Intraservice time is not a proxy for operating room time.

@article{Hannenberg2004IntraserviceTI,
  title={Intraservice time is not a proxy for operating room time.},
  author={Alexander A. Hannenberg and Norman A. Cohen},
  journal={Anesthesiology},
  year={2004},
  volume={101 4},
  pages={
          1041; author reply 1041-2
        }
}

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