Article History
Received: 30 October 2019
Accepted: 30 January 2020
First Online: 7 February 2020
Compliance with ethical standards
: This study was designed, conducted and reported in accordance with the principles of Good Clinical Practice guidance and with the 1964 Helsinki declaration and its later amendments. Prospective ethical approval was granted by a local Institutional Review Board (IRB) and the Venezuelan Health Ministry (IRB reference number #0940), and written consent was obtained from all participants.
: The authors declare that they have no conflict of interest.