Home » Harm


Instructor: Daniel Parker, MD
Email: daniel.parker@duke.edu

Read: Chapter 14: Harm

Learning Goals:

  • List the types of study designs that provide evidence about harm and understand their relative strengths and weaknesses.
  • Apply the criteria for harm studies to an article concerning a pertinent geriatric problem.
  • Calculate an odds ratio, a relative risk, and number needed to harm (NNH) and understand when each is used.
  • Calculate the NNH for death or new mechanical ventilation for hydroxychloquine in the NEJM study


You are a hospitalist managing an 85 y/o Latino patient newly diagnosed with COVID-19 with a new O2 requirement. He’s read that he has a high risk of dying. He tells you he saw the President on TV and the President said that he took hydroxychloroquine which is a good treatment for COVID-19. He wonders why he is not receiving the same treatment. How do you answer this patient?