Applying Evidence

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)
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
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

323917

Card Set

Applying Evidence

Description

Applying evidence mid term

Updated

2016-10-03T14:15:13Z

Show Answers