Number Needed to Treat Calculator
Calculates the number needed to treat from an absolute risk reduction. The worked condition keeps the inputs and convention visible for checking.
Set the labeled inputs
Number Needed to Treat
A note on convention at the chosen parameters for number needed to treat
Calculates the number needed to treat from an absolute risk reduction. The named quantity is number needed to treat calculator. This is section 1 of the number needed to treat discussion.
Save the inputs, formula convention, units, exclusions, and unrounded output with this result. This statement is conditional on the number needed to treat setup and section 1.
For number needed to treat, preserve the source definition, the stated units, and the named convention beside the displayed number. A second analyst should be able to reconstruct the same result without guessing which population or setup was intended.
A second look at the condition before comparing methods for number needed to treat
Always state the outcome, follow-up period, and rounding convention; NNT is not timeless. The named quantity is number needed to treat calculator. This is section 2 of the number needed to treat discussion.
Reducing risk from .20 to .10 gives NNT 10. This statement is conditional on the number needed to treat setup and section 2.
For number needed to treat, preserve the denominator choice, the stated units, and the named convention beside the displayed number. A second analyst should be able to reconstruct the same result without guessing which population or setup was intended.
Reading the planned inputs when the result is reused for number needed to treat
Always state the outcome, follow-up period, and rounding convention; NNT is not timeless. The named quantity is number needed to treat calculator. This is section 3 of the number needed to treat discussion.
Save the inputs, formula convention, units, exclusions, and unrounded output with this result. This statement is conditional on the number needed to treat setup and section 3.
For number needed to treat, preserve the comparison group, the stated units, and the named convention beside the displayed number. A second analyst should be able to reconstruct the same result without guessing which population or setup was intended.
A related calculation is number needed to harm.
Where the method applies in the worked condition for number needed to treat
Calculates the number needed to treat from an absolute risk reduction. The named quantity is number needed to treat calculator. This is section 4 of the number needed to treat discussion.
Reducing risk from .20 to .10 gives NNT 10. This statement is conditional on the number needed to treat setup and section 4.
For number needed to treat, preserve the time boundary, the stated units, and the named convention beside the displayed number. A second analyst should be able to reconstruct the same result without guessing which population or setup was intended.
When another method fits before reporting for number needed to treat
Always state the outcome, follow-up period, and rounding convention; NNT is not timeless. The named quantity is number needed to treat calculator. This is section 5 of the number needed to treat discussion.
Save the inputs, formula convention, units, exclusions, and unrounded output with this result. This statement is conditional on the number needed to treat setup and section 5.
For number needed to treat, preserve the design boundary, the stated units, and the named convention beside the displayed number. A second analyst should be able to reconstruct the same result without guessing which population or setup was intended.
A controlled alternative under the stated model for number needed to treat
Always state the outcome, follow-up period, and rounding convention; NNT is not timeless. The named quantity is number needed to treat calculator. This is section 6 of the number needed to treat discussion.
Reducing risk from .20 to .10 gives NNT 10. This statement is conditional on the number needed to treat setup and section 6.
For number needed to treat, preserve the rounding rule, the stated units, and the named convention beside the displayed number. A second analyst should be able to reconstruct the same result without guessing which population or setup was intended.
What the result can support when the sample changes for number needed to treat
Calculates the number needed to treat from an absolute risk reduction. The named quantity is number needed to treat calculator. This is section 7 of the number needed to treat discussion.
Save the inputs, formula convention, units, exclusions, and unrounded output with this result. This statement is conditional on the number needed to treat setup and section 7.
For number needed to treat, preserve the reference population, the stated units, and the named convention beside the displayed number. A second analyst should be able to reconstruct the same result without guessing which population or setup was intended.
Questions about this calculation
For the worked condition, when should the calculation be repeated for number needed to treat?
Keep the inputs, units, method, exclusions, and unrounded output together. The reported quantity here is number needed to treat calculator.
When software results differ, can a boundary value be entered for number needed to treat?
Keep the inputs, units, method, exclusions, and unrounded output together. The reported quantity here is number needed to treat calculator.
Before reporting, how many digits should be reported for number needed to treat?
Keep the inputs, units, method, exclusions, and unrounded output together. The reported quantity here is number needed to treat calculator.
When inputs change, does this result establish a causal relationship for number needed to treat?
Keep the inputs, units, method, exclusions, and unrounded output together. The reported quantity here is number needed to treat calculator.