Risk of Outcome in Treated Group:
Risk of Outcome in Control Group:
Absolute Risk Reduction:
Relative Risk:
Relative Risk Reduction
Number Needed To Treat

Number needed to treat (NNT)
The number of patients who must receive a particular therapy for one to benefit. You might tell a patient that an NNT of 10 means that the chance that he/she will benefit in this way from the treatment is 1 in 10. To calculate NNT use the calculator.

FORMULAS

NNT = 1 / ((C/D)-(A/B)

or

NNT= (ERC)(RRR) where RRR = RRR as entered or 1-RR