Evidence Based Practice: 5 A's

"Critical appraisal is the process of carefully and systematically examining research to judge its trustworthiness, and its value and relevance in particular context. It is an essential skill for evidence-based medicine because it allows clinicians to find and use research evidence reliably and efficiently" 

Burls, A. (2009). What is critical appraisal? In What Is This Series: Evidence-based medicine. Available online at What is Critical Appraisal?

The basics of Critical Appraisal: 

1. Validity: measured by research design, method and procedure
2. Trustworthiness: 
   • Clear statement of findings
   • Precise documentation of results
   • Rigorous data analysis
   • Analysis of how findings fit within established research
3. Value & relevance: Are results applicable to the clinical question and/or population of interest?

Why is Critical Appraisal Important: 

• Before applying evidence to a clinical problem it is vital that the researcher critically evaluate: 
  • Study design utilized to determine the research evidence
  • Possible bias and reliability of evidence presented
  • Determine the practical relevance of the research findings

Source: CASP

Critical appraisal is a systematic process of analyzing research to determine the strength of the validity, reliability and relevance. 

1. What is the focus of the study?
   • The focus will address the population, intervention and outcome 
2. What type of study was completed? 
   • Is the study design matched with the domain of the research question? 
3. What are the study characteristics?
   • Use the PICO question format to determine the study characteristics:
     • What are/is the Patient/Population/Problem? How were the participants selected? 
     • What intervention/treatment/test is being studied?
     • Does the study compare the intervention to a control group? 
     • What outcomes are being assessed? Are the outcomes objective, subjective, surrogate? 
4. How did the researchers address bias within the study?
   • Were the study participants randomly assigned to study groups? 
   • Was the randomization process double or triple blind? 
   • Were the study groups similar at the beginning of the study? 
   • What was the percentage of participant attrition? How many left the study prior to completion? 
   • Apart from the tested intervention, were the groups of the study treated equally? 
5. What are the study results? Are the results valid?
   • Were the effects of the study provided comprehensively? 
   • What outcomes were measured? Were they clearly specified? 
   • Would the drop out rate effect the study results? 
   • Is there any missing or incomplete data? 
   • Are the potential sources of bias identified? 
   • How large was the treatment/intervention effect? 
   • Do the authors provide access to the raw data? 
6. Is this study relevant to your population, intervention and outcome? 
   • Are the results generalizable? 
   • Compare study participants to your population of study. Are the outcome measures relevant? 
   • Is this intervention applicable to your patient/population? (Including patient values)
   • Would this intervention provide greater value to the your patient/population? 
   • Would participant differences alter the outcomes? 
   • Are there limitations in this study that would impact the outcomes desired? 

University of Canberra library. (2021). Module 3: Appraisal. Evidence-based practice in health. https://canberra.libguides.com/c.php?g=599346&p=4149244