Contributorship:
Dr. Yu-Jen Wei: acquisition of data and drafting of the manuscript; Ying-Tzu Ju: acquisition and analysis of data; Dr. Yung-Chieh Lin: research conception and design; Dr. Chung-Dann Kan: analysis and interpretation of data; Dr. Min-Ling Hsieh: acquisition and analysis of data; Dr. Jieh-Neng Wang: conception and design, analysis and interpretation of data, and final approval of the published version.
Ethics: The study protocol was approved by the Institutional Review Board (protocol code A-ER-109-137) in National Cheng Kung University Hospital.
Funding: This research was supported by intramural grant NCKUH-11105003 from National Cheng Kung University Hospital. The funds aided in the fees required for the data analysis, English editing, and publication process.
Competing interests: None of the authors have any competing interests.