Ahern, Thomas P
Horváth-Puhó, Erzsébet
Spindler, Karen-Lise Garm
Sørensen, Henrik Toft
Ording, Anne G
Erichsen, Rune
Article History
Received: 6 July 2015
Revised: 14 October 2015
Accepted: 2 November 2015
First Online: 1 December 2015
Competing interests
: The authors declare no conflict of interest.