[1] Oulu Univ Hosp, Unit Gen Practice, Oulu, Finland
[2] Univ Oulu, Dept Publ Hlth Sci & Gen Practice, Oulu, Finland
[3] Univ Turku, Dept Publ Hlth & Gen Practice, Turku, Finland
[4] Univ Tampere, Sch Med, Dept Internal Med, FIN-33101 Tampere, Finland
[5] Univ Tampere, Sch Publ Hlth, Biometry Unit, FIN-33101 Tampere, Finland
[6] Tampere Univ Hosp, Tampere, Finland
[7] Univ Kuopio, Dept Publ Hlth & Gen Practice, FIN-70211 Kuopio, Finland