Funding for this research was provided by:
Text and Data Mining valid from 2020-02-14
Received: 21 October 2019
Accepted: 1 February 2020
First Online: 14 February 2020
Compliance with ethical standards
: The authors declare that they have no conflict of interest.
: The authors RB and BSB are employed as Clinical research scientists and received salary from Indian Council of Medical Research, India, while the author SS is a postdoctoral research fellow at the National Institute of Health, USA, and none of the authors received any financial support/sponsorship to execute this systematic review.