Clinical research can be challenging. It’s not the new Gucci piece of kit everyone wants to use, but it is the foundation of healthcare as we know it. If we want things to change, we must choose to change them. So, let’s dive into our next instalment of the DFTB research section.
Healthcare literature is evolving at a rate of knots and it can be hard to keep up. The sheer volume of literature out there is, for want of a better word, baffling. Although you are not expected to have read it all, it is essential to know what is going on within your chosen speciality about clinical practice, policy and education developments. Although the wonderful world of FOAMed helps us to generate a broader view, it only caters to some of the nuances of your specific research question. This is where it is your job to dig a little deeper.
So, like others who have come before me, today I am going to wander through the quagmire that is the medical literature. In particular, I will look at how we navigate the literature as part of a literature review. In the last post, we reviewed establishing your research topic and generating that all-important research question. The literature review is the next logical step in the generation of your study design, funding proposal or trial protocol and a critical element in any funding application.
First things first, every literature review should be guided by a central research question for three reasons:
- It establishes boundaries for the reviewer
- It keeps the review focused
- It defines the topic and audience for the review
Why do we perform a literature review?
A literature review:
- Provides background on what is already known
- Places your proposed research within the context of your chosen field
- Presents your analysis, interpretation and synthesis of the existing literature
Top tips for literature reviews
- Define the topic AND the intended audience
- The topic has to interest you, otherwise you have made your job ten times harder before you even start
- It should be clinically relevant – be sure to ask the question, has it been done before?
- There should be a balance. If a review is too broad or too narrow, it can cause significant issues for the reviewer; striking this balance can be difficult.
- Finally, the more obscure your topic the harder the review will be
Conducting the review
Finding the proper studies is a critical element of a successful literature review. This requires that you go ahead and start the dreaded search. We can all relate to the ever-familiar feeling of drowning in the literature. So, here are a few tips for keeping your head above water.
Who can help you?
Your supervisor or colleagues.
An information librarian (they do this as part of their job)
And remember, it is not cheating or ethically questionable to enlist the skills of a specialist. If you’re a dermatologist, you wouldn’t scrub in to undertake cardiothoracic surgery, would you? This is a similar situation with obviously less significant repercussions.
Make a list of search terms
Get a colleague/supervisor to check these; they may identify terms you have missed.
Remember, some terms will have different spellings, depending on the study’s country of origin; for example, Paediatric in Europe is Pediatric in the USA. Simple but crucial.
Once you have established these terms, keep a record of the same. This will save time in the future
You will use multiple databases. However, they should be relevant to the topic of interest. For example: If you are conducting a study on the use of pre-hospital TXA in stroke patients, you will not perform a search in PsycINFO or PEDro.
Keep a record of the search which yielded the most relevant results, as you can copy and paste it across multiple databases.
Your searches could result in thousands of studies; this is the point at which some researchers lose their way. This is because you’re afraid of excluding that one seminal paper which in turn voids all your hard work. Be not afraid, my friends; there are several ways to reduce the chance of this happening:
Be thorough and remember the focus of the review.
Develop eligibility criteria for studies you deem fit for inclusion.
Read study abstracts carefully
Once you have identified your eligible paper/studies, a secondary search should be completed. This involves:
Looking at reference lists of eligible studies/reviews earmarked for your review. This process could highlight studies you need to look into.
Also, to circumvent a massive meltdown due to the sheer volume of studies to review now is the time to enlist the help of a citation manager such as EndNote or Papers
And don’t forget the importance of seminal papers/research, as they will always have a place. Dismissal of these critical papers could affect the validity of your review as a whole
Now you have identified the studies for the review; it’s time for the hard part, the term that strikes fear into the hearts of all researchers – the critical appraisal of the literature.
Evaluating and analysing the data
Critical appraisal is not just summarising the literature. As a researcher, you are expected to offer your readers the following:
- An interpretation of the literature by actively participating in the review and rationalising your opinion
- Synthesising the literature is a structured critique of the relevant work and your coherent argument of the existing literature and how it relates to your study. This process creates an integrated whole for the reader.
This part of the review can be pretty intense and can often be hampered by the reviewer becoming overwhelmed and losing focus. A structured, systematic approach to critical appraisal can prevent the researcher from meandering off-course.
There are a number of critical appraisal tools which will facilitate this process:
- BestBETs CA Worksheets – https://bestbets.org/links/BET-CA-worksheets.php
- CASP Checklists – https://www.casp-uk.net/casp-tools-checklists
- Centre for Evidence-Based Medicine – https://www.cebm.net/blog/2014/06/10/critical-appraisal/
Writing the literature review
How you present your review will very much depend on your own personal writing style. There should be a systematic structure to the delivery and the discussion supporting this argument, and it should be engaging for the reader. Presenting a critical appraisal of the literature can be a fine line to walk professionally. Just because it is a critical appraisal does not give you a licence to be overtly essential though nobody wants to read a review that presents the literature but does not offer any valid interpretations. It is your job to strike that balance being as objective as possible and offering a coherent synthesis of the literature which will be beneficial to the broader community.
Like any research study, a comprehensive review will have highs and lows. But it is the hard graft that you put in that will make it worth it. So, when you are sitting in front of your computer agonising over your interpretations of the literature, remember…
There is one final thing I ask every author to do before you press the save button, and this is where you must be entirely honest with yourself. Do you think this review answers our central research question? The answer and the actions you take related to this question are 100% up to you.