[1] Erasmus Med Ctr, Dept Publ Hlth, NL-3000 DR Rotterdam, Netherlands
[2] Univ Zurich, Inst Social & Prevent Med, CH-8006 Zurich, Switzerland
[3] Municipal Hlth Serv, Barcelona, Spain
[4] Univ Helsinki, Dept Sociol, Helsinki, Finland
[5] Univ Madrid, Dept Prevent Med & Publ Hlth, Madrid 3, Spain
[6] Univ Turin, Dept Microbiol & Publ Hlth, Turin, Italy
[7] Off Natl Stat, Hlth & Care Div, London, England
[8] Stat Norway, Div Hlth Stat, Oslo, Norway
[9] Free Univ Brussels, Brussels, Belgium
[10] Stat Denmark, Res & Methodol Div, Copenhagen, Denmark