Key points are not available for this paper at this time.
This research was partially supported by the organizations in which the study was accomplished; we thank them for their financial and psychological assistance. Bruce Katcher and Hannah Hirsh helped with some of the analyses reported herein. Our colleagues Phil Bobko, Pete Dachler, Irv Goldstein, Nancy Jagmin, Janina Latack, and John Slocum helped us with their valuable comments on an earlier version of this article.
Schneider et al. (Sun,) studied this question.