Categorical data were analyzed using Fisher's exact test and continuous data using a student t-test.
Differences between categorical variables were assessed with the Chi-square test and continuous variables with the Mann-Whitney test.
Rates were compared by Fisher exact test and continuous variable were compared by t-test.
Dichotomous variables were compared by the chi-squared test and continuous variables by the Student's t-test.
Categorical variables were compared using the χ2 test or Fisher exact test and continuous variables were compared using t-student test, whenever appropriate.
Pre- (1995 2000) and post- (2001 2006) PCV-7 variables were compared using the Chi-squared test and continuous variables were compared using the two-sample t-test.
For paired samples, qualitative variables were analysed using exact Mac Nemar's test and continuous variables (SF-12 components) were analysed using Wilcoxon's rank test.
Categorical variables were compared using chi-squared or Fisher's exact test and continuous variables were compared using the independent samples t-test.
For exploratory testing, categorical variables were compared using χ2 or Fisher's exact test, and continuous variables using the Student t-test for independent samples.
Categorical variables were analysed using Pearson's χ test and continuous variables with Student's t-tests.
We compared categorical data with the chi-squared test and continuous data with the t-test.
