For the primary outcome (day frequency) measure it was calculated that 90 participants equally divided into placebo and control were required to detect a difference of 1.6 urinary frequency episodes per day (2.7SD) between treatment and placebo groups, with a two-tailed alpha of 0.05 and a power of 80%. For total incontinence, 53 participants were required equally divided into each group to detect a difference of 1.2 episodes per day (2.2SD), while for urgency 54 was required in each group to detect a difference of 2 per day (3.7SD). To account for potential drop-outs and variations in presenting symptoms, a total of 150 participants were recruited.