Applying Evidence

  1. Number needed to treat (NNT)
    • number of patients need to be treated for one to benefit
    • Inverse of the absolute risk reduction
    • The difference between the rate of events in the treatment (Pa) and control (Pc)
    • NNT=1(Pa-Pc)
  2. Number needed to harm
    • Number of patients harmed rather than benefited.
    • •Aspirin use
    • Prevent heart attack or stroke - Risk of bleeding
    • May be close
    • •Fluoride use
    • Caries prevention >> Risk of rare bone cancer
    • •dental radiograph - same type of situation
  3. Statistical power / Sample size determination:
    • 1) Expected difference in the mean values between the groups.
    • 2) Expected scatter.
    • 3) Significance level (generally p< 0.05)
Author
neopho
ID
323917
Card Set
Applying Evidence
Description
Applying evidence mid term
Updated