1 Department of Biomedical Sciences, University of Sassari, Italy.
2 Department of Surgical, Oncological and Oral Science, Section of Anaesthesia, Analgesia, Intensive Care and Emergency, Policlinico Paolo Giaccone, University of Palermo, Italy.
3 Centre for Journalology, Clinical Epidemiology Program, Ottawa Hospital Research Institute, Canada dmoher@ohri.ca.
4 School of Epidemiology and Public Health, University of Ottawa, Canada.