Hello! For today’s blog I am going to provide a guide on how to go about your first literature review. I know, sounds super daunting. But as someone that is now 2 years into their PhD, and 4 years into their research career – I can tell you that with the right tools and a focused approach, your literature review need not be a frightening task. So here it is, my complete guide to smashing out your literature review.
First things first, WHAT is a literature review? A literature review is a critical recap of what has already been researched on a topic. This could include any source such as books and published journal articles, but also may include other materials known as “grey literature” – for example, reports, working papers and government documents.
And WHY do a literature review? Literature reviewing is more than just a checkbox exercise. In enables you to find out what’s already known about your topic, and how other researchers have approached it. As well as setting the scene for the rest of research, by giving your reader a critical overview of what you have found regarding the existing knowledge, and how your research topic fits in. Finally, conducting a literature review allows you to find out if there are any research gaps so that you may contribute something novel and original to the field. This step minimises replication of methods and ideas.
In order to initiate your literature review, you firstly need to identify your research question. There are several tools that you can use to establish a well-formulated research question. In evidence-based clinical practice, the PICO format is typically used whereby: P, indicates the patient/ population; I, indicates the intervention; C, is for the comparator (if there is one) and O, stands for the outcome(s) of interest. For example:
Question formats are a helpful tool for researchers that just help to structure the research question and enable a focused search. There are several other formats, linked below.
Next, you need to decide on the scope for your review. By this, I mean how comprehensive does your search need to do? This will depend on the requirements of your assignment, and the type of literature review you are conducting. If you are conducting a systematic review, this is considered as a comprehensive review and should be understood as a stand-alone work. There is not infinite time and resource to search and appraise every single relevant record out there, so you may decide for example, that you will only look for studies covering the last 20 years.
So now you’ve refined your topic and scope, you need to get started on conducting your search. This involves using scholarly databases like google scholar or PubMed. For a preliminary literature review, I wouldn’t worry too much about searching multiple databases, so stick to whichever you find easiest to use. You’ll need to conduct a search including your key words with Boolean operators to help you filter and refine your search results. You may want to include MeSH (medical subject headings) terms – which are standardised keywords that you can look up in the MeSH database. These enable you to capture an entire set of literature using a single term. Make sure you keep a record of the searches that you conducted, and the dates too. You may want to duplicate these at a later date, or you may want to re-run them with different timepoints to find newly published evidence. An example of how to use Boolean operators is here below:
Next, you’ll want to save and export your search hits. Make sure you keep track of your citations; I find it easiest to do this by using a citation management software such as EndNote or RefWorks. Then, I like to export my hits directly into an excel spreadsheet. I find it’s easier to select materials and keep track this way.
So you’ve got your hits – now it’s the selection stage. Depending on your topic area, you’re probably going to have generated a very large number of hits – some of which will not be relevant to your research question at all. You can eliminate articles at this stage by screening titles, and if you need further detail the abstracts, to identify the articles relevant to your work.
Now you’re ready to read! As you read though, be sure to take notes and pay close attention to the common themes between sources. Without some sort of structure, this step can be tedious and could involve reading the same sources multiple times. One way to go about organising this is to develop a table with key headings related to the information that you will want to later discuss in your write-up. This could include for example, the methodology the authors used, underlying theories, or information related to the population sample. Being organised at this stage will help you to establish patterns or connections between the different sources, helping to formulate an interesting argument for your review. An example of how to organise this step is here:
Finally – get writing! Make sure that your literature review has an introduction – which will provide the background and rationale behind the review. Followed by a main body, where you can summarise and synthesise the sources. Remember, a literature review is a critique of the existing evidence – not just recall. You may want to use an assessment checklist to help guide your critical analysis, for example in health economics we have the CHEERS checklist. Then you’ll need a conclusion – just like other academic works, where you draw in the key themes and indicate the gaps in the research that you have found.
And there you have – a complete guide to conducting a literature review! I hope that you found this useful. Oh and a final and kinda obvious tip – always remember to proof read your work before you submit it!
Thanks for listening, Hannah!
Hannah Hussain  is a PhD Student in Health Economics at The University of Sheffield. As a proud third generation migrant and British-Asian, her career path has been linear and ever evolving, originally qualifying as a Pharmacist in Nottingham, then Health Economics in Birmingham. Her studies have opened a world into Psychology, Mental Health and other areas of health, and with that and personal influences she found her passion for dementia.