[1] Univ London Imperial Coll Sci & Technol, Dept Epidemiol & Publ Hlth, London, England
[2] Akademisch Ziekenhuis St Rafael, Louvain, Belgium
[3] Johns Hopkins Univ, Welch Ctr, Baltimore, MD USA
[4] Northwestern Univ, Dept Prevent Med, Chicago, IL 60611 USA
[5] Shiga Univ Med Sci, Dept Hlth Sci, Otsu, Shiga 52021, Japan
[6] Fu Wai Hosp, Dept Epidemiol, Beijing, Peoples R China