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The Library: Nutrition & Dietetics

What is a Literature Review?

A literature review is a study of the existing literature, journal articles, books, reports and other information and evidence published on a given topic. It is a critical and evaluative account of any published work around a research field, including a description and analysis of existing knowledge of the topic, the identification of any gaps in the existing body of knowledge, and - where appropriate - an explanation of how your research might further develop current understanding of the subject. 

A literature review is not simply a description or summary of each individual paper. It should instead be structured around the findings of the articles considered, and is therefore an opportunity to identify common themes and issues as well as highlighting opposing arguments.

The Research Process

When you are given an assignment questions make sure you fully understand what is being asked on you. Refer to the guidance in your module handbook or lecture slides for further information, or discuss it with your tutors.

1. Identify the 'question' word(s)

You could use the 'Understanding Assignment Questions Worksheet' from the Essay Writing section of the Skills for Learning website to help you.

2. Identify core concepts/keywords

What is the main focus of the question?

3. Identify synonyms or related terms

Example:

Explore the impact of nutrition on patient recovery following surgery

'Explore' is the question word - it's what you have to do.

nutrition patient recovery surgery
nutrition* recovery operation
nutritional physical recovery surgical
diet enhanced recovery surgical procedure

On the next tab you will find tips and tricks to help you develop your search strategy and make your searching more efficient.

Once you have identifying your keywords, synonyms and related terms you can start to construct a search strategy.

4. Use search tools 

  • Phrase searching uses speech marks to help you search for phrases e.g. "surgical procedure" 
  • Truncation uses the asterisk to help you search for terms with variant endings e.g. nutri* = nurtrients, nutrient, nutritious, nutritional 

5. Combine terms using AND, OR and NOT 

  • AND - for combining different concepts
  • OR - for identifying research that use synonyms or related terms. You need to put the similar terms in brackets. 
  • NOT - use when you want to exclude a term (use with caution as it can eliminate useful results too)

nutri* AND ("post operative" OR "post surgery" OR "surgical procedure" OR operation) AND (recovery OR wellness)

Some resources have an 'advanced search' feature which can help you to combine your searches.

Remember!! Keep a record of your searches

Conducting a literature review involves a LOT of searching and reading. It is therefore important to keep a record of what searching you have done and where. It is recommended that you keep a searching log. Make a note of:

  • which databases you have searched 
  • what terms you have used as well as any searching techniques such as truncation
  • any limits you have applied e.g. date or geography
  • how many results you retrieved
  • how many of the results were relevant

You may wish to keep a record using a document such as the Search Log here. Check with your tutor whether this would be suitable to include in your Appendix. Think of it as a paper trail of your searching or even as a set of instructions for whoever is marking your work.

The PRISMA flow diagram may also be useful to guide you through the searching process as it can be used to highlight the number of records identified, included and excluded, and the reasons for exclusions.

6. Identify appropriate resources to search

   a. Reading lists - are there any core textbooks that your tutors recommend on your topic?

        Check your modules in MyBeckett

   b. Use Discover to find additional books and eBooks

   c. Use Discover to search our ejournals and other subscriptions

   d. Use databases to help you focus your results - available on the 'Databases' page of this guide

You can search most databases in exactly the same way, the search screen may just look a bit different.

To help you refine your results and make them more manageable look for limiters such as 'Publication date' or 'Resource type'.

The majority of Health and Social Sciences articles are written following the IMRAD format:

Introduction, Method, Research, And Discussion

Here are a series of points to consider for each section of such articles when appraising them:

Introduction: Why has the research been undertaken? What was the purpose of the research? The aims of the research should be clearly outlined in the introduction and should also contain any evidence of a literature review along with any keywords used by the author when searching.

Method: When, where and how was the study conducted? Who or what was the subject of the study? Are any ethical issues outlined? Was a pilot study conducted to identify any potential problems with the methodology? Is the information provided detailed enough for others to replicate the research? Has the researcher chosen a qualitative or a quantitative approach to data collection? If so, what are the strengths and weaknesses of each approach for this specific research? Is there any evidence of triangulation - of data being obtained by more than one method? Was data gathered from a large and diverse enough sample size? And how effective was the response rate or other collection method? Have any potential biases or issues been acknowledged? Have any interventions been made to eliminate any potential biases or issues which might have affected the research's reliability?

Results: Are the results comprehensibly presented? How do they relate to the original research question? Have the results - and the research's interpretation of them - been assessed by a peer-reviewer or other form of critical friend beyond the original researcher(s)?

Discussion: What are the practical, academic, professional and broader implications of the research? Is any of it applicable to your research, daily role, or professional practice? Has the researcher included discussion of how their study might be improved and suggestions for further study? What is your interpretation of this information?

Not all of the above points will apply to every paper, but at least some of them should help you assess the strengths, weaknesses and relevance of information that you are considering.

 

For more information about referencing, including the full Leeds Beckett Harvard guide - please visit our Referencing & Plagiarism pages.

Conducting a Systematic Review

As part of your final year project or dissertation, you may have to conduct a Systematic Literature Review (SR). If you have searched the Cochrane Library for Systematic Reviews, you will know that these are lengthy pieces of research, often taking years to complete and involving several researchers, which combine literature and research around a given subject. Due to time restrictions, the SR which you produce will not need to be as lengthy or as in-depth, so please do discuss with your supervisor what they expect of your SR.

The key to conducting a good SR is to start with a good research question. Before starting the SR properly, conduct a scoping review of the literature around your chosen subject to ensure there is enough literature available for you to discuss in your work. You can also use this stage of your SR to identify commonly used keywords or alternative search terms for your subject. Start by searching broadly and simply and use this time to identify gaps in the literature or areas where further research is needed which you may wish to focus on as part of your dissertation.

Many health students use PICO to formulate a good research question. Using PICO, your research question should contain 4 main elements, e.g.

  • Population (which group of the population do you wish to discuss), e.g. Amongst elderly adults who experience repeated falls......
  • Intervention (what treatment you are considering investigating), e.g..... does the intervention of a multidisciplinary team of health care professionals......
  • Comparison (this may be an alternative intervention if available), e.g. ......as opposed to relying solely upon the services of one team.....(please note, not all research questions have a comparison element).
  • Outcome (what are you trying to achieve or investigate), e.g. ......lead to falls reduction.....

It is important to clearly define each of the main elements of your research question as this will help establish your inclusion and exclusion criteria. Also, think about restricting your search to a specific time period or geographical location. Finally, check Cochrane and Prospero to ensure a systematic review has not been conducted previously in your area.

Don't rely solely upon Discover to conduct your SR. It is important to search several sources and databases. By conducting a SR properly using your search terms and several databases, you are showing your supervisor that you have advanced research skills. In addition, in the workplace, you will be expected to keep up to date with current research by using other resources such as PubMed, Nice Evidence, TRIP, so this is a good opportunity to familiarize yourself with these which are used in professional practice.

To find a list of other databases, go to the 'Databases' tab of this subject guide or go to our A-Z list of databases.

Once you have formulated your research question and identified alternative search terms/ synonyms, think about how you can combine your search terms. In many databases, the advanced search function enables you to do this easily. Remember to start searching broadly, then narrow you search using more specific terms. You can join the key concepts of your dissertation using AND to narrow and focus your search. If you do not retrieve enough literature, you can broaden your results by joining terms with OR. You can use NOT to eliminate any irrelevant search terms from your results. For example:

(Elderly OR Age*) AND ("falls management" OR "falls prevention") AND ("multi-disciplinary teams OR interdisciplinary teams OR multidisciplinary teams")

Consider different spellings of words e.g. organization / organisation, time restrictions, and geographical limitations to make your results more focused. You may also wish to consider narrowing your search to a specific type of research method.

Also, consider how you can use truncation to search for various different endings of words e.g. child* will search for childhood, childlike, childish, children.

You may have to perform several searches to retrieve the results suitable for you, and then transfer your searches into several other databases so make sure you keep a record of the searches you have performed even if none of the results are relevant. Remember, searching is a lengthy trial and error process.

Within CINAHL and MEDLINE you can use MeSH (Medical Subject Headings) to help you refine your search:

It is essential to write up ALL searches you perform as part of conducting your SR. Best practice is to record the date, database, search terms, limitations, number of results in total, then number of irrelevant results with a general statement as to why others have been discarded. This information can then be used as evidence (even put in the appendix at the back of your dissertation) that your searching has been thorough. You can record your searches using a simple template (see below), or register with individual databases which allow you to retain your search history.

Sample search history template, showing databases and search terms used

As part of your SR you may find that you retrieve lots of relevant articles and resources. Various different programmes such as Mendeley and EndNote allow you to store, make notes, and organise your references.

Now that you have found relevant research articles, it is a case of reading them carefully to identify key themes and arguments. Initially, decide whether an article will be useful by reading the title and the abstract and decide whether it meets your inclusion and exclusion criteria.

Once you have identified the most relevant papers, you need to assess the quality of the studies. You can use tools such as the Critical Appraisal Skills Programme (CASP) or the Scottish Intercollegiate Guideline Network (SIGN) to help you with this process. You might also want to look at the information above on evaluating information for more prompts and questions to ask of any research paper you wish to include.

Below you will find links to information which will help with critical appraisal.

Your Academic Librarians are available to help you with these stages of performing a Systematic Literature Review. You can find details of how to contact us on this page.

For more general help, please contact the 24-hour telephone and chat support using the Contact Us pages.