1 Department of Medicine and Aging Sciences, University of Chieti, Via dei Vestini 5, 66013 Chieti, Italy; Regional Health Care Agency of Abruzzo, Via Attilio Monti 9, Pescara, Italy.
2 Stanford Prevention Research Center, Department of Medicine, Stanford University School of Medicine, Stanford, CA, USA; Department of Health Research and Policy, Stanford University School of Medicine, Stanford, CA, USA; Department of Statistics, Stanford University School of Humanities and Sciences, Stanford, CA, USA; Meta-Research Innovation Center at Stanford (METRICS), Stanford, CA, USA. Electronic address: jioannid@stanford.edu.