Submitted for Publication: February 23, 2011; final revision received September 9, 2011; accepted September 22, 2011.
Author Contributions: Drs Chen and Wu contributed equally to this study. Drs Chen, Wu, and Chang had full access to all the data in the study and take responsibility for the integrity of the data and the accuracy of the data analysis. Study concept and design: Y.-J. Chen, Wu, and Chang. Acquisition of data: Y.-J. Chen, Wu, Shen, T.-T. Chen, and Chang. Analysis and interpretation of data: Y.-J. Chen, Wu, and Chang. Drafting of the manuscript: Y.-J. Chen. Critical revision of the manuscript for important intellectual content: Y.-J. Chen, Wu, Shen, T.-T. Chen, and Chang. Statistical analysis: Y.-J. Chen and T.-T. Chen. Obtained funding: Y.-J. Chen, Wu, and Shen. Administrative, technical, and material support: Y.-J. Chen, Wu, and Shen. Study supervision: Wu and Chang.
Financial Disclosure: None reported.
Funding/Support: This study was partly supported by grants TCVGH-996801B and TCVGH-996802C from Taichung Veterans General Hospital.
Disclaimer: This study is based in part on data from the NHIRD provided by the Bureau of National Health Insurance, Department of Health, and managed by the National Health Research Institute. The interpretations and conclusions contained herein do not represent those of the Bureau of National Health Insurance, Department of Health, or the National Health Research Institute.