About Critical Appraisal
What is Critical Appraisal?
Critical Appraisal is the process of carefully and systematically examining research to judge its trustworthiness, and its value and relevance in a particular context. (Burls, 2009)
Critical appraisal includes addressing risk of bias, and that involves a careful reading of methods and results. (Tikkenen, Guaytt, 2021).
Why to Appraise?
Why to Appraise?
- Variability in the quality of primary research evidence.
- Poor methodological quality can unreasonably bias results and conclusions, making them unreliable.
- Studies have shown that bias can obscure up to 60% of the real effect of a healthcare intervention.
- Critical appraisal directly impacts patient outcomes and patient safety. (Read More)
- Why We Need Better EvidenceTwenty reasons underpinning the manifesto for better evidence for better healthcare.
CMCC E-Books
Clinical Epidemiology by Publication Date: 2014
Foundations of Evidence-Based Medicine by Publication Date: 2019
Basic & Clinical Biostatistics: Fifth Edition by Publication Date: 2019-10-04
Evidence-Based Medicine by Publication Date: 2018-04-23
Understanding Research Methods for Evidence-Based Practice in Health, 2nd Edition by Publication Date: 2019-06-06
Evidence-Based Practice Across the Health Professions by Publication Date: 2013-08-21- Clinical Epidemiology by Publication Date: 2012-12-25
- Foundations of Evidence-Based Medicine by Publication Date: 2019-11-13
Clinical Epidemiology and Evidence-Based Medicine by Publication Date: 2001-09-07
Basic and Clinical Biostatistics: Fourth Edition by Publication Date: 2004-04-15
Other Tutorials
- CEBM Appraisal VideosA series of videos on teaching Evidence-Based Practice from the Center for Evidence-Based Medicine..
- Critical Appraisal : Critical appraisal videosThese videos cover various aspects of critical appraisal, and are a great way to familiarize yourself with critical appraisal tools and techniques if you are short on time.
GRADE Approach: From Evidence to Recommendations.
GRADE approach: from evidence to recommendations.
GRADE (Grading of Recommendations, Assessment, Development, and Evaluations) is a transparent framework for developing and presenting summaries of evidence and provides a systematic approach for making clinical practice recommendations.
- What is GRADE? How does it work?GRADE (Grading of Recommendations, Assessment, Development, and Evaluations) is a transparent framework for developing and presenting summaries of evidence and provides a systematic approach for making clinical practice recommendations.
- GRADE guidelines: 14. Going from evidence to recommendations: the significance and presentation of recommendationsThe article addresses GRADE’s approach to categorizing, labeling and wording health care recommendations.
- Assessing the Strength of Recommendations: The GRADE ApproachChapter 28.1 Guyatt G, Rennie D, Meade MO, Cook DJ. Users' Guides to The Medical Literature: A Manual for Evidence-Based Clinical Practice. 3rd ed. New York: McGraw-Hill Education; 2015.
This is the step where you evaluate the quality of the research evidence you’ve found. Important skills needed for critical appraisal of a research study:
Structure of a Research Paper
1. Understanding the structure of a research paper (standard layout and organization). Learn how to read and interpret different kinds of research papers:
- Anatomy of a Scientific ArticleA guide to the makeup of a scientific article.
- How to read a paperFind links to articles in the BMJ that explain how to read and interpret different kinds of research papers.
Bias
2. Understanding risk of bias: All clinical studies are vulnerable to bias. Learn about many sources of potential bias that can affect the validity of studies.
- Catalogue of BiasBias enters health studies at all stages and often influences the magnitude and direction of results. To obtain the least biased information, researchers must acknowledge the potential presence of biases and take steps to avoid and minimise their effects.
- Cochrane Bias Methods GroupConsidering bias and conflicts of interest among the included studies.
- Potential publication bias in chiropractic and spinal manipulation research listed on clinicaltrials.govClinical trial registries are used to help improve transparency in trial reporting. Our study aimed to identify potential publication bias in chiropractic and spinal manipulation research by assessing data drawn from published studies listed in clinincaltrials.gov.
Biostats
3. Understanding critical appraisal terminology and biostatistics.
Terminology Resources:
- CMCC’s Glossary of Critical Appraisal TermsDownload the CMCC’s Glossary of Critical Appraisal Terms.
Biostatistical Resources:
- Understanding statistics: BMJ Learning modulesBMJ Learning has two interactive online modules on understanding statistics using practical examples to work through to help with your learning.
- Understanding statistics: RiskRisk in statistical terms refers simply to the probability that an event will occur.
- Evidence-Based Practice: Calculate ResultsDuke university's guide to calculating results.
Critical Appraisal Tools
4. Selecting an appropriate critical appraisal checklist to perform critical appraisal of a research study.
Download CMCC Critical Appraisal Roadmap to select a critical appraisal tool for a specific type of clinical research or study design.
- AXISAn instrument for accessing cross-sectional studies
- CEBM Critical Appraisal ToolsCritical appraisal worksheets to help you appraise the reliability, importance and applicability of clinical evidence.
- CASP Critical Appraisal ChecklistsChecklists from CASP: Critical Appraisal Skills Programme.
- JBI Critical Appraisal ToolsJBI’s critical appraisal tools assist in assessing the trustworthiness, relevance and results of published papers.
- National Institutes of Health (NIH) Study Quality Assessment ToolsIn 2013, NHLBI developed a set of tailored quality assessment tools to assist reviewers in focusing on concepts that are key to a study’s internal validity.
- The Newcastle-Ottawa Scale (NOS)An instrument for assessing the quality of non-randomised studies in meta-analyses, including case-control and cohort studies,
- RoB 2.0For randomized trials.
- ROBINS-IThe Cochrane risk-of-bias tool for assessing risk of bias in the results of non-randomized studies that compare health effects of two or more interventions.
- Scottish Intercollegiate Guidelines Network (SIGN)These checklists were subjected to evaluation and adaptation to meet SIGN’s requirements for a balance between methodological rigour and practicality of use.
- QUADASA Quality Assessment Tool for Diagnostic Accuracy Studies.
Interpretation of Results
5. Interpreting the Results of a Research Study
Evidence-based care requires clinicians to have a sufficient understanding of research study results: “To engage in shared decision-making clinicians must understand the magnitude of benefits, harms and burdens associated with alternative management options—along with the quality of the evidence—and be able to discuss these with patients. To do so, they need a deep understanding of certain EBM basics: what is a relative effect, an absolute effect and how they are related. They need to recognise when (absolute) effects are trivial, small, moderate or large, and understand that absolute effects are far more important to patients than relative effects.” Read more in Tikkenen, Guaytt, 2021.
What is the significance of P-Values and Hypothesis Testing? What is the difference between Standard Deviation and Standard Error? What is a Confidence Interval and how do I interpret it? What are Degrees of Freedom and why are they important? How to interpret Measures of Agreement, Diagnostic Accuracy Measures,(Sensitivity, Specificity, PPV, NPV, LR+, LR-), Odds Ratios and Relative Risk?
Watch CMCC videos recorded by Dr. Kim Ross to learn how to read the results of research studies:
CMCC Library Videos
Watch these CMCC Library videos to learn how to Appraise the evidence for its quality, reliability and relevance.
CMCC Print Books
Evidence-Based Practice Across the Health Professions by Call Number: WB 102.5 H711e 2017
Practical Biostatistics by Call Number: QH 323.5 S83 2021
Clinical Evidence Made Easy by Call Number: WA 950 H315c 2014
Essential Evidence-Based Medicine by Call Number: WB 102.5 M468e 2010
Evaluating Research in Health and Social Care by Call Number: W 20.5 E915 2000
How to Appraise Research: A Guide for Chiropractic Students and Practitioners by Call Number: W 18.2 H145 2003
Evidence-Based Statistics by Call Number: WA 950 C132e 2021
Epidemiology and Biostatistics by Call Number: WA 950 K42e 2009
Research Methods by Call Number: W 20.5 H965r 2011
Research Methods in Health by Call Number: W 20.5 R432 2014
Key Topics in Evidence-Based Medicine by Call Number: WB 102 M145 2001
Fundamentals of Evidence Based Medicine by Call Number: WB 102.5 P911 2013
Critical Evaluation of Research in Physical Rehabilitation by Call Number: WB 460 H474 2000
Clinical Epidemiology by Call Number: WA 950 C645 2015
