[1] Univ Valencia, Dept Prevent Med, Unit Publ Hlth & Environm Care, E-46003 Valencia, Spain
[2] Dr Pest Univ Hosp, Clin Epidemiol Unit, Valencia, Spain
[3] Univ Aarhus, Danish Epidemiol Sci Ctr, Aarhus, Denmark
[4] Univ Calif Los Angeles, Sch Publ Hlth, Dept Epidemiol, Los Angeles, CA 90024 USA
[5] Univ So Denmark, Inst Publ Hlth Epidemiol, Odense, Denmark