Stratakis, N
Gielen, M
Chatzi, L
Zeegers, M P
Article History
Received: 3 April 2014
Revised: 31 May 2014
Accepted: 6 July 2014
First Online: 13 August 2014
Change Date: 2 September 2014
Change Type: Update
Change Details: Supplementary file PRISMA Checklist added
Competing interests
: The authors declare no conflict of interest.