Statistical analysis
We used SPSS, version 24 (IBM, Armonk, NY, USA) for all statistical analysis except for the repeated measure analyses by Proc Genmod which was done in SAS version 9.2. Normally distributed continuous variables are presented as means with standard deviations (SDs). Other participants characteristics are reported as counts with percentages. Rates of POP and bother were analyzed with chi-squared tests. The study was analyzed by intention-to-treat. Additional per-protocol analysis was done. Significance levels were set to 0.05.