[1] Univ Amsterdam, Acad Med Ctr, Dept Clin Epidemiol & Biostat, NL-1100 DD Amsterdam, Netherlands
[2] Univ Southampton, MRC, Epidemiol Resource Ctr, Southampton, Hants, England
[3] Univ Amsterdam, Acad Med Ctr, Dept Vasc Med, NL-1105 AZ Amsterdam, Netherlands
[4] Univ Amsterdam, Acad Med Ctr, Dept Internal Med, NL-1105 AZ Amsterdam, Netherlands
[5] Univ Amsterdam, Acad Med Ctr, Dept Obstet & Gynaecol, NL-1105 AZ Amsterdam, Netherlands