Acknowledgements
We would like to thank Peter Hokland for continued support, Bodil Lind Andersen for excellent technical assistance, and Marcus Celik Hansen for help with graphic assistance.
Potential conflict of interest
Disclosure forms provided by the authors are available with the full text of this article at www.informahealthcare.com/lal.
Supplementary material available online
Supplementary Figure 1 and Table I showing further data.