[1] Taipei Med Univ, Wan Fang Hosp, Dept Orthoped Surg, Taipei, Taiwan
[2] Natl Taipei Univ, Dept Stat, Taipei, Taiwan
[3] Chung Hua Univ, Dept Hospitality Management, Hsinchu, Taiwan
[4] China Med Univ, Grad Inst Biostat, Taichung, Taiwan
[5] China Med Univ, Dept Publ Hlth, Taichung, Taiwan
[6] Changhua Christian Hosp, Ctr Biostat & Epidemiol, Changhua, Taiwan
[7] Changhua Christian Hosp, Healthcare Syst Operat Ctr, Changhua, Taiwan