Amendments from Version 1
[version 2; peer review: 2 approved]No competing interests were disclosed.




There are some changes made in the revised version. The title has been changed by adding “: a randomized control trial”. We have added more information in the methods such as make it is clear who are the healthcare workers. We have corrected some typos in the numbering related to the statistics. We have corrected the labels of the figures and now the connection between the figures and the explanations in the text have been corrected and checked for the correctness. Table 7 was removed.