Results were expressed as mean ± standard deviation (SD). Categorical variables were analysed with the χ2 test and the Fisher test. We compared mean between groups with the t-test, ANOVA test and Bonferroni test. We used Mann-Whitney U test, non-parametric ANOVA and Kruskal-Wallis to compare median between groups. The SPSS v.14.0 software package was used to perform all statistical analysis (SPSS Inc. IL, USA). A p-value of 0.05 was considered a statistically significant level of difference. The analysis of the main objective was conducted on an intention-to-treat. Secondary objectives were analysed according to protocol.