept C has no headings; consider Social Support, Social Participation, Community Networks, Volunteers, Peer Group and Intergenerational Relations. | Required |
| 4. Text words | In line 9, art$ retrieves artery, arterial and article; use art or arts. In line 6, older adult$ as a phrase misses older people and older persons; use older adj3 with a list of nouns. Concept C lacks link worker, community connector, peer support and intergenerational terms. Use .ti,ab,kf. throughout in place of the mixture of .tw. and .mp.. | Required for line 9; suggested for the rest |
| 5. Spelling, syntax and line numbers | Line 2 misspells loneliness; lonel$ would find every form. Line 11 combines lines 8 and 9 and leaves out line 10. | Required |
| 6. Limits and filters | The English-language limit conflicts with the protocol, which makes French reports eligible and asks for reports in other languages to be listed. The age-group limit depends on indexing and misses unindexed records, and concept B already covers the population. The protocol's date limit (2010 onward) is missing. Consider adding the standard line to remove animal-only records. | Required |
The overall rating was revisions required. The intern revised the strategy, wrote a short response that listed each comment and the change made (or the reason for making no change), and returned both to the reviewer, who confirmed the revisions. The test-set check from Section 1 was then repeated on the revised strategy. The result is the strategy in Section 2.6, which was then translated for the other databases.
Writing useful feedback
The worked review illustrates the qualities that make PRESS feedback useful. Each comment names a line number, explains what the problem would do to the results, and proposes a correction. Required revisions are separated from suggestions, so the searcher knows which changes affect the validity of the search and which are matters of judgement. The reviewer also respects decisions that the searcher made for documented reasons, such as leaving context out of the search, and asks about them before recommending a change. Student peer review in this course uses the same structure.
4.4 Reporting with PRISMA-S
PRISMA-S is a sixteen-item extension of the PRISMA Statement that sets out what a review should report about its literature searches (Rethlefsen et al., 2021). It is used alongside PRISMA 2020 (Page et al., 2021) and its other extensions, including PRISMA-ScR for scoping reviews, which Lesson 10 discusses. The items fall into four groups. Several of them concern searches outside bibliographic databases, which Lesson 5 covers, and the last two concern record management, which Lesson 7 covers.
| Group | PRISMA-S items | Cedar Valley entry |
|---|---|---|
| Information sources and methods | 1. Database name, with the platform for each. 2. Multi-database searching, naming the platform and every database searched at once. 3. Study registries. 4. Online resources and browsing. 5. Citation searching. 6. Contacts with authors, experts or organizations. 7. Other methods. | Five databases, each searched separately and named with its platform. Registries, websites, citation chasing, contacts and the tested AI-assisted search are reported with the grey-literature methods (Lessons 5 and 6). |
| Search strategies | 8. Full search strategies for every database and source, copied exactly as run. 9. Limits and restrictions, with justification. 10. Search filters, cited. 11. Prior work reused or adapted. 12. Updates. 13. Dates of searches. | All five strategies in an appendix. Date limit of 2010 onward from the protocol, and no language limit. Animal-only lines cited, with no design filter. No earlier strategy reused. All databases searched on 10 February 2026. |
| Peer review | 14. The search peer review process. | MEDLINE strategy reviewed by a second librarian with PRESS 2015 before the searches were run. |
| Managing records | 15. Total records from each database and other source. 16. De-duplication methods and software. | Records per database in the search summary below. De-duplication reported as described in Lesson 7. |
Keeping a search log
A team can report these items only if it records them while searching, because platforms change and several details cannot be recovered later. A search log is a running record, kept for every search, of the database and platform, the coverage label the platform displays (for example, 1946 to February 09, 2026), the date, the person who ran it, the full strategy with the number of records for each line, the limits applied, the name of the exported file, and notes on anything unusual. Ovid and EBSCOhost can export the search history with line counts, and saving that export on the day of the search is the simplest way to preserve the strategy exactly as run. Some teams also deposit their strategies in an open archive such as searchRxiv so that others can reuse them.
A reporting example
The table and paragraph below show how the Cedar Valley database searches will be reported in the methods section of the scoping review. The record counts are those of the fictional project, and the five databases together retrieved 2,480 records.
| Database | Platform and coverage | Date searched | Records |
|---|---|---|---|
| MEDLINE | Ovid MEDLINE(R) ALL, 1946 to February 09, 2026 | 10 February 2026 | 742 |
| Embase | Ovid, Embase 1974 to 2026 February 09 | 10 February 2026 | 816 |
| CINAHL | EBSCOhost | 10 February 2026 | 388 |
| APA PsycInfo | Ovid, 1806 to February Week 1 2026 | 10 February 2026 | 296 |
| Web of Science Core Collection | Clarivate; Science Citation Index Expanded and Social Sciences Citation Index, years as licensed by the university | 10 February 2026 | 238 |
| Total | 2,480 |
Example methods text written to PRISMA-S
A university librarian developed the search strategy with the review team, using a concept table and a test set of ten known studies. A second librarian peer reviewed the MEDLINE strategy with the PRESS 2015 guideline before the searches were run (McGowan et al., 2016). The team searched Ovid MEDLINE(R) ALL (1946 to February 09, 2026), Embase on Ovid (1974 to 2026 February 09), CINAHL on EBSCOhost, APA PsycInfo on Ovid (1806 to February Week 1 2026) and the Web of Science Core Collection (Science Citation Index Expanded and Social Sciences Citation Index) on 10 February 2026, searching each database separately. The strategies combined subject headings and free-text terms for loneliness or social isolation, older adults and community-based interventions, and the full strategy for each database, as run, is given in Appendix 1. In line with the protocol, the searches were limited to records published from 2010 onward. Records indexed only as animal studies were removed in MEDLINE and Embase with lines from Cochrane guidance (Lefebvre et al., 2023). No language limits or study design filters were applied, and no previously published strategy was reused. The database searches retrieved 2,480 records (MEDLINE 742, Embase 816, CINAHL 388, APA PsycInfo 296 and Web of Science 238), which were de-duplicated as described in the next section. Grey-literature, website and citation searches are reported separately.
The paragraph covers items 1, 2, 8, 9, 10, 11, 13, 14 and 15, and the appendix supplies the strategies required by item 8. Item 16 is reported in the record-management section of the review, where Lesson 7 shows how the 610 duplicates are removed to leave 1,870 records for screening, and items 3 to 7 are reported with the grey-literature methods.
Updating searches
Searches age. Cochrane's conduct standards for intervention reviews expect searches to be rerun within twelve months before a review is published, and many other review teams follow similar practice. The Cedar Valley brief is due within twelve weeks, and no update is planned in that time. The team saves every strategy on the platform where it was run, so the searches can be rerun quickly if the review is later published or updated. Any update is reported under PRISMA-S item 12 with its date and method.
From question to finished search
The lesson's steps form one sequence for any rapid scoping review. First, the question becomes a concept table with two to four concepts, listing MeSH headings and free-text synonyms for each, with a note of any element of the question that will be applied at screening instead. Second, the MEDLINE strategy is written in Ovid syntax in numbered lines and checked against three to five studies already known to be relevant. Third, it is translated into at least one further database, such as CINAHL on EBSCOhost or APA PsycInfo, and the heading decisions are recorded. Fourth, a second searcher reviews the MEDLINE strategy with the six PRESS elements, and the author revises it with a short response to each comment. Finally, a PRISMA-S search log records the database, platform, coverage, date, limits and number of records for each search.
Reflection
Write a search methods paragraph of 120 to 200 words that reports the following database searches according to PRISMA-S, the reporting guideline for literature searches. A health sciences librarian built the search for a review of school-based physical activity programs (the details are fictional). A second librarian peer reviewed the MEDLINE strategy with the PRESS 2015 guideline before searching. The databases were MEDLINE on Ovid (coverage 1946 to March 3, 2026), Embase on Ovid (coverage 1974 to 2026 March 3) and CINAHL on EBSCOhost, each searched separately on 4 March 2026. The searches were limited to publications from 2015 onward, which the protocol justifies because a provincial curriculum change took effect that year. No language limit and no search filter were used, and no earlier strategy was reused. MEDLINE retrieved 512 records, Embase 640 and CINAHL 233. The full strategies are in Appendix 2. After the paragraph, name two PRISMA-S items that this paragraph cannot cover and say where in the review they would be reported.
A health sciences librarian developed the search strategy with the review team, and a second librarian peer reviewed the MEDLINE strategy with the PRESS 2015 guideline before the searches were run. The team searched MEDLINE on Ovid (1946 to March 3, 2026), Embase on Ovid (1974 to 2026 March 3) and CINAHL on EBSCOhost, searching each database separately on 4 March 2026. The full strategy for each database, as run, is given in Appendix 2. In line with the protocol, the searches were limited to publications from 2015 onward, because a provincial curriculum change took effect in that year. No language limits or search filters were applied, and no previously published strategy was reused. The searches retrieved 1,385 records (MEDLINE 512, Embase 640 and CINAHL 233).
The paragraph cannot cover item 16 (de-duplication), which belongs in the record-management section with the name of the software and the number of duplicates removed. It also cannot cover items 3 to 7, such as citation searching or contact with experts, which are reported with the grey-literature and supplementary search methods. Item 12 (updates) would be added if the searches were rerun before publication.
Minimum 20 characters required.
Question 1: When is PRESS peer review most useful, and who usually carries it out?
Question 2: A peer reviewer notices that line 11 of a draft reads or/8-9, although lines 8 to 10 all belong to the concept. Under which PRESS element does this comment fall?
Question 3: Which statement describes PRISMA-S item 8, full search strategies?
Question 4: The Cedar Valley team reports that five databases retrieved 2,480 records, gives the count for each database, and states that all were searched on 10 February 2026. Which PRISMA-S items do these details address?
Final Assessment
Bringing It All Together
This lesson followed the Cedar Valley evidence team as it turned a review question into a database search that another team could judge and reproduce. The work began with a concept table, which decided which parts of the question to search and which to apply at screening, and listed subject headings and free-text synonyms for each concept. A test set of known studies showed where the draft fell short. The concepts were then written in Ovid syntax as numbered lines that use Boolean operators, truncation, wildcards, adjacency and explicit field tags, with limits that follow from the protocol.
The master strategy was peer reviewed with the PRESS 2015 guideline before it was translated, so that corrections carried into every database. Translation changed both the vocabulary, because MeSH, Emtree, CINAHL Subject Headings and the APA Thesaurus differ, and the syntax, because Ovid, EBSCOhost, Embase.com and Web of Science use different symbols and count proximity differently. A search log kept during searching allowed the team to report its five database searches according to PRISMA-S, with full strategies, dates, limits and record counts.
Key Takeaways from this lesson
- Most review searches combine two to four concepts, and parts of the question that authors describe inconsistently, such as setting or design, are better applied at screening.
- A concept table lists the subject headings and free-text terms for each concept and records the decisions behind them, which supports peer review and translation.
- Each concept is searched with both subject headings and free text, combined with OR, because recent and unindexed records carry no headings.
- Exploding a heading searches its narrower headings as well, while major-topic restriction lowers recall and is rarely used in reviews.
- NOT removes any record that contains the excluded term, so it can remove relevant studies and should be used only in tested forms such as the animal-studies line.
- Truncation stems must be long enough to avoid unrelated words, and adjacency operators find word-order variants that phrase searches miss.
- Translation changes the vocabulary, which belongs to the database, and the syntax, which belongs to the platform, and every translated heading must be checked in the target thesaurus.
- Platforms assign different meanings to wildcard symbols and count proximity differently, so Ovid adj3 corresponds to N2 in EBSCOhost and NEAR/2 in Web of Science.
- Validated search filters and limits each need a reason that follows from the protocol, and both must be reported.
- PRESS peer review before searching catches errors that results would never reveal, and a search log kept during searching makes PRISMA-S reporting possible.
Core Concepts Reviewed
Section 1: search concepts, the concept table, subject headings and free-text terms, explosion, scope notes, indexing delays and the test set.
Section 2: Boolean operators, parentheses and numbered lines, truncation, wildcards, phrase searching, adjacency, field tags and the full Ovid MEDLINE strategy.
Section 3: databases and platforms, translation of vocabulary and syntax into CINAHL, Embase, APA PsycInfo and Web of Science, validated search filters and limits.
Section 4: the PRESS 2015 guideline and its six elements, a worked peer review, the sixteen PRISMA-S items, the search log and a reporting example.
The final reflection asks you to apply the PRESS elements and PRISMA-S to a colleague's draft search.
Reflection
A colleague's scoping review asks which community paramedicine programs have been evaluated for older adults living in rural areas. Their protocol makes English and French reports eligible. In Ovid, a slash marks a subject heading, exp explodes a heading, $ truncates a word, adj3 finds two terms in either order with up to two words between them, and .ti,ab. restricts terms to the title and abstract. Their draft Ovid MEDLINE strategy is: 1 exp Aged/; 2 (older or elderly or senior$).ti,ab.; 3 or/1-2; 4 (community paramedic$ or paramedic$).ti,ab.; 5 Rural Population/; 6 (rural or remote).ti,ab.; 7 5 or 6; 8 3 and 4 and 7; 9 limit 8 to english language. The six PRESS elements are translation of the question, Boolean and proximity operators, subject headings, text words, spelling and syntax and line numbers, and limits and filters. Write PRESS-style feedback that identifies at least four issues across at least three elements, giving the line number and a correction for each, and then list the information the colleague must record in a search log so that the search can be reported with PRISMA-S.
Limits and filters (required). Line 9 limits results to English, which conflicts with a protocol that makes French reports eligible. Remove the limit, or apply language at screening. Subject headings (required). The paramedicine concept (line 4) has no headings. Check MeSH for headings such as Emergency Medical Technicians and Emergency Medical Services, read their scope notes, and add the relevant ones to the concept with OR. Line 5 could be joined by Rural Health Services if its scope note fits. Text words (suggested). In line 2, older on its own retrieves many unrelated uses; use (older adj3 (adult$ or people or person$ or patient$)).ti,ab.. Line 4 lists community paramedic$, which paramedic$ already covers; add synonyms such as mobile integrated health and extended care paramedic$. Line 6 could add rurality, northern and isolated communit$. Translation of the question (no revision). Three concepts (older adults, paramedicine, rural setting) match the question.
For the search log, the colleague should record the database and platform, the coverage label Ovid displays, the date of each search, the full strategy exported with the number of records for each line, the limits applied and their justification, the total records retrieved, the name of the exported file, and the name of the PRESS reviewer and the date of the review with a note of the changes made.
Minimum 30 characters required.
Final Knowledge Assessment
Question 1: What is the main purpose of a concept table in building a review search?
Question 2: Which Ovid line correctly combines a subject heading and free text within the older adults concept?
Question 3: When the Ovid term neighbo?rhood is translated into CINAHL on EBSCOhost, what is the correct form?
Question 4: Why does the Cedar Valley search apply no language limit?
Question 5: Which translation of the MEDLINE heading Volunteers matches the Cedar Valley heading decisions for CINAHL and Embase on Ovid?
/exp form belongs to Embase.com, and a TI search is free text.Question 6: Under which PRESS element does a reviewer place the comment that a draft searched (lonliness or lonely).tw.?
lonel$ under the text-word element.Question 7: Running concepts A and B without concept C also retrieved all nine Cedar Valley test-set studies indexed in MEDLINE, along with many more records. What did the team conclude?
Question 8: Which part of the Cedar Valley MEDLINE strategy deals with the ambiguous word isolation?
Question 9: A reader asks why line 30 of the MEDLINE strategy limits records to 2010 onward. Which answer meets PRISMA-S item 9?
Question 10: In the Cedar Valley reporting example, which detail satisfies PRISMA-S item 1 for the MEDLINE search?
Question 11: Which statement about validated search filters is accurate?
Question 12: Why does the Cedar Valley search avoid major-topic (focus) restriction on its subject headings?
Question 13: After a PRESS review rated several comments as required revisions, what should the searcher do?
Question 14: Lesson 7 removes 610 duplicates from the 2,480 database records. Which PRISMA-S item covers how this is done?
Question 15: Which combination of syntax should a Web of Science translation of the Cedar Valley loneliness concept use?
Glossary: Key Terms, People & Frameworks
📚 Reference page, available throughout the lesson
Terms, tools and people introduced in this lesson on building and documenting database searches.
Loneliness/.
exp in Ovid.
volunteer$ in Ovid or volunteer* elsewhere.
behavio?r in Ovid; its meaning differs between platforms.
adj3 in Ovid, N2 in EBSCOhost and NEAR/2 in Web of Science.
.ti,ab,kf. for title, abstract and author keywords in Ovid MEDLINE.