[1] Chinese Univ Hong Kong, Ctr Clin Trials, Shatin, Hong Kong, Peoples R China
[2] Beking Univ, Epidemiol, Beijing, Peoples R China
[3] Peking Univ, Epidemiol, Beijing, Peoples R China
[4] Chinese Univ Hong Kong, Med & Therapeut, Shatin, Hong Kong, Peoples R China
[5] Chinese Univ Hong Kong, Community & Family Med, Shatin, Hong Kong, Peoples R China