**2.3 Statistical analysis**

The software Microsoft Excel for Windows® and the Statistical Package for Social Sciences® 12.0 (SPSS) were used to create a database and to conduct statistical analysis. Measures of central tendency and dispersion were used to describe data, with means and standard deviations for quantitative variables. The Student t test for paired samples was used for comparisons between groups. The level of significance was established at p<0.05.
