Data entry is carried out in the Open Clinica and analysis will be performed using the computer program SAS. As regards the choice of the statistical tests applied to data in which there will be no continuous differences, that will be analyzed by paired t-test or a corresponding non-parametric test, as categorical data are analyzed using the Pearson χ2 tests. Other data (e.g., from questionnaires) are analyzed using logistic regression and chi square or Mantel Haenzel test. Significance level is set at 0.05.