Disclosure forms provided by the authors are available with the full text of this article at NEJM.org.

Dr. Brady reports receiving salary support for serving as medical director for Allianz Global Assistance. No other potential conflict of interest relevant to this article was reported.

We thank Linda J. Kesselring, M.S., E.L.S., Department of Emergency Medicine, University of Maryland School of Medicine, for her editorial assistance with an earlier version of the manuscript.