Learn More About the Levels (or Hierarchy) of Evidence
To learn more about levels of evidence and research designs, read How to Read a Paper by Trisha Greenhalgh and watch the video tutorials below.
How to Read a Paper by Call Number: ebookISBN: 9781119484721Publication Date: 2019-04-04This book addresses the common criticisms of evidence-based healthcare, dispelling many of its myths and misconceptions, while providing a pragmatic framework for testing the validity of healthcare literature. It also helps readers to understand the central principles of evidence-based medicine, critically evaluate published data, and implement the results in practical settings.
This video by the Duke University Medical Center Library provides a great overview of all the studies in the EBP levels of Evidence Pyramid.
Learn About Experimental Research Methods
Dr. Terry Shaneyfelt demonstrates how to use data from a study to calculate an individual patients risk of the study outcome. This is important to know how to do because the patients you see in the office or in the hospital are often sicker or healthier than those enrolled in studies.
Dr. Terry Shaneyfelt describes why blinding is important and the most commonly used methods to blind in an RCT.
This episode is part of Healthcare Triage’s series on Improving Reproducibility in Research.
Dr. Terry Shaneyfelt describes the imporrtance of concealed allocation in a randomized controlled trial. Concealed allocation is different from blinding.
Dr. Terry Shaneyfelt explains the utility of the Intention to treat analysis.
What are the differences between Per Protocol, As Treated, and Intention to Treat?
Key Concepts in Prognostic Studies
Dr. Terry Shaneyfelt provides an overview of study designs used to glean prognostic information.
Learn About Study Designs
- How to Read a Systematic Review and Meta-analysis and Apply the Results to Patient CareThis article is part of the JAMA Users’ Guides to the Medical Literature series. "When searching for evidence to answer a clinical question, it is preferable to seek a systematic review, especially one that includes a meta-analysis.Clinical decisions should be based on the totality of the best evidence and not the results of individual studies."
Dr Jack Bowden provides a brief overview of a meta-analysis. What is it, and how it helps scientists to assess and combine evidence from many different studies.
There are several types of review articles that you may encounter. Dr. Terry Shaneyfelt describes the diffrence between a traditional, narrative review versus a Systematic Review.
- Designing a research project: randomised controlled trials and their principles"The randomised control trial (RCT) is a trial in which subjects are randomly assigned to one of two groups: one (the experimental group) receiving the intervention that is being tested, and the other (the comparison group or control) receiving an alternative (conventional) treatment (fig 1). The two groups are then followed up to see if there are any differences between them in outcome. The results and subsequent analysis of the trial are used to assess the effectiveness of the intervention, which is the extent to which a treatment, procedure, or service does patients more good than harm. RCTs are the most stringent way of determining whether a cause-effect relation exists between the intervention and the outcome."
- Therapy (Randomized Trials)Chapter 6: Therapy discusses issues of bias, treatment effects, and applying the results to patient care. Guyatt G. JAMA’s Users’ Guides to the Medical Literature: Essentials of Evidence-Based Clinical Practice. New York: McGraw-Hill Medical; 2014.
- Randomised Controlled Trials: The Randomisation ProcessRandomised controlled trials are often considered the optimal study design, especially in clinical research. This introductory video provides a brief overview of key concepts in randomization.
- RCT Handout"RCTs are experimental studies in which researchers perform an experiment and purposely assign one group in the study to the new “treatment” (the intervention group) and the other group to a comparison “treatment” (control or comparison group). "
Dr. Terry Shaneyfelt provides an overview of cohort study design and their strengths and limitations.
Case-control studies are observational studies that have the greatest risk of bias. Dr. Terry Shaneyfelt describes the basic design of case-control studies and discuss their strengths and weaknesses.
Faculty from the Harvard School of Public Health describes a case report. The video is intended to start at 1:40. Other studies are described in this lecture following the section on case reports.
Writing Case Reports by ISBN: 9783319418995Publication Date: 2017This book provides medical students and physicians with a practical, step-by-step guide on how to write and publish a medical case report.
Learn About Observational Research Methods
- Observational research methods. Research design II: cohort, cross sectional, and case-control studiesThis article from the BMJ describes "Cohort, cross sectional, and case-control studies...collectively referred to as observational studies. Often these studies are the only practicable method of studying various problems, for example, studies of aetiology, instances where a randomised controlled trial might be unethical, or if the condition to be studied is rare. Cohort studies are used to study incidence, causes, and prognosis. Because they measure events in chronological order they can be used to distinguish between cause and effect."