Acknowledgements
Preparation of this chapter was supported by the U.S. Department of Veterans Affairs, Veterans
Health Administration, Health Services Research and Development Service for the first author and
by start-up funding from Stony Brook University for the second author. The views expressed are
those of authors and do not necessarily represent the views of the Department of Veterans Affairs
or Stony Brook University. We thank Keith Humphreys for his comments on an earlier draft of this
chapter.