[1] Natl Sch Publ Hlth, Dept Hlth Serv Org & Management, 196 Alexandras Ave, Athens 11521, Greece
[2] Natl & Kapodistrian Univ Athens, Sch Med, Stavros Niarchos Fdn, Collaborat Ctr Clin Epidemiol & Outcomes Res CLEO, Athens, Greece
[3] Athens Univ, Attikon Hosp, Med Sch, Dept Vasc Surg, Athens, Greece
[4] Univ Ioannina, Sch Med, Dept Surg, Vasc Surg Unit, Ioannina, Greece
[5] Aristotle Univ Thessaloniki, AHEPA Hosp, Dept Cardiol 1, Thessaloniki, Greece
[6] Univ Thessaly, Dept Resp Med, Univ Hosp Larissa, Larisa, Greece
[7] Univ Athens, Evangelismos Hosp, Dept Crit Care & Pulm Serv, Med Sch, Athens, Greece