Critical Appraisal
Critical appraisal is the process of systematically examining research evidence to assess its validity, results and relevance before using it to inform your decision making. This guide aims to introduce you to the process and the tools used to appraise different types of paper.
Critical appraisal is an essential part of evidence based practice. It is a holistic process which helps practitioners decide whether a piece of research is good enough to be used in decision making. It is about evaluating the whole research process, rather taking the results at face value.
To help you undertake critical appraisal, several user-friendly tools are available. These are usually in the form of checklists and many of them are freely available online. These checklists will prompt you to ask appropriate questions when reading a paper and help you to maintain an objective view of the research. See below for more details about critical appraisal check-lists.
Critical appraisal is an essential part of evidence based practice. It is a holistic process which helps practitioners decide whether a piece of research is good enough to be used in decision making. It is about evaluating the whole research process, rather taking the results at face value.
To help you undertake critical appraisal, several user-friendly tools are available. These are usually in the form of checklists and many of them are freely available online. These checklists will prompt you to ask appropriate questions when reading a paper and help you to maintain an objective view of the research. See below for more details about critical appraisal check-lists.
Our training session:
We offer critical appraisal training which can be tailored for your specific needs. Our training session 'Interpreting the Evidence: An Introduction to Critical Appraisal will introduce you to principles of critical appraisal and why it is important to evaluate evidence. It covers how to consider the quality, results and local applicability by using a checklist on a relevant example of research. We also support journal clubs within departments and can help you to set up a journal club, find evidence for you to review and can attend to guide the discussion.
Contact us to book a training session (01709 427139 rgh-tr.libraryhealthcare@nhs.net): we can deliver training in one of our study spaces, in your department or online. Please contact us for further details.
Contact us to book a training session (01709 427139 rgh-tr.libraryhealthcare@nhs.net): we can deliver training in one of our study spaces, in your department or online. Please contact us for further details.
Online support materials:
- Critical Appraisal from Kings College London
Includes a list of important texts on critical appraisal and medical statistics. These are also links to websites covering these subjects as well as checklists and sources on qualitative and quantitative research. https://libguides.kcl.ac.uk/NHS/CAS - Joanna Briggs Institute Resources and Publications
The JBI has a collection of resources to support evidence based practice particularly systematic reviews. It features critical appraisal checklists and advice for putting evidence into clinical practice. https://joannabriggs.org/ebp - Cambridge University Medical Library:
Online resources to support critical appraisal: https://library.medschl.cam.ac.uk/critical-appraisal-resources/
|
Reading a paper
When approaching a paper, there are several things to consider. Look at the extrinsic factors. These are factors not related directly to the study itself, but which may have some influence on it. Ask questions like:
|
|
|
Intrinsic factors are all factors relating to the study itself. Consider issues such as:
|
A good paper will be divided into sections. This will help you to locate relevant pieces of information in order to answer your questions.
For example:
For example:
- Is it of interest? - the title and abstract should give you enough information to decide whether a paper is of interest
- Why was it done? - the introduction will give you the background, the context and maybe some information about previous research
- How was it done? - the methodology will go into detail about how the study was undertaken
- What has it found? - the results section should go into detail about the results and their meaning
- What are the implications? - the discussion section will consider the implications and whether any further study is required
Critical appraisal tools
There are standard critical appraisal questions. These relate to the validity, results and relevance of the research. Whichever type of check-list you choose to use, the questions you ask will revolve around these three issues. While check-lists will ask questions in slightly different ways, they will cover the same ground. The questions you ask, and therefore the check-list you use, will depend on what kind of study is being reported.
There are several checklists available from different sources:
More detailed information about how to read different papers can be found at:
Other useful information about types of study and their relative value can be found at:
There are standard critical appraisal questions. These relate to the validity, results and relevance of the research. Whichever type of check-list you choose to use, the questions you ask will revolve around these three issues. While check-lists will ask questions in slightly different ways, they will cover the same ground. The questions you ask, and therefore the check-list you use, will depend on what kind of study is being reported.
There are several checklists available from different sources:
- Critical Appraisal Skills Programme (CASP) Tools & Checklists
- Best Bets Critical Appraisal Worksheets
- Centre for Evidence Based Medicine Critical Appraisal Sheets
- Birmingham Critical Appraisal Skills Programme
- SIGN Critical Appraisal Notes and Checklists
- Understanding Health Research is a tool that 'will guide you through a series of questions to help you to review and interpret a published health research paper'. https://www.understandinghealthresearch.org/
More detailed information about how to read different papers can be found at:
- The Users' Guides to the Medical Literature form a series of articles published in JAMA on which many of the checklists are based. See below for examples. (You will need an NHS Athens user name and password to access some of these articles).
Other useful information about types of study and their relative value can be found at:
- Centre for Evidence Based Medicine - Guide to Study Designs and Levels of Evidence
Glossary
Some technical terminology is used for the statistical aspects of research and you may find it useful to consult a glossary for definitions of these. See Cochrane's Critical Appraisal Glossary for definitions and links to explanations.
Some technical terminology is used for the statistical aspects of research and you may find it useful to consult a glossary for definitions of these. See Cochrane's Critical Appraisal Glossary for definitions and links to explanations.
Further reading
Books
There are several books about critical appraisal available in the library. These are examples of the kind of titles you might find:
AJETUNMOBI, O. 2002. Making sense of critical appraisal. London: Arnold.
BOWERS, D. HOUSE, A. OWENS, D. 2014. Understanding clinical papers. 3rd ed. Chichester: Wiley.
CUTCLIFFE, J. and WARD, M. 2007. Critiquing nursing research. 2nd ed. London: Quay Books.
GREENHALGH, T. 2010. How to read a paper: the basics of evidence-based medicine. 4th ed. Chichester: Wiley-Blackwell.
Also available as an ebook (You will need an NHS Athens user name and password to access the text), with summarised content on 'How to read a paper' also on the BMJ website.
GUYATT, G. RENNIE, D. et al. 2008. Users’ guides to the medical literature. 2nd ed. New York: McGraw-Hill
For other books on critical appraisal, search the online library catalogue
There are also many ebooks on critical appraisal, explore our ebooks collection.
Books
There are several books about critical appraisal available in the library. These are examples of the kind of titles you might find:
AJETUNMOBI, O. 2002. Making sense of critical appraisal. London: Arnold.
BOWERS, D. HOUSE, A. OWENS, D. 2014. Understanding clinical papers. 3rd ed. Chichester: Wiley.
CUTCLIFFE, J. and WARD, M. 2007. Critiquing nursing research. 2nd ed. London: Quay Books.
GREENHALGH, T. 2010. How to read a paper: the basics of evidence-based medicine. 4th ed. Chichester: Wiley-Blackwell.
Also available as an ebook (You will need an NHS Athens user name and password to access the text), with summarised content on 'How to read a paper' also on the BMJ website.
GUYATT, G. RENNIE, D. et al. 2008. Users’ guides to the medical literature. 2nd ed. New York: McGraw-Hill
For other books on critical appraisal, search the online library catalogue
There are also many ebooks on critical appraisal, explore our ebooks collection.
Journal Club Support Service
We offer advice and practical assistance on how to setup and run a journal club, providing you with support and resources to help you do this. Please visit our Journal Club Support Service page for more information.