Siobhán McCoy. Navigating the Sea of Clinical Literature, Don't Forget the Bubbles, 2018. Available at:
“If we choose to change nothing, then nothing will change”
I started with this because, there is no two ways about it, clinical research can be hard. 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 have to choose to change them. So, lets 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 important to have an idea of what is going on within your chosen speciality in relation to developments in clinical practice, policy and education. Although the wonderful world of FOAMed helps us to generate a broader view, it does not cater for 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 am going to look at how we navigate the literature as part of a literature review. In the last post, we reviewed the process of 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 which the review is intended
Why do we do literature reviews?
A literature review:
- Provides a background on what is already known about your chosen topic
- Places your proposed research within the context of your chosen field
- Presents your analysis, interpretation and synthesis of the existing literature
Ok, time to get cracking! – 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?
- One of the key elements is manageability. 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 right studies is a critical element to a successful literature review. This requires you to embark on the dreaded search. The ever-familiar feeling of drowning in the literature is one we can all relate too. So, here are a few tips to keeping your head above water.
- Examine your resources, 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 would not scrub up to undertake cardiothoracic surgery, would you? This is a similar situation with obviously less significant repercussions.
- Make a list of search terms related to the topic and the research question
- Get a colleague/supervisor to check these, they may identify terms you have missed or did not think of
- Remember some terms will have different spellings, depending on the study’s country origin, for example: Paediatric in Europe is Pediatric in the USA. Simple but crucial
- Once you have established these terms make sure to keep a record of same. This will save time going forward
- Databases – this is where you will find the bulk of the literature
- 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 conduct 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 as a whole 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 a number of ways to reduce the chance of this happening:
- Be thorough and remember the focus of the review
- Develop an eligibility criteria for studies you deem fit for inclusion in your review
- Read study abstracts carefully
- Once you have identified your eligible paper/studies there is a secondary search which should be completed. This involves:
- Looking at reference lists of eligible studies/reviews earmarked for your review. This process could highlight studies you have overlooked
- 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 key papers could have an effect on 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:
- An interpretation of the literature by actively participating in the review and rationalising your opinion
- Synthesising the literature – this is a process of 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 quite intense and can often be hampered by the reviewer becoming overwhelmed and losing focus. Following 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 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 critical 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 wider community.
A comprehensive review, like any research study, 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 just remember…
If we choose to change nothing, then nothing will change
There is one final thing I would ask every author to do before you press the save button and this is where you must be entirely honest with yourself. Does this review answer our central research question? The answer and the actions you take related to this question are 100% up to you.