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Number Needed to Treat (NNT)

(Last edited: Tuesday, 14 March 2017, 8:55 AM)

 

 

  • The number of patients that need to be treated before one person would experience the desired outcome
  • Number needed to treat to benefit: number of patients that need to be treated before one person would experience a beneficial outcome
  • Example: NNT= 20: this means that 20 people need to be given a stroke prevention drug before one stroke can be prevented
  • Number needed to treat to harm: number of patients that need to be treated before one person would experience a harmful outcome
  • Example: NNT= 40: this means that 40 people can be treated with cardiac surgery before one person dies 

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