1. Clinical Epidemiology Laboratory, Faculty of Nursing, National and Kapodistrian University of Athens, Athens, Greece
2. Faculty of Nursing, National and Kapodistrian University of Athens, Athens, Greece
3. Department of Tourism Studies, University of Piraeus, Piraeus, Greece
4. Center for Health Services Management and Evaluation, Faculty of Nursing, National and Kapodistrian University of Athens, Athens, Greece