- Statistical analysis. The primary endpoint and secondary endpoints will be analyzed by qualitative test of Mantel-Haentzel. The homogeneity of odds ratios (existence of a significant level of anxiety) will be tested by the Breslow-Day.Comparing the duration of each examination, the dose of lidocaine instilled, satisfaction scores and the number of increments and decrements in both groups will be made by Mann-Whitney test. For these variables, the possible interactions between the type of action and treatment are analyzed in a ANOVA model.