Module Components

• Learning Activities

Topics

• Critical Appraisal Principles
• Systematic Review Appraisal
• Randomized Control Trial Appraisal
• Cohort Study Appraisal
• Case Control Study Appraisal
• Module 8 Self-Review

NRSG 790-Methods for Research and Evidence-Based Practice

Module 8: Critically Appraising Quantitative Evidence

Critical Appraisal Principles

The critical appraisal process hinges on three questions that apply to any study:

1. Are the results of the study valid? (Validity)
2. What are the results? (Reliability)
3. Will the results help me in caring for my patients? (Applicability)

This process provides clinicians with the tools to interpret the quality of studies and determine the applicability of the synthesis of multiple studies' results to their patients.

• The validity of a study refers to whether the results of the study were obtained via sound scientific methods. Bias (defined as the systematic deviation from the truth) and/or confounding variables may compromise the validity of the finding.
• The reliability of the study finds were determined by the size of the intervention's effect (the effect size) and how precisely that effect was estimated. This part of critical appraisal examined the numerical data reported in the results section of a study. 
• When critically appraising the the usefulness of a study for clinical decision making, a basic aspect of applicability is to evaluate the study patients in comparison with the patients to whom the evidence would be applied.
• Review this example of a published critical appraisal of a clinical study on CT screening for Lung Cancer
• Review these concepts associated with validity presented in from previous Modules