Article History
First Online: 4 April 2018
Compliance with Ethical Standards
: This study was based on healthcare data from the National Health Insurance Research Database provided by the National Health Insurance Administration, Ministry of Health and Welfare, and previously managed by the National Health Research Institutes. The data founders and providers had no role in the study design, data analysis, data interpretation, or writing of the report.
: Fang-Ju Lin, Hung-Wei Lin, and Yunn-Fang Ho declare no conflicts of interest.
: No funding was received for the study.