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Evidence Based Medicine: Module 3: Appraise

Critically Appraising the Evidence

In the critical appraisal process, you are seeking to determine what accounts for a study's results. Specifically, you are looking to determine whether a study's results are most likely due to bias, chance, confounding, or truth.1

The questions needed to critically appraise a specific study will depend on the study design but broadly speaking, when appraising a study, you are looking to determine:

  1. Validity: Are the study results valid?  Was an appropriate research method used and did the researchers attempt to minimize bias and confounding?
  2. Significance: What are the results and are they statistically significant? What is the clinical importance of the findings?
  3. Generalizability: Are the results of the study generalizable beyond the study setting? Can the results be applied to your patients and/or in your practice setting?

The ability to critically appraisal a study requires an understanding of epidemiological and biostatistical concepts, particularly clinical study design, biases and confounders in clinical research, basic biostatistics, and common measures of association in biomedical studies.

1. Fletcher GS, Fletcher RH. Clinical epidemiology : the essentials . 6th ed. Philadelphia: Lippincott Williams & Wilkins/Wolters Kluwer; 2021. Chapter 12, Cause; p.204-218

Pre-Appraised Resources