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Evidence-Based Practice

A guide to the elements and process of EBP

Explaining the Results (videos and articles)

Number Needed to Treat

How to calculate the number-needed-to-treat  Terry Shaneyfelt.  video 3 min

The NNT Tutorial  Grahm Walker video 4 min

Absolute Risk Reduction, Relative Risk Reduction, Relative Risk

How to calculate a relative risk  Terry Shaneyfelt.  video 3 min

Basic Statistics for Clinicians: Assessing the effects of treatment: measures of association   CMAJ. 1995 Feb 1;152(3):351-7. Erratum in: Can Med Assoc J 1995 Mar 15;152(6):813.

Odds Ratios

Gordon Guyatt explaining odds ratios video 21 min

How to calculate an odds ratio  Terry Shaneyfelt.  video 3 min


Intention-to-treat analysis - What it is and why is it important?  Terry Shaneyfelt  video 5min

What is intention-to-treat analysis? Allan Shaughnessy video 1 min

Forest Plots

How to interpret a forest plot.  Terry Shaneyfelt video 5 min 

Interpreting and understanding meta-analysis graphs--a practical guide. Aust Fam Physician. 2006 Aug;35(8):635-8. PubMed PMID: 16894442

Confidence Intervals

Confidence intervals.  Terry Shaneyfelt video 5 min

Basic Statistics for Clinicians: Interpreting study results: confidence intervals  CMAJ. 1995 Jan 15;152(2):169-73.

Sensitivity, Specificity and Likelihood Ratios

Sensitivity & specificity  H. Gilbert Welch video 8 min

How to calculate sensitivity  Terry Shaneyfelt video 4 min

How to calculate specificity  Terry Shaneyfelt video 3 min

What are likelihood ratios and how are they used  Terry Shaneyfelt video 10 min


more videos by Terry Shaneyfelt, M.D.

more videos by Allan Shaughnessy

Stating the meaning of effect size measures in plain English  

Endgames statistical series in BMJ by Philip Sedgwick

Sources for Likelihood Ratios