Efficacy

Efficacy is the ability to perform a task to a satisfactory or expected degree. The word comes from the same roots as effectiveness, and it has often been used synonymously, although in pharmacology a distinction is now often made between efficacy and effectiveness.[1]

The word efficacy is used in pharmacology and medicine to refer both to the maximum response achievable from a pharmaceutical drug in research settings,[2] and to the capacity for sufficient therapeutic effect or beneficial change in clinical settings.

  1. ^ Zimmer, Carl (20 November 2020). "2 Companies Say Their Vaccines Are 95% Effective. What Does That Mean? You might assume that 95 out of every 100 people vaccinated will be protected from Covid-19. But that's not how the math works". The New York Times. Retrieved 21 November 2020.
  2. ^ Cite error: The named reference HolfordSheiner was invoked but never defined (see the help page).