Article History
Received: 20 May 2020
Accepted: 15 June 2020
First Online: 24 June 2020
Compliance with ethical standards
:
: All the authors declare that they have no conflicts of interest.
: This retrospective chart review study involving human participants was in accordance with the ethical standards of the institutional and national research committee and with the 1964 Helsinki Declaration and its later amendments or comparable ethical standards. The Human Investigation Committee (IRB) of Faculty of Medicine, Chiang Mai University, Thailand approved this study.
: For this type of study, inform consent is not required.