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Evidence Based Practice

APPRAISE the evidence

Melnyk & Fineout-Overholt (2015, p. 10), Step 3 = "Critically appraise the evidence".


When appraising or evaluating the evidence (information sources) it is important to pause and be critical because it is not only about a source being reliable or authoritative. The primary goal of appraising or evaluating is to determine the appropriateness and value of a source in context with your purpose.

This can be challenging! And just because you have found your evidence in a library database, this does not mean there isn't a need for you to scrutinize it carefully. So we have provided a number of ways to make this task easier. The CRAAP Test is a quick and easy way to weed out the unsuitable evidence; the other critical appraisal tools provided help you match the evidence more closely to your clinical question.

Please remember that this stage of the EBP framework also includes using the Checklist as indicated by your Faculty!

The quick CRAAP test

DID YOU KNOW that when you first start the research process, there is no need to read everything you find? When applying a quick CRAAP test, you usually look at only the author, title, abstract, and reference list or bibliography. This means you can discard many of the articles without wasting too much time by reading what you don't need from beginning to end!

If you are using the PRISMA flow diagram, use the CRAAP test to SCREEN your RECORDS.






Critical Appraisal Tools

When it comes to finding the best evidence for your clinical question, the CRAAP test is only the first step. Sometimes articles published in peer-reviewed journals have issues with methodology, reporting, or conclusions drawn. Sometimes, the articles even contain research that is actually deliberate academic fraud.

A quick Google search of Alirio Melendez, for e.g., will show that this ex-NUS professor is reported to have made up his research in 21 published articles. Yes, 21 flawed articles! He denies the allegations, but Googling him provides some surprising insight.

The CRAAP test may not pick up on this type of fraud as you can apply the CRAAP test without even reading the article. A more in-depth critical appraisal, therefore, is a crucial part of the EBP process.


fraud alert

Which Checklist to use?

There are many tools available to help you critically appraise the literature you find, but there doesn't seem to be a “gold standard” - they are all just tools to help you decide on the validity of research that has been carried out by others.  

Our suggestion would be to start with a general checklist or tool and then move on to the tools used for specific types of research. The general tool will also help you identify the type of research being conducted. 


If you are having problems identifying the type of research or study used, the following articles may help...

 Ingham-Broomfield, R. (2016). A nurse's guide to mixed methods research. 
Australian Journal of Advanced Nursing, 33(4), 46-52. 
 Ingham-Broomfield, R. (2015). A nurse's guide to qualitative research. 
Australian Journal of Advanced Nursing, 32(3), 34-40.
Ingham-Broomfield, R. (2014). A nurse's guide to quantitative research. 
Australian Journal of Advanced Nursing, 32(2), 32-38.



Read these articles if you need help with your choice of the more targeted critical appraisal tools...

 Buccheri, R. K., & Sharifi, C. (2017). Critical appraisal tools and reporting guidelines for evidence‐based practice. Worldviews on Evidence‐Based Nursing, 14(6), 463-472.


 Majid, U., & Vanstone, M. (2018). Appraising qualitative research for evidence syntheses: A compendium of quality appraisal tools. Qualitative Health Research, 28(13), 2115–2131. 1049732318785358


Please remember, when in doubt, ask your supervisor or teacher.


A List of Appraisal Tools

General Tools and Checklists

If you need help evaluating an article, and do not want to use an in-depth critical appraisal tool, read this article to see an example of a useful general tool... 

 Ingham-Broomfield, R. (2014). A nurse's guide to the critical reading of research. Australian Journal of Advanced Nursing, 32(1), 37-44.


You could also try the general checklist below.

  1. Is the work peer reviewed?
  2. Are there any conflicts of interest, e.g. between the authors and the institution providing the funding?
  3. Are the research questions and objectives clearly defined?
  4. Is the work a systematic review or meta analysis? (useful for citation mining but not normally used in your assignments).
  5. Is the study design appropriate for the research question?
  6. Is the sample size justified and representative of the wider population?
  7. Do the researchers describe how they collected their data?
  8. Does the work clearly describe the measurements used?
  9. Did the researchers use appropriate statistical measures?
  10. Are the research questions and objectives answered?
  11. Did the researchers account for confounding factors that may have influenced both the dependent and independent variables?
  12. Have the researchers drawn conclusions that can be applied beyond the groups represented in the research?
  13. Have the authors declared any conflicts of interest?

Questions 1 to 13 Mostly YES Questions 1 to 13 Mostly NO Questions 1 to 13 half & half
The research can probably be used as evidence. It may be a good idea to find another article. You need to decide based on your own experience.

PRISMA stands for Preferred Reporting Items for Systematic Reviews and Meta-Analyses, and was developed to help researchers report their search strategies in academic writing.


*** With the increasing usage of artificial intelligence (AI) in academia, we need to think about how to acknowledge the use of AI in the PRISMA flow diagram. This example was found in a preprint...

 Gabashvili, I. S. (2023). Artificial intelligence in biomedicine: Systematic review. MedRxiv.


Apart from the Extensions for Scoping Reviews, for example, there are basically 4 PRISMA 2020 flowcharts or flow diagrams...

  • new systematic reviews for searching databases and registers
  • new systematic reviews for searching databases, registers and other sources
  • updated systematic reviews for searching databases and registers
  • updated systematic reviews for searching databases, registers and other sources


A combination of all 4 flow diagrams can be found here

  • A Report is a journal article, preprint, conference abstract, study register entry, clinical study report, dissertation, unpublished manuscript, government report, or any other document providing relevant information
  • A Register is a resource like and where researchers list or register their studies so others can easily find out what they are doing.



See the articles below for published examples of the PRISMA 2020 flow diagram


 Mulyadi, M., Tonapa, S.I., Luneto, S., Lin, W.-T., & Lee, B.-O. (2021). Prevalence of mental health problems and sleep disturbances in nursing students during the COVID-19 pandemic: A systematic review and meta-analysis. Nurse Education in Practice, 57, 103228.


 Kukreti, S., Rifai, A., Padmalatha, S., Lin, C.-Y.., Yu, T., Ko, W.-C., Chen, P.-L., Strong, C., & Ko, N.-Y. (2022). Willingness to obtain COVID-19 vaccination in general population: A systematic review and meta-analysis. Journal of lGobal Health, 12, 05006.