Post hoc subgroup analysis

After the statistical analysis was finished as laid down in the study protocol, a subgroup of the efficacy analysis set (n = 385 patients) consisting of two treatment groups according to the dosage regime “1 times a day 45 mg of TC” (n = 90 patients) or “3 times a day 15 mg of TC” (n = 295 patients) documented over the whole treatment period, was used to compare treatment outcomes in relation to the two administration schemes (Fig. 1). All analyses were descriptive and explorative in nature.

Assignment of patients to the analytical populations

For between-group comparisons relating the main variables, we used effect size measures for evaluating the strength of the observed result. We calculated Cohen’s r for the median change of average number of voids/24 h between Visit 1 and the last evaluable visit; and Cramér’s V for the combination in the occurrence of incontinence episodes at Visit 1 to the last evaluable visit, as well as for the assessments of efficacy and tolerability by physicians and patients. For facilitating the interpretation of effect sizes, we used the defined reference values by Cohen [46] and Ellis [47].