4. Statistical analysis Data were summarized for continuous variables as mean ±SD (Max, Min) and number (%) for categorical variables. Statistical comparisons were performed by Fisher exact test for categorical variables and non-parametric Wilcoxon rank sum test for continuous variables. Comparison of continuous variables between groups was performed using non-parametric. Survival was estimated with the Kaplan-Meier method. The relationship between categorical parameters and outcome measures was assessed by non-parametric log-rank test. Finally we use an ANOVA test to compare biomarkers between CAA-ri, Alzheimer's Disease (AD) and controls. For all analyses, a two-tailed p-value <0.05 was used as the criterion for statistical significance. Statistical analyses were performed using R version 3.0.1 (The R Foundation for Statistical Computing). To test the association between MCB's number and clinical outcome we categorized the number of microbleeds in 3 categories: 0 to 99 CMB, 100 to 199 and more than 200 per patient.