There are videos and written guidance for using CINAHL and other useful databases to do a structured search, which cover:
This video from the University of East London gives a useful summary on conducting a systematic literature search.
SuRe Info have also produced a chapter summarising the current research findings within search strategy development: https://sites.google.com/york.ac.uk/sureinfo/home/search-strategy-development
The frameworks are used to help formulate a clinical question and define the main concepts and search terms. The PICO framework assists in helping to identify the patient or population we intend to study, the intervention or treatment we plan to use, the comparison of one intervention to another (if applicable) and the outcome we anticipate. These make up the four elements of the PICO model: Patient/Problem, Intervention, Comparison and Outcome. The I can be replaced by an E for exposure or experience if that is more appropriate.
These elements then form the basis of the search terms we use in the databases.
|
Framework item: |
Think about: |
Example: |
|
Patient Problem (or Population) |
What is the or problem? What are the patient's demographics such as age, gender and ethnicity? |
Work-related neck muscle pain |
|
Intervention |
What type of intervention is being considered? For example is this a medication of some type, or exercise, or rest? |
Strength training of the painful muscle |
|
Comparison or Control |
Is there a camparison treatment to be considered? The comparison may be with another medication, another form of treatment such as exercise, or no treatment at all. |
Rest |
|
Outcome |
What would be the desired effect you would like to see? What effects are not wanted? Are there any side effects involved with this form of testing or treatment? |
Pain relief |
When forming your question using the PICO framework it is useful to think about what type of question it is you are asking, (therapy, prevention, diagnosis, prognosis, etiology). The table below illustrates ways in which Problems, Interventions, Comparisons and Outcomes vary according to the type of systematic review question:
The Creating a PICO Scenario tutorial, from The University of York, also explains the PICO formula and has some examples and activities to test your knowledge.
For further help see the 'Developing inclusion & exclusion criteria' page for an example of how a Cochrane review is broken down into its PICO elements.
Some research does not fit into the PICO formula and there are other formulas or tools that you could consider using to break your search question down into concepts. These include:
PICOST/ PICOTS (As PICO but with additional areas to consider): Population, Intervention, Comparison, Outcome, Situation, Type of Study
PCC: Population, Concept, and Context [often used in Scoping Reviews]
PESTEL: Political, Economic, Social, Technological, Environmental and Legal Factors
SPICE: Setting, Population or Perspective, Intervention, Comparison, Evaluation
ECLIPS [management and service related issues]: Expectations, Client Group, Location, Impact, Professionals Involved, Service
MIP [medical ethics review]: Methodology, Issues, Participants
SPIDER: Sample, Phenomenon of interest, Design, Evaluation, Research type
You should consult your supervisor regarding your choice of framework and bare in mind that the more elements it includes, the more difficult it can be to retrieve relevant research.
There are a number of advanced techniques you can use to improve the thoroughness of your searches. The main advanced searching techniques used are: truncation, wildcards, phase searching and proximity searching.
The way that you search using these techniques varies for each database, so always check the help screens on the databases if you are unsure. Databases that the library subscribes to often have a blue help button 
which will take you to the help page.
In some databases you can also use the thesaurus 'mapping' function to make use of the subject or medical headings. There is more information on this in the Using Subject Headings tab.
Truncation
On the EBSCO platform, the truncation symbol is an asterisk *, and on the OVID platform it can be an asterisk * or the dollar sign $. It can help you to get more results quickly and easily. Some search terms can have lots of different, but useful, endings. For example, your search might be looking for information on nursing, but you would also like your results to find articles which talk about the nurse or nurses. Nursing, nurse and nurses all start with the same four letters so using truncation means that you don’t have to write out all of those different endings. Simply type the beginning of the word and then replace the ending with the asterisk *. So, a search for nurs* would find nurse, nurses and nursing.
In the Cochrane Library you can also use truncation * at the beginning of term, for example *glycemia would find results with the words hyperglycemia and hypoglycemia.
Wild Cards
The wild card symbols on the EBSCO and OVID platforms are a question mark ? and a hashtag # They are used to replace one or more characters within a word.
The hashtag in EBSCO stands for zero or one character. For example you could use p#ediatric to find results which contain the terms pediatric or paediatric. However, in OVID you would need use the question mark to do this, for example p?ediatric
The question mark is used in EBSCO to search for terms with a single unknown character, for example a search for organi?ation would find organisation and organization. In OVID, you would need to use the hashtag to do this, for example organi#ation.
Note that when using any wildcard in a search term in EBSCO, the plural or possessive forms of the word and any synonyms will not automatically be searched. For example; when searching for colo#r, the plural words colors and colours are not searched.
Phrase Searching
Phrase searching helps to keep your search terms together, in the order they are written, usually using the double speech marks “”, for example, "physical therapy", "lung cancer" or "cognitive behavioural therapy".
When searching for keywords in OVID (Embase, Maternity and Infant Care etc,), the database automatically treats the search terms you enter on a search line as a phrase, without having to use the double speech marks. However, in EBSCO (CINAHL, Medline, PsycInfo etc.) the database automatically retrieves results which have your terms within 5 words of each other and you need to use the double speech marks if you want them to be treated as a phrase.
In the EBSCO databases, when you conduct a search, you may get results that include both the singular and plural versions of your search terms:
When a plural word is searched, the search engine will automatically search for the singular version of the term. If the plural word is spelled differently, (e.g. child, children), a search is not expanded unless the "Apply additional terms to query" expander is checked.
As the OVID databases automatically treat keywords as phrases, you will need to specify if you are searching for the singular or plural version of your terms. You could use truncation to help with this.
You can use truncation and phrase searching together, for example "physical therap*" (in EBSCO) or physical therap* (in OVID). Phrase searching can sometimes be too restrictive, so as long as the database supports it, you might prefer to use proximity searching.
Proximity Searching
Proximity searching is a way to search for two or more words that occur within a certain number of words from each other. It helps narrow down results, but is broader than phrase searching.
In EBSCO you need to use the Near (N) or the Within (W) operator to do this. You use the operator followed by a number, to indicate how many words can be between each term, e.g. N3 or W5.
In OVID you use the adjacency operator (adj):
In the Cochrane Library you need to use the NEAR and NEXT functions.
Here is a sample search string from the systematic review Occupational therapy for adults with problems in activities of daily living after stroke. It is part of a CINAHL search (in EBSCO) and it uses truncation, proximity searching and a wildcard. You can see the full search history in the appendices.
When you search for information, it’s very easy to get too many results or results that aren't very relevant. When you type in more than one search term, you can link them together with AND, OR, NOT. These are known as Boolean operators.
OR
OR helps you to get more results. It’s important to think about all the ways an authors could have described a topic, in order to make sure all the possible, useful research articles come back in your search. Once you’ve identified the main keywords you can use OR to search for them all. In literature searching this is called Sensitivity. It shows you are trying to find all the relevant research for your topic.
AND
Using AND will reduce the number of results you get, but should make them more specific to your research topic, as the results which comeback should contain a combination of all of you keywords. In literature searching this is called Specificity and it shows you have conducted a focused search.
NOT
Using NOT will reduce the number or results you get as it will exclude the specified term(s). If you have decided to use the NOT operator in your search, it needs to be used with caution. For example, the search 'heart not lung' finds items that contain the term heart but do not contain the word lung. This would mean that you would lose all the articles which talk about the lung, even when both terms are listed (and these could be relevant).
For more information and examples of how to use Advanced Search techniques and Boolean operators in EBSCO (CINAHL) see the searching page on the CINAHL LibGuide.
Subject headings or medical subject headings (MeSH) are a list of words or phrases that use controlled vocabulary to describe specific concepts. They act like a thesaurus and index terms so that they will retrieve references on a topic regardless of the wording used by individual authors.
Subject headings can be useful as they allow you to explore associated (broader, narrower and related) terms in the subject index. The terms are assigned by experts (humans not machines) who classify the article by tagging it with subject headings that relate to the content. Some tags represent the main focus of the article and some refer to secondary aspects of the work.
In EBSCO, the subject headings are in the item record The are split up into Major Subjects (main focus) and Minor Subjects (secondary aspects).
As different databases use different subject indexes (Medline uses MeSH, EMBASE uses EMTREE), you cannot use the same subject headings from one database in another. So, you will need to search for each concept in each database, in order to locate the relevant subject heading (if it exists) and add that to your search.
When using free text, keyword, or ‘natural language’ searching, results are usually found if the words you are searching for are in the article title, abstract or keywords used in the item record. So, in order to find relevant articles you will need to use the same terminology as the author(s).
One of the problems with free text searching is the ambiguity of ‘natural language’. You will need to ensure when you are searching using free text/keywords that you include synonyms and variant forms of the same word or phrase. Think about US and UK spellings, plurals, hyphenated words and abbreviations.
To search for a subject heading in EBSCO, tick the box called Suggest Subject Terms, enter your search terms and click on search.
This will take you to the subject index. It will show where your term appears in the index and it will give you options to look: explode the term, make the term a major concept and to look at the Scope note. Once you have made your choice (the example below shows that the term stroke has been chosen as well as the option to explode the term), you click on the search database button to add it to the search. The default is to include all the subheadings listed, but you can choose to limit your search (by checking the boxes next to the relevant subheadings on the right hand side of the index) if you want to.
On the Ovid platform a subject heading search is shown with a / after the term. If the subject heading has been exploded to include narrower more specific terms then this will show with exp before it. If the subject heading has been focussed (limiting to articles where the selected subject heading is a major concept of the article) then an asterisk will appear at the beginning of the term
exp *cerebrovascular accident/ - exploded and focused/major concept search
To search for a subject heading in OVID, tick the box called Map Term to Subject Heading, enter your search terms and click on search.
This will take you to the subject index (as you can see below, the when searching for the subject heading Stroke in OVID, it is suggesting we use the index term cerebrovascular accident instead). If you click on the blue link for the subject heading, it will show where your term appears in the index. You also have the options to explode the term, make the term a major concept and to look at the Scope note. Once you have made your choice (the example below shows that the term cerebrovascular accident has been chosen as well as the option to explode the term), you click on the continue button to add it to the search. The default is to include all the subheadings (listed on the following page) but you can choose to limit your search (by checking the boxes next to the relevant subheadings) if you want to.
In the search strategies of some Cochrane reviews you might notice that they use .tw or .ab,ti (OVID) and TI and AB (EBSCO) when searching for keywords. This indicates that they are searching for keywords in just the title and abstract fields (.tw also searches for keywords in the drug trade name). This usually occurs alongside a search using the subject headings.
The search examples below, both come from the Cochrane Review Telerehabilitation services for stroke
This example is from the CINAHL (EBSCO) search:
This example is from the EMBASE (OVID) search:
Using keyword searching limited to the Title and Abstract field should reduce the number of results which are retrieved in error or are only a minor part of your subject. However, please be aware that you will need to ensure that you have definitely also included all relevant subject headings in your search strategy otherwise you risk missing out on useful results.
In order to carry out a free text search in just the title and abstract fields in EBSCO you need to specify that your keywords only appear in those fields.
For example, in CINAHL, you need to type your search term in the box and then change the 'select a field' drop down box to choose either TI Title or AB author.
You can then combine these terms, with all the other relevant synonyms and your subject headings using OR in the Search History. For example:
In OVID, you can use the Textword Field search (.tw) to look for your keywords in the title, abstract or drug trade name.
You can then combine these terms, with all the other relevant synonyms and your subject headings using OR in the Search History. For example:
You do not have to limit your keyword searches to the title or abstract fields. In EBSCO, you can leave 'Select a field optional' and in OVID, you can just type your keyword in and press search without putting .tw at the end of the term. This way of searching will give you more results.
Scope Notes
And in OVID it looks like this:
When you select explode a term in the subject index, it will automatically include all articles which have also been tagged with any more specific/narrower terms in the thesaurus under the subject heading you have chosen to search. The examples for Stroke from CINAHL and Cerebrovascular accident from Embase, are below:
In general it is good practice to explode the Subject Headings in your search. If you feel that too much irrelevant material is being retrieved then explore the thesaurus to see whether you need to pick a high level subject heading (not exploded) and also only some of the more specific subject headings which fall beneath it in the thesaurus.
Focus
If you select Focus you will restrict your results to only those articles which the indexer feels the subject heading you have selected to search is key to what the article is about.
Use Focus with care in a systematic review as it will dramatically reduce the number of results retrieved. Initially it would be a good idea to see what the results are without focusing after you have combined your terms.
It is possible to both Explode and Focus a subject heading search. By applying both Explode and Focus you will retrieve articles tagged with your subject heading and the narrower subject heading terms that fall underneath it in the thesaurus (Explode), but also limit (reduce) the results to where either the top level subject heading or any of its narrower terms have been identified by the indexers as being key/the focus/the major concept which the article is about
This video from EBSCO Tutorials demonstrates how to create a search using the CINAHL/MeSH Headings functionality in EBSCOhost.
This video from The University of Technology Sydney gives a demo of how to do a subject heading search for literature using Embase in OVID.
SuRe Info have a chapter summarising the current research findings regarding Search Filters: https://sites.google.com/york.ac.uk/sureinfo/home
The Cochrane Library Handbook lists filters for RCTs in the Medline database on the Ovid and PubMed platforms. You can find these filters in he Handbooks' chapter four: https://training.cochrane.org/handbook/current/chapter-04#section-4-4-7
You can filter by study design e.g. only RCTs or focus e.g. quality of life or prognosis:
Other pre-tested search filters for different types of experimental design or focus and for different databases which you can copy and paste line by line into your search are also available from:
You can save search filters after you have typed them in by choosing to save your search history – then you can simply re-run them when you wish to apply them to a specific search. The filters look complicated but you should be able to cut and paste them into the search box in the database. Remember though – each line of the filter is a separate search on the database and you will need to combine them in exactly the same way as set out in the filter before using AND to apply them to your search strategy.
New Limit - Special Ovid Filters for Embase
Ovid has recently made available a number of search filters based on recommended searches from the Europe Medicines Agency, Cochrane and published hedges from expert users. Limits will be available for the following topics and special situations: Adverse effects, Children, Elderly, Pregnancy, and Humans only (removes records about animals).
Published Search Filter for UK research - Medline and Embase
A group of researchers have published tried and tested search filters you can use to limit your results to research about the UK for the Medline and Embase databases:
Ayiku, L. , Levay, P. , Hudson, T. , Craven, J. , Finnegan, A. , Adams, R. and Barrett, E. (2019), The Embase UK filter: validation of a geographic search filter to retrieve research about the UK from OVID Embase. Health Info Libr J. doi:10.1111/hir.12252
Clinical queries:
Clinical Queries are specific search strategies (“hedges”) which can be applied to retrieve clinically-relevant and scientifically-sound results from the CINAHL® databases. These strategies are created in collaboration with the Health Information Research Unit (HIRU) at McMaster University, and are designed for clinician use. https://connect.ebsco.com/s/article/CINAHL-Clinical-Queries?language=en_US
Clinical Queries allow the user to limit searches using specific search strategies to aid in retrieving scientifically sound and clinically relevant study reports indexed in MEDLINE databases: https://connect.ebsco.com/s/article/What-are-the-search-strategies-used-by-the-MEDLINE-Clinical-Queries?language=en_US
Search Filters for RCTs
The Technical Supplement of the Cochrane Handbook contains approved filters for retrieving RCTs in MEDLINE, CINAHL and EMBASE.
MEDLINE
There are two RCT filters for MEDLINE. The Cochrane Handbook recommends combining the sensitivity-maximizing version with a highly sensitive subject search. If this broad search produces more results than can be practically managed, the alternative sensitivity- and precision-maximizing version should be used instead.
Cochrane Highly Sensitive Search Strategy for identifying randomized trials in MEDLINE: sensitivity-maximizing version (2008 revision), adapted from OVID format for EBSCO MEDLINE.
Explanation of field codes and symbols
PT = publication type
AB = abstract
TI = title
MW = a floating subheading. It finds any subject heading with the sub-heading listed, i.e. in this case, any subject heading with the sub-heading drug therapy.
MH = a major subject heading
+ = an exploded subject heading
SU = any subject heading (major or minor), not exploded
Cochrane Highly Sensitive Search Strategy for identifying randomized trials in MEDLINE: sensitivity- and precision-maximizing version (2008 revision); adapted from OVID format for EBSCO MEDLINE.
The field codes and symbols are explained above.
CINAHL
The Cochrane Handbook recommends an RCT filter for CINAHL that was published in 2019.
Explanation of field codes and symbols
MH = a major subject heading
TI = title
AB = abstract
PT = publication type
W = proximity operator preserving the order of the words, so cluster W3 RCT finds cluster within 3 words of RCT, but cluster must always come first.
+ = an exploded subject heading
random* = truncation symbol * finding words that begin with the same stem. In this example, it finds random, randomised, randomized, randomisation, randomization etc.
EMBASE
The Cochrane Handbook also includes an RCT filter for EMBASE, published in 2019.
Cochrane Highly Sensitive Search Strategy for identifying controlled trials in Embase: (2018 revision); Ovid format
Explanation of field codes and symbols
/ = Emtree (subject) heading
.ti. = title
.ab. = abstract
.ti,ab. = title OR abstract
adj = proximity search. If there’s no following number it means the terms are next to each other (adjacent). Numbers can be added to adj to define proximity, adj3, adj5 etc.
*1 = truncation symbol * can be followed by a number indicating how many letters after the symbol you want the database to search, e.g. group*1 would find group OR groups, but not groupings, groupwork etc.
The $ can also be used as a truncation symbol for searches on the OVID platform.
or/1-19 = shorthand to combine lines 1 to 19 with OR. You can use the check the boxes to select lines and combine using the OR button instead, or type 1 OR 2 OR 3 etc. into the search box.
? = wildcard to find variant spellings, but only where a letter is definitely present, so use to find randomise or randomize, organise or organize etc, but not for behaviour or behaviour, colour or color etc where there can be an extra letter present.
Search filters for Qualitative Research
MEDLINE
There some filters for qualitative research listed on the ISSG Search Filter Resource.
A number of these have been reviewed for their performance (Wagner et al., 2020) and two are highlighted: a very short one, for sensitivity (Health Information Research Unit, 2016) and a longer one that provides the best balance between sensitivity and specificity (University of Texas Health Science Center at Houston, 2018).
Sensitivity maximising qualitative research filter for MEDLINE (Health Information Research Unit, 2016), adapted from OVID format for EBSCO MEDLINE.
Explanation of field codes and symbols
TI = title
AB = abstract
MW = a floating subheading. It finds any subject heading with the sub-heading listed, i.e. in this case, any subject heading with the sub-heading psychology
MH = a major subject heading
+ = an exploded subject heading
interview* = truncation symbol * finding words that begin with the same stem. In this example, it finds interview, interviews, interviewing, interviewer, interviewers, interviewee, interviewees etc.
Sensitivity- and precision-maximizing qualitative research filter for MEDLINE (University of Texas Health Science Center at Houston, 2018), adapted from OVID format for EBSCO MEDLINE.
Explanation of field codes and symbols
TI = title
AB = abstract
N = proximity operator allowing flexibility in the order of the words, so guide N3 interview* finds guide within 3 words of interview* but either word can come first.
interview* = truncation symbol * finding words that begin with the same stem. In this example, it finds interview, interviews, interviewing, interviewer, interviewers, interviewee, interviewees etc.
MH = a major subject heading
Grey literature is material which is not usually published through normal channels. Examples of grey literature include: government reports, theses, conference papers and abstracts, discussion papers, newsletters, PowerPoint presentations, best practice documents, guidelines and protocols.
This helpsheet details the best sources to use to find grey literature in the area of health and social care: Helpsheet on Grey Literature
Public Health England have also compiled an index of grey literature: Public Health England: Index of Grey Literature and Alternative Sources and Resources
This short video from the University of Guelph defines and describes grey literature. It discusses how it can be useful to your research.
You can search for and download electronic theses using ETHOS which is a British Library database of theses published by UKHE institutions. A few other countries also make their national theses collections available online.
** Currently Unavailable **
The aim of EThOS is: - To offer a 'single point of access' where researchers the world over can access ALL theses produced by UK Higher Education - To support Higher Education Institutions through the transition from print to e-theses - To help UK Higher Education Institutions expand available content by digitizing paper theses - To demonstrate the quality of UK research and help attract students and research investment into UK High Education
Accessibility Statement (This link opens in a new window)
A selection of some other useful resources for grey literature in health are listed below:
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This link opens in a new window
This link opens in a new windowHMIC contains two bibliographic databases: King's Fund Database - records of material in the independent health charity's library. DHdata - the Department of Health Library & Information Services Database. HMIC contains records from journals, books, reports, official publications and 'grey' literature, covering all areas of health management and services.
To access HMIC click the continue button then scroll down the resources list and click on Health Management Information Consortium.
This link opens in a new window This link opens in a new windowSocial Care Online provides access to the UK's most complete range of information and research on all aspects of social care. It contains all the information previously held in both the electronic Library for Social Care (eLSC) and CareData and much more. New content is added daily, covering all aspects of social care, including fostering, mental health and human resources and much, more.
Accessibility Statement (This link opens in a new window)
Handsearching is a recognised tool within systematic reviews. It is necessary to find studies that may not have been indexed correctly or adequately or which may be missing from the database altogether. It is a manual process which involves looking through relevant journals page by page or by using their table of contents. It can also involve looking at the references in each journal article found.
There is more information about handsearching available in the resources below.
Citation indexes can helpful for discovering other relevant research which may have been missed in the database searches. They are available in databases like Web of Science and Scopus as well as search engines like Google Scholar and ResearchGate. The indexes allow you to look at the cited by information for research which you know is of interest, so you can see who has cited them since they were published. Some search engines, and journal websites also offer recommended for you links which can also lead to further research of interest.
This link opens in a new window
This link opens in a new windowEasy to use and comprehensive, Scopus is the world’s largest abstract and citation database of peer-reviewed literature covering 20,500 journals.
Further Help and guidance is available at http://libguides.tees.ac.uk/cinahl/support - please select the Scopus tab
Accessibility Statement (This link opens in a new window)
This link opens in a new window This link opens in a new window This link opens in a new windowAn abstracting & indexing database covering over 12,000 journals via the Science Citation Index Expanded, the Social Sciences Citation Index, and the Arts and Humanities Citation Index. Conference proceedings for science and social sciences & humanities are also indexed
Accessibility Statement (This link opens in a new window)
You may be able to get hold of further information about unpublished or ongoing research by making contact with authors and organisations involved in the research. If you have a supervisor for your systematic review, remember to also check with them to see if they can spot any key research which is not included in your results.
You can set up alerts for individual journals so that you are alerted whenever a new issue is available. You can set this up via an individual database or direct with the publisher of the journal. You can also use a service such as JournalTOCs.
JournalTOCs is the largest, free collection of scholarly journal Tables of Contents (TOCs): over 23,000 journals from 2029 publishers. It is for researchers, students, librarians and anyone looking for the latest scholarly articles and alerts you when new issues of your followed journals are published.
In Discovery and most databases you can save your searches and set an alert to inform you when new articles have been added that match your search keywords. You will need to be signed in to be able to do this.
RSS (Really Simple Syndication) feeds, also known as 'news feeds', are another way of keeping up to date by allowing you to see when websites of your choice have added new content.
RSS can be used as an alternative to email alerts, allowing you to set up feeds from online databases in your subject area to see details of new journal articles that have been added to the database.
Other web-based services e.g. BBC News website, support RSS and you can set up a feed for an area of news that interests you.
More information on how to start using RSS feeds from:
You can monitor the Web for new content by using Google Alerts to get email updates of the latest relevant Google results (web, news, etc.) based on your choice of query or topic.
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