Original Publication
Open Access

The Making Evidence Based Medicine Simple Series – Harm Module

Published: August 7, 2013 | 10.15766/mep_2374-8265.9480

Included in this publication:

  • Critical Appraisal Form - Azithromycin and Risk of Cardiovascular Death.pdf
  • Critical Appraisal Form - Harm - Blank.doc
  • EBM Teaching Tips - General Approach to the Modules.pdf
  • EMB Teaching Tips - Harm.pdf
  • Instructor's Guide - MESS Curriculum - Harm Module.pdf
  • Instructor's Guide - MESS Curriculum - Overview.pdf
  • Lecture Notes- Harm Studies.pdf
  • Lecture Slides - Harm Studies.pdf
  • Lecture Slides - Harm Studies.ppt
  • QUIZ ANSWERS Harm.pdf
  • QUIZ Harm.pdf
  • Video ScreenCast - Harm Studies.mp4

To view all publication components, extract (i.e., unzip) them from the downloaded .zip file.

Editor's Note: This publication predates our implementation of the Educational Summary Report in 2016 and thus displays a different format than newer publications.


The Making Evidence Based Medicine Simple Series is an evidence based clinical practice curriculum. It consists of six modules that review the articles types addressing the most common clinical questions (i.e., diagnosis, therapy, harm, prognosis, meta-analysis and clinical decision rules). Each module reviews an article from the medical literature using the Users Guide to Medical Literature criteria for validity, results and applicability. Each modules includes a PowerPoint presentation with a script, a video of the presentation with narration, a quiz with answers, tips for teaching the module, a blank review form, and a completed critical article review for the article reviewed in the module.

The Harm Module reviews the appraisal of the validity, results, and applicability of a retrospective cohort study from a state Medicaid database of adults receiving Azithromycin. The study addresses the following clinical question: Do adult patients receiving Azithromycin when compared to no antibiotics or other antibiotics have an increased risk of cardiovascular deaths? In addition, this module reviews the following critical appraisal skills: (1) identifying the strengths and weaknesses of cohort and case control studies, (2) differentiating between prevalence and incidence, (3) differentiating between risk and odds, (4) interpreting a relative risk and an odds ratio, (5) identifying and factors likely to increase causality, and (5) interpreting a number needed to harm.

Educational Objectives

By the end of this session, learners will be able to:

  1. Evaluate the validity, results, and applicability of a harm article.
  2. Develop a “clinical bottom line” for a harm article.
  3. Differentiate between prospective and retrospective cohort studies.
  4. Identify the strengths and weaknesses of cohort studies.
  5. Identify the strengths and weaknesses of case-control studies.
  6. Outline a population/patient, intervention/indicator, comparator/control, and outcome question from a harm study.
  7. Understand the validity criteria for a cohort and case-control study.
  8. Differentiate between prevalence and incidence.
  9. Differentiate between a risk and odds.
  10. Identify measures of association based on prevalence and incidence.
  11. Define and interpret a relative risk and an odds ratio as a measure of association.
  12. Define and interpret a hazard ratio as a measure of association.
  13. Interpret confidence intervals for precision.
  14. Interpret confidence intervals for statistical significance.
  15. Identify factors increasing the likelihood of causality versus association.
  16. Interpret a Kaplan-Meier survival curve.
  17. Understand the applicability criteria for a harm study.
  18. Calculate and interpret an absolute risk reduction/difference/increase.
  19. Calculate and interpret a number needed to harm.

Author Information

  • Michael Mojica, MD: New York University School of Medicine

None to report.

None to report.


Mojica M. The making evidence based medicine simple series – harm module. MedEdPORTAL. 2013;9:9480. https://doi.org/10.15766/mep_2374-8265.9480