How to find information for science or health based literature reviews

You will be reading a lot of literature.

You may be tempted to skim some of the literature but we strongly recommend engaging and read fully all the relevant literature. Stay active when reading - make notes and evaluate the content as you read!

 Activity 1: Watch this video to remind yourself why critical reading is important. 

Check your assignment brief, assessment grid or marking scheme to make sure you understand how in depth your literature review needs to be!

Thoughts to consider!

• If your assignment is purely just a literature review then all your words will be allocated to reviewing literature.

• If your literature review is only one part of your assignment, the amount of words you allocate to the review will need to be appropriate to make sure you can cover all the other aspects of your assignment.

• The word count set for the assignment will impact on how detailed your review can be. A literature review with a 3000 word count will not be able to go into as much depth as a literature review that has a word count of 10,000 words.

• Your literature review is bound by your word count! Be mindful and select the most robust and appropriate evidence.

We have chosen three articles from our searches to show how primary and secondary articles may present a literature review.

We have chosen one two secondary articles to show you how detailed a literature review in secondary sources can be and how it can be reported or discussed,

• One article is an original research article also know as a primary source.

• One article is a review article also know as a secondary source.

• One article is a systematic review also know as a secondary source.

If you need a refresher about what is a primary or a secondary source, we have provided an explanation below. 

What is a primary article?

A primary article is an article which is testing an idea, doing an original piece of research and using literature to support the article ideas. 

• A primary article is when the authors have done the work they are writing about.

What is a secondary article?

A secondary article is an article which poses a question. The answer to the question is found by searching the literature and using existing research and evidence to arrive at an answer to the question based on the balance of evidence found from researching. 

• A secondary article is when the authors are basing their discussions on  on other peoples work

You can find the answer in the Answer box at the end of the page.

Research gaps are areas of uncertainty, where knowledge is not fixed... a space where there are research questions still to be posed and areas investigated.

Research gaps can cause challenges as there may not be enough literature to review for you to be able to pose the research question that appeals to you.

You are likely to find if there is enough literature for you to review when you have completed running your scoping searches. 

Scoping searches using PubMed and the Cochrane Library found the following articles with a range of findings and perspectives related to honey or silver and topical wounds.

There are differing conclusions within these articles... which means there is a research gap that we can work with and base our literature review within!

• Jull, A., Cullum, N., Dumville, J., Westby, M., Deshpande, S., & Walker, N. (2015). Honey as a topical treatment for wounds. The Cochrane Database of Systematic Reviews, 2015(3), CD005083. https://doi.org/10.1002/14651858.CD005083.pub4

• Benjamin A. Minden-Birkenmaier, & Gary L. Bowlin. (2018). Honey-Based Templates in Wound Healing and Tissue Engineering. Bioengineering, 5(2). https://doi.org/10.3390/bioengineering5020046

• Rodriguez-Arguello, J., Lienhard, K., Patel, P., Geransar, R., Somayaji, R., Parsons, L., … Ho, C. (2018). A Scoping Review of the Use of Silver-impregnated Dressings for the Treatment of Chronic Wounds. Ostomy/wound Management, 64(3), 14–31. https://doi.org/10.25270/owm.2018.3.14.

• Naik, K., & Kowshik, M. (2017). The silver lining: towards the responsible and limited usage of silver. Journal of Applied Microbiology, 123(5), 1068–1087. https://doi.org/10.1111/jam.13525

• Stormversloot, M., Vos, C., Ubbink, D., & Vermeulen, H. (2010). Topical silver for preventing wound infection. Cochrane Wounds Group, (3), CD006478. https://doi.org/10.1002/14651858.CD006478.pub2

• Saikaly, S., & Khachemoune, A. (2017). Honey and Wound Healing: An Update. American Journal of Clinical Dermatology, 18(2), 237–251. https://doi.org/10.1007/s40257-016-0247-8

• Punjataewakupt, A., Napavichayanun, S., & Aramwit, P. (2019). The downside of antimicrobial agents for wound healing. European Journal of Clinical Microbiology & Infectious Diseases, 38(1), 39–54. https://doi.org/10.1007/s10096-018-3393-5

It is not enough to find information.

You need to make sure you find the most appropriate, relevant and reliable information to fulfil your literature review assignment. You need to evaluate the information and sources you use and make sure out of the millions pieces of information you could have used... you used the best possible pieces!

Here is a list of commonly used criteria for evaluating information: 

The authority and credibility of the source.

• What does the author know about the subject?
• What is their background? 
• What else have they written?

Bias.

• Could the source or author have any bias (conditional or unconditional)?
• Is the source trying to sell you something, or push a certain political or ideological stance?
• Is it misrepresenting the evidence, or omitting evidence which you know exists elsewhere, or even not presenting any evidence at all for its claims?
• Have you considered the international perspective?
• Are there any geographical bias in searches or source selection?
• Ideally, you want balanced, neutral sources which considered all the available evidence. 

The relevance of the source material.

• Even if the source turned up in your search results, is it actually about what you want to know?
• Is it only tangentially connected to your topic, or on another subject all together?

The age of the source.

• How much has changed since the source was published?
• Have any later developments contradicted or overturned what the source argues?​
• Be mindful of using date to exclude a journal paper. Some papers are classic papers e.g. when a specific method was first published and a literature review may be incomplete if that specific paper was not included in a review.

This section comes with a large warning before you consider applying these ideas to your literature review!

• If you are a student in the Department of Bioscience and Chemistry, it is unlikely that this information applies to your literature reviews.
• If you are a student in the Department of Allied Health Professions and Nursing, this information may be of use for your literature review.

If you plan to apply these approaches, we recommend you check your assignment outline to confirm that they are required. If you are in any doubt, check before you do this!

Some literature reviews, particularly within - but not exclusive to - Health-related subjects, use specialist evaluation criteria which then leads into search write-ups. You may also be encouraged to set exclusion and inclusion criteria, or describe your search strategy. The use of specialist criteria depends on your subject area, and the exact requirements of your assignment.

 Activity 2: If you are unsure what you need to do and how complex your literature review should be and whether you need to use specialist screening or evaluation tools... check with the with the person that set your literature review that they are actually required before you start using them.

It is admirable to want to do the best literature review you can, but stay within your literature review brief!

What to do if If you have been asked to use PICO to describe your search strategy.

The PICO technique is commonly used for finding quantitative research articles. These resources show you how to use it to describe your search strategy.

However, if you find your topic requires you to find qualitative or mixed-methods research (for instance, you do not have an intervention), you may want to use the SPIDER technique:

PRISMA Flow Diagram.

A PRISMA flow diagram details your search strategy and inclusion and exclusion criteria.

What to do if you have been asked to use a PRISMA flow diagram or if you have been asked to create a PRISMA flow diagram to show where you have found your evidence...

Check with your tutor that you need to do this before you start as this is a very detailed piece of work!

It is also a really, really good idea to keep a record of how you have found your evidence and literature! You can do this in a simple table, noting where you have searched, your terms, inclusion/exclusion criteria, filters and number of results.

These links guide you through creating your PRISMA Flow Diagram:

What to do if you have been recommended to use specialist evaluation criteria.

You may be asked to use specific evaluation tools or be given guidance by your tutors on which method to use. Always check with your module documents or tutor if you are unsure! 

Here are examples of the most commonly used specialist evaluation tools:

Screening protocols - for example looking at title and abstract first, then full text when you have whittled out studies from the first screening. You may need to agree this with your supervisor, so always check!

If you have been asked to use inclusion/exclusion criteria.

Some literature reviews use simple exclusion criteria to screen out information.

• A date limit can be useful due to volume of material or the review being time bound.
• A specific population type, intervention, outcomes and data. This is to ensure the specific type of information is found by the search strategy and kept within the search scope.

If you need to choose inclusion or exclusion criteria more complex than above, we recommend you contact the person that set the assignment for advice.

Some of the literature review books may refer to systematic reviews which include very detailed search strategies, inclusion and exclusion criteria and screening tools.

Do not confuse a systematic review with a literature review!

You can systematically review literature and you may decide to use some of the search techniques you see listed in literature review books that cover systematic reviews. 

A systematic review is a specific piece of research that does not commonly feature as a student assignment.

Honey and Wound Healing: An update... is a review article and a secondary source.

Honey dilution impact on in vitro wound healing: Normoxic and hypoxic condition: Honey dilution in hypoxic wound healing is an original research article and a primary source.

Honey as a topical treatment for wounds is a systematic review and a secondary source.

Congratulations you have completed the sixth step.

Time to take a break - maybe take some inspiration from another person you admire! Take a look at these inspiration people and their narratives, biographies, autobiographies or experiences.