Funding for this research was provided by:
University of Birmingham
Article History
Received: 26 February 2019
Revised: 4 May 2019
Accepted: 17 June 2019
First Online: 22 July 2019
Compliance with ethical standards
:
: The authors declare that they have no conflict of interest.
: For this type of retrospective study, formal consent was not required. All procedures performed were in accordance with the ethical standards of the local research committee and with the 1964 Helsinki declaration and its later amendments.