1 Centre of Research for Effectiveness and Appropriateness in Medicine (CREAM), DiBiMIS, University of Palermo, Piazza delle Cliniche 2, 90127 Palermo, Italy; Department of Internal Medicine, National Relevance and High Specialization Hospital Trust, ARNAS Civico, Di Cristina, Benfratelli, Palermo, Italy. Electronic address: s.corrao@tiscali.it.
2 Centre of Research for Effectiveness and Appropriateness in Medicine (CREAM), DiBiMIS, University of Palermo, Piazza delle Cliniche 2, 90127 Palermo, Italy.