[1] Univ Helsinki, Inst Behav Sci, POB 9, FIN-00014 Helsinki, Finland
[2] Univ Edinburgh, Univ BHF Ctr Cardiovasc Sci, Queens Med Res Inst, Edinburgh, Midlothian, Scotland
[3] Folkhalsan Res Ctr, Helsinki, Finland
[4] Univ Helsinki, Helsinki Collegium Adv Studies, Helsinki, Finland
[5] Univ Helsinki, Childrens Hosp, Helsinki, Finland
[6] Helsinki Univ Hosp, Helsinki, Finland
[7] Natl Inst Hlth & Welf, Chron Dis Prevent Unit, Helsinki, Finland
[8] Univ Helsinki, Dept Gen Practice & Primary Hlth Care, Helsinki, Finland
[9] Oulu Univ, Cent Hosp, Dept Obstet & Gynaecol, Med Res Ctr Oulu, Oulu, Finland
[10] Univ Oulu, Oulu, Finland