Dykstra et al. (A-41) studied 15 female patients with urinary frequency with or without incontinence. The women were treated with botulinum toxin type B (BTX-B). A t test of the pre/post-difference in frequency indicated that these 15 patients experienced an average of 5.27 fewer frequency episodes per day after treatment with BTX-B. The p value for the test was less than 0.001.