Brown M, Williamson PR, Sutton L, et al. - Single-centre, parallel, two-arm, open-label pilot randomized controlled trial was designed to provide information that would inform the design and conduct of a definitive trial comparing onabotulinum toxin A with extended-release tolterodine for the management of therapy-resistant idiopathic overactive bladder in children. Researchers explored rates of eligibility, recruitment, acceptability of randomization, loss to follow-up, acceptability of urodynamic assessment, and obtain primary outcome data for sample size estimation. A total of 98 patients were included in the study. Recruitment to a definitive trial was found to be useful whether a large number of centres are involved, though future consideration is needed regarding trial design.