Confidence intervals for the number needed to treat. Pooling numbers needed to treat may not be reliable.

@article{Cates1999ConfidenceIF,
  title={Confidence intervals for the number needed to treat. Pooling numbers needed to treat may not be reliable.},
  author={Christopher Cates},
  journal={BMJ},
  year={1999},
  volume={318 7200},
  pages={1764-5}
}