[1] Oncol Network Res & Prevent Inst ISPRO, Clin Epidemiol Unit, Florence, Italy
[2] Univ Utrecht, Univ Med Ctr Utrecht, Julius Ctr Hlth Sci & Primary Care, Utrecht, Netherlands
[3] Univ Nottingham, Sch Hlth Sci, Nottingham, England
[4] Univ Clin Pulm & Allerg Dis Golnik, Golnik, Slovenia
[5] Univ Sheffield, Hlth Sci Sch, Sheffield, England
[6] Univ Med Ctr, Erasmus MC, Rotterdam, Netherlands