Top LitReview Systematic Screening
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“There is no 'perfect' number of papers to include in your systematic review. If your searching, screening and selection processes have been sufficiently rigorous, then you should feel confident that you have identified all relevant evidence”
Once you've conducted your search you will be ready to screen your results against your inclusion and exclusion criteria in order to determine their eligibility for the review. You can then extract your data, summarise and discuss your findings and make your conclusions.
Screening and selection
Step one:
Firstly you need to de-duplicate your total results set. Some databases such as EbscoHost will remove these automatically for you, but if you are using a variety of search platforms you will need to export to reference management software to remove the duplicates.
Step two:
The next stage is to screen the titles and abstracts of the papers for relevance, also using your inclusion and exclusion criteria. It is good practice to place these into a folder if the database has that option (such as EbscoHost), if not you can export to reference management software. RefWorks or EndNote allow you to export citation information from databases and organise the articles in folders around themes before exporting them to your documents saving you a lot of work typing, copying and pasting.
For anything other than an undergraduate review, there should ideally be at least two people screening the results to avoid bias. However, time and resource may necessitate that this is not possible.
Step three:
Next you should try and obtain the full text of the selected papers. If the University does not have a subscription then you may need to use the Interlibrary loan service. Contacting the authors or trying to locate a legal version via Google or networks such as Academia.edu or ResearchGate.net is another option.
Step four:
Finally you need to decide whether these full text papers definitely meet your inclusion criteria. If you decide to exclude then make a note of the reasons why as you may need to document this further down the line.
The results of the screening and selection exercise should be reported in your methods section and the PRISMA flow diagram can be used to document these decisions.
Extracting relevant information
Once you have identified the papers to include, you need to recognise and then extract relevant data from each individual study. You can then create relevant extraction tables which might be in the form of a summary table or synthesis matrix - see our page on The process of reviewing for examples of these.
The data you might extract includes: authors & publication year; study design; number of participants; interventions; and study outcomes.
You may use data analysis tools such as NVivo and SPSS to extract and analyse data depending on the study type.
Deciding on quality
Once you've extracted the data it's important to examine the quality of the studies. You need to assess whether the studies have been designed, conducted and reported in a way that they can be considered as reliable (rigour) and whether they provide meaningful answers to your research questions (relevance).
There are many tools available for you to use. The Critical Appraisal Skills Programme (CASP) at the Centre for Evidence Based Medicine (CEBM) in Oxford has produced a number of appraisal tools for use when appraising different types of study. CASP offers a set of 8 critical appraisal checklists which can be used for study types such as systematic reviews, randomised controlled trials and qualitative studies:
CEBM also provides this further set of Critical Appraisal Guides.
Our page on The process of reviewing also has some advice on evaluating a source's worth and usefulness to your study.
Discussing and summarising findings
The discussion section of your review should provide a critical interpretation of the results in relation to the review question that you set out to answer. If these sections don't reflect the nature and limitations of the research process and the evidence you have presented, then you have not appropriately addressed the research question. The main components include:
What are the main findings?
How do they fit with previously published research?
What are the strengths and limitations of the included studies?
Can the findings be generalised?
What are the implications of the review?
What conclusions can be drawn from the review?
Useful books and eBooks from our collection
How to Read a Paper [eBook] by
Required reading in many medical and healthcare institutions, How to Read a Paper is a clear and wide-ranging introduction to evidence-based medicine and healthcare, helping readers to understand its central principles, critically evaluate published data, and implement the results in practical settings. Author Trisha Greenhalgh guides readers through each fundamental step of inquiry, from searching the literature to assessing methodological quality and appraising statistics. How to Read a Paper addresses the common criticisms of evidence-based healthcare, dispelling many of its myths and misconceptions, while providing a pragmatic framework for testing the validity of healthcare literature. Now in its sixth edition, this informative text includes new and expanded discussions of study bias, political interference in published reports, medical statistics, big data and more. Offers user-friendly guidance on evidence-based healthcare that is applicable to both experienced and novice readers Authored by an internationally recognised practitioner and researcher in evidence-based healthcare and primary care Includes updated references, additional figures, improved checklists and more How to Read a Paper is an ideal resource for healthcare students, practitioners and anyone seeking an accessible introduction to evidence-based healthcare.
ISBN: 9781119484738Publication Date: 2019
Doing a Systematic Review [print book] by
Written in a friendly, accessible style by an expert team of authors with years of experience in both conducting and supervising systematic reviews, this is the perfect guide to using systematic review methodology in a research project.
ISBN: 9781473967007Publication Date: 2017
Comprehensive Systematic Review for Advanced Nursing Practice [eBook] by
This book comprehensively and concisely examines the complexities related to asking clinical questions, searching for the evidence, appraising and summarizing the evidence, and getting evidence into practice.
ISBN: 9780826131867Publication Date: 2017
How to Do a Systematic Literature Review in Nursing [eBook] by
A step-by-step guide to doing a literature review in nursing, or related healthcare professions, that takes you through every step of the process from start to finish.
ISBN: 9780335242283Publication Date: 2012
Systematic Reviews to Support Evidence-Based Medicine [print book] by
This book simplifies and explains the key steps involved in reviewing literature. Written in a concise and easy-to-digest form, and avoiding technical jargon, Systematic Reviews to Support Evidence-based Medicine remains a must-read for all healthcare professionals.
ISBN: 9781853157943Publication Date: 2011
