Hui-Fen Chiu, Chih-Cheng Chen, Shang-Shyue Tsai, Shu-Chen Ho and Chun-Yuh Yang*
* Corresponding author: Chun-Yuh Yang chunyuh@kmu.edu.tw
BMC Public Health 2012, 12:857 doi:10.1186/1471-2458-12-857