1. Effective Literature Searching Some frequently asked questions
Hello and welcome to this series of short videos on the six steps to effective literature searching
My name is Jane Falconer and in this video I will be showing you how to access the Library’s electronic resources if you are not using a computer at LSHTM.
Library & Archives Service

2. I’ve never done any searching before, where should I begin?1
Define your topic 2
Choose the resources to search 3
Choose your search terms 4
Compile the strategy and run the search 5
Find the full text
You should work through the 5 steps of an effective literature search. Working logically through these steps ensures your search is focused, systematic and effective.
The Library has produced a handbook taking you through each step, you can download it at
These are the 5 steps. You’ll notice that it is not until step 4 that you actually run your search in a database. Some people find this surprising, but it is important that you don’t miss out the 3 preparatory stages. If you don’t spend some time planning first you will find it frustrating and difficult to retrieve material relevant to your topic.

3. I have a rough idea of my topic, how can I turn this into something I can search on?
You need to work through step 1 of the literature search process: defining your topic. The next few slides will take you through the basics to achieve this, but this help sheet gives more detailed information
Firstly, you must be very specific about what it is you want to find. This may sound obvious, but you are going to be searching a vast body of literature. There are over 20 million citations in the PubMed database alone and only a small proportion of these will be relevant to your topic. Unless you are very clear about what you want, retrieving these relevant items will be extremely difficult.

4. Ask questions… What do you want the literature to tell you?
Question x4 by Mike Coghlan Reproduced under a Creative Commons Licence
Turning our topic into a question is helpful because it forces us to think about what it is we really want to find. It is important that this question is focused. “How can maternity services be best delivered?” is too vague and ill-defined for an effective literature search. Think about how many potential papers this could retrieve. “Which are the most effective ways to deliver maternity services to rural populations in low-income countries” is much more appropriate. In this case we have defined our topic by thinking about a specific population and geographical setting.

5. Which are the most effective ways to deliver maternity services to rural populations in low-income countries?
Once you have developed a question you must identify the key concepts within it. Which concepts must every paper that you find address in order for it to be relevant to you? We will need to use these concepts when we come up with our search terms.
I have highlighted the concepts that make up my question in red. Everything I find must be about maternity services, rural populations and low-income countries. If any of these concepts are not represented in a paper then it will not be relevant to me and I don’t want to find it.

6. Which databases should I search?
PubMed/Medline
Biomedicine and clinical medicine
Embase
Biomedical and clinical medicine
Global Health
International public health
Africa-Wide Information
Information from or about Africa
Cochrane Library
Healthcare interventions
CINAHL
Nursing and allied health
Popline
Reproductive and sexual health
Web of Science
All academic disciplines, good for social sciences
ELDIS
Grey literature related to development issues
This is step 2 of the literature search process. The databases you choose depend very much on the search topic. Each database covers a different topic or type of information and you must choose the ones that are most appropriate for your search question.
LSHTM database subscriptions are grouped by topic on our web-pages You may be prompted to log-in with your Moodle username and password (begins with lon).
These are some popular databases used at the School. More information is available in this guide Find our complete database listing at

7. How do I identify appropriate search terms?
Choosing your search terms is step 3 of the literature search process. We will need to refer back to the concepts we came up with at step 1. A database is not cognitive, and it especially can’t understand nuances in language. If I search for maternity services the database will not know I also want to find papers that discuss maternity care or maternal health services. You need to think of all the ways each of your concepts could be described in the title or abstract of a paper. Spend some time generating this list of keywords, your results will only be as good as what you put in. Further information about indentifying search terms is available

8. Which are the most effective ways to deliver maternity services to rural populations in low-income countries?
Maternity Services
Maternal health service(s)
Maternal healthcare
Maternal health care
Maternal service(s)
Maternity care
Maternity service(s)
Postpartum care/service(s)
Postnatal care/service(s)
Prenatal care/service(s)
Antenatal care/service(s)
Rural populations
Rural community/ties
Rural population(s)
Remote population(s)
Remote community/ties
Non-urban
Villages
Low income countries
Developing country/countries
Developing nation(s)
Developing world
Low resource setting
LMIC(s)
Africa(n)
South East Asia(n)
South America(n)
Here are the keywords I came up with for each of the concepts in my maternity services question. Notice how I have considered different word endings such as plurals, the databases will not search for these automatically. You should also make sure you account for differences in UK and US spellings or terminology, and include the full name of any abbreviations.

9. What are subject headings?
You may also hear subject headings referred to as MeSH terms or thesaurus terms. When we search by subject heading we are not searching the terms the author has used in the title or the abstract, we are searching index terms that have been applied to each article to show what it is about. They work in much the same way as the index of a book. When we look up HIV in an index it tells us all the pages which have content about HIV. In a similar way, using the subject heading HIV will bring us all the items in a database about HIV – whether they have used the term HIV, HIV-1, HIV-2, human immunodeficiency virus or something else to describe that concept. Not every database uses subject headings, and those that do each use a different set of index terms. A comprehensive search will use both keywords and subject headings. A fuller explanation is available
This is a record from the Medline database. In the red box are the index terms that are applied to this record to show what the paper is about. It is these terms that you are searching when you search by subject heading.

10. How do I combine my search terms together?
We are now up to step 4 of the search process, compiling the search and running it in a database. This step is more completely explained here We have to input our search terms in a way that the databases understand so that they run the search in the way we want them to. Most importantly, we have to use Boolean operators to join our terms – AND & OR.

11. ( ______ OR ______ ) AND ( _____ OR _____ OR _____ )
Search 1
Search 2
AND means both – if you join terms with AND you will only find items in which those terms appear together. AND finds articles with all of our terms, so only the blue area of the diagram. We use AND to combine our searches for different concepts – we want to find papers discussing both maternity services AND rural communities.
OR means either – we join terms with OR when we want to find any of them. OR finds articles with one or more of our terms, so all of the blue areas in the diagram. We use OR to join our synonyms for the same concept – we want to find anything that discusses either maternity care OR maternal healthcare.
( ______ OR ______ ) AND ( _____ OR _____ OR _____ )
When we use AND & OR together in the same search line we need to use brackets to show the order in which we want our terms combined. They work in the same way as brackets in algebra, breaking up discrete and separate sections of the search.

12. You can run your search as one long search string, using brackets to separate the concepts…
("maternity services" OR "maternal health services" OR "postnatal care" OR "postpartum care") AND ("rural populations" OR "remote populations" OR "rural communities" OR "remote communities" OR non-urban OR villages) AND ("developing country” OR "low income country" OR africa OR "south america" OR "south east asia")

13. Or in many databases you can search for each concept separately, and then combine the individual searches together with AND at the end.
(matern* OR postnatal OR postpartum OR prenatal) and (care OR service*)
rural communit* OR remote communit* OR rural population* OR remote population* OR village* OR non-urban
developing countr* OR low-income OR africa* OR south america* OR south east asia*
1 AND 2 AND 3
I have used truncation in this search (*). Adding the truncation symbol to the root of a word will find all the possible word endings e.g. matern* will find both maternal and maternity. You can find more tricks like this to improve your search here

14. Concept 1 keyword search Concept 1 subject heading search 1 OR 2
For the most comprehensive search your strategy should combine both keyword and subject heading searching. The structure will look something like this:
(matern* OR postnatal OR postpartum OR prenatal) and (care OR service*)
exp Maternal Health Services/
1 OR 2
rural communit* OR remote communit* OR rural population* OR remote population* OR village* OR non-urban
exp Rural Health Services/ OR Rural Population/
5 OR 6
developing world OR africa* OR south america* OR south east asia*
exp Developing Countries/
7 OR 8
3 AND 6 AND 9
Concept 1 keyword search
Concept 1 subject heading search
1 OR 2
Concept 2 keyword search
Concept 2 subject heading search
4 OR 5
Concept 3 keyword search
Concept 3 subject heading search
7 OR 8
3 AND 6 AND 9

15. Why has my search not found what I need?
Don’t expect to put together a perfect search strategy first time. Searching is an iterative process and it often takes a couple of revisions before you have a strategy that is effective at finding what you want. First, look at the results you have retrieved. Most databases will highlight your search terms in the results so you can see why a particular item was returned. Use this to start your thinking about how the strategy could be improved.

16. Why has my search not found what I need?
Problem 1 – I can’t find any papers
Is the scope of your search too narrow? In this search, the strategy is very specific in that it only wants to find papers about Brazil. Expanding the focus to find potentially relevant material from other South American countries would retrieve more results.
Have you included all relevant keywords and subject headings? This search has not identified synonyms for each of the concepts. This means that papers using terminology other than that included in the search are not retrieved. The search would exclude anything where the author talks about “maternal transmission” or “vertical transmission”. You can use the terminology found in papers you have already identified to add to your list of terms.
Have you checked your spelling and use of syntax? Make sure you have not misspelt a crucial keyword, and you have used Boolean operators, truncation etc correctly.
Are you searching the most relevant database? Different databases contain different information, does the one you are using cover your topic area? The search above is from Medline, but perhaps Global Health and Popline would find more results as they focus on international public health and reproductive health respectively.

17. Why has my search not found what I need?
Problem 2 – I have too many irrelevant papers
Check your search terms, are they specific to the information you want to find? Often the same word can be used in many different contexts. In this search, nursing has been used as a synonmyn for breast-feeding which returned many irrelevant results about the nursing profession. In cases like these you will have to decide whether the term can be omitted from the search without loosing crucial papers.
Look out for where you have used very general terms in your search and replace these with what it is you really want to find. Participation is not a great search term as it could mean anything. Terms like “patient participation” or “community participation” are more specific and therefore more effective.

18. I’ve found some useful papers, now how do I get the full text?
This is step 5 of the literature search process, finding the full text.
There are 4 ways you can do this
Using the button from within the database. Find out how this works here
LSHTM Library catalogue
Using another Library – we can advise on schemes such as SCONUL Access ( and HINARI (
Request the material via our Document Delivery service

19. How can I best manage my references?
IT Services supports reference management software, rather than the Library. They have written guides to two freely available, web-based resources.
You can import references from most databases into these resources. The guides will take you through this.
Mendeley (
Zotero (

20. I still have some questions...
There is lots more information available on our web-pages including resources for more advanced searching.
Post a question to the Library Support Conferences on Moodle
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