- Correspondence to A A M van Oeffelen, Julius Center for Health Sciences and Primary Care, University Medical Center Utrecht, P.O. Box 85500, Utrecht 3508 GA, The Netherlands;
- Received December 22, 2013
- Revised April 22, 2014
- Accepted May 12, 2014
- First published June 9, 2014.
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.