Article History
First Online: 31 July 2020
Declarations
:
: No funding was received for the conduct of this study or the preparation of this article.
: Han Eol Jeong, In-Sun Oh, Woo Jung Kim, and Ju-Young Shin have no conflicts of interest that are directly relevant to the content of this study.
: Our study complies with the Declaration of Helsinki and the study protocol was approved by the Institutional Review Board of Sungkyunkwan University (SKKU 2018-03-010) and obtaining informed consent was waived by the Institutional Review Board.
: Not applicable.
: Not applicable.
: The health insurance claims database of the National Health Insurance Service can be accessed at ExternalRef removed.
: SAS syntax codes are available upon request.
: All authors contributed to the study design and interpretation of the data. HEJ wrote the manuscript. ISO conducted the statistical analyses. WJK interpreted the data and critically revised the manuscript. All authors reviewed and commented on drafts and approved the final manuscript and the decision to submit it for publication. JYS is the guarantor.