About the Authors

Michael L Callaham

To whom correspondence should be addressed. E-mail: mlc@medicine.ucsf.edu

Affiliation Division of Emergency Medicine, University of California, San Francisco, United States of America

John Tercier

Affiliation Department of Sociology, University of Lancaster, Lancaster, United Kingdom

Competing Interests

The authors have declared that no competing interests exist.

Author Contributions

MLC and JT designed the study and contributed to writing the paper. MLC analyzed the data and enrolled participants. JT performed follow-up interviews clarifying data.