[1] Chonnam Natl Univ, Sch Med, Dept Prevent Med, Kwangju, South Korea
[2] Univ Pittsburgh, Grad Sch Publ Hlth, Dept Epidemiol, Pittsburgh, PA 15261 USA
[3] Univ Calif San Diego, Dept Family & Prevent Med, San Diego, CA 92103 USA
[4] Tobago Hlth Studies Off, Scarborough, Tobago, Trinidad Tobago
[5] Chinese Univ Hong Kong, Jockey Club Ctr Osteoporosis Care & Control, Hong Kong, Hong Kong, Peoples R China
[6] Chungnam Natl Univ, Sch Med, Dept Prevent Med, Taejon, South Korea