M Vassilaki1, M Linardakis2, Alpha Philalithis2. 1. Department of Social Medicine, Faculty of Medicine, University of Crete, Heraklion, Greece; Department of Neurology and Division of Epidemiology, Mayo Clinic, Rochester, MN, USA. Electronic address: mvassilaki@med.uoc.gr. 2. Department of Social Medicine, Faculty of Medicine, University of Crete, Heraklion, Greece.