[1] Univ Jyvaskyla, Chydenius Inst, FIN-67100 Kokkola, Finland
[2] Natl Res & Dev Ctr Welf & Hlth, Hlth Serv Res Unit, Helsinki, Finland
[3] Univ Michigan, Inst Gerontol, Ann Arbor, MI 48109 USA
[4] Univ Michigan, Sch Publ Hlth, Ann Arbor, MI 48109 USA
[5] Ann Arbor VA Med Ctr, Ann Arbor, MI USA
[6] Univ Helsinki, Dept Publ Hlth, FIN-00014 Helsinki, Finland
[7] Karolinska Inst, Med Management Ctr, Stockholm, Sweden