[1] Chi Mei Med Ctr, Dept Internal Med, Div Hematol Oncol, Liouying, Taiwan
[2] Southern Taiwan Univ Sci & Technol, Dept Senior Welf & Serv, Tainan, Taiwan
[3] Natl Cheng Kung Univ, Dept Environm & Occupat Hlth, Tainan, Taiwan
[4] Chi Mei Med Ctr, Dept Occupat Med, Tainan, Taiwan
[5] Tainan Municipal Hosp, Dept Occupat Med, Tainan, Taiwan
[6] Natl Cheng Kung Univ, Coll Med, Dept Publ Hlth, Tainan, Taiwan