1. Department of Medical Informatics; Erasmus University Medical Center; Rotterdam the Netherlands
2. Department of Clinical and Experimental Medicine; University of Messina; Messina Italy
3. Health Search; Italian College of General Practitioners; Florence Italy
4. Regional Agency for Healthcare Services of Tuscany; Florence Italy
5. Department of Primary Care and Public Health Sciences; King′s College London; London UK
6. Department of Clinical Epidemiology; Aarhus University Hospital; Aarhus Denmark
7. Department of Medical and Surgical Sciences; University of Bologna; Bologna Italy
8. Leibniz Institute for Epidemiology and Prevention Research - BIPS; Bremen Germany
9. PHARMO Institute for Drug Outcomes Research; Utrecht the Netherlands