- Correspondence to: J Arnold Medical Care Research Unit, University of Sheffield, Regent Court, 30 Regent Street, Sheffield S1 4DA, UK;
- Accepted March 26, 2007
- First published June 20, 2007.
If you wish to reuse any or all of this article please use the link below which will take you to the Copyright Clearance Center’s RightsLink service. You will be able to get a quick price and instant permission to reuse the content in many different ways.