1. University of Milano-Bicocca, Italy (G.M.).
2. Policlinico di Monza, Italy (G.M.).
3. National Centre for Healthcare Research & Pharmacoepidemiology, University of Milano-Bicocca, Italy (G.C.).
4. Laboratory of Healthcare Research & Pharmacoepidemiology, Unit of Biostatistics, Epidemiology and Public Health, Department of Statistics and Quantitative Methods, University of Milano-Bicocca, Italy (G.C.).