Effect of baseline symptom severity on continence improvement mediated by oxybutynin chloride topical gel.

Background: In a recent placebo-controlled Phase III study, oxybutynin chloride topical gel (OTG) significantly improved urinary continence in patients with overactive bladder. In this post hoc analysis, the effect of incontinence severity on OTG-mediated improvement in continence was evaluated.

Methods: Change from baseline in the number of incontinence episodes was evaluated in patients with two to three incontinence episodes/day (moderate incontinence) and those with more than three incontinence episodes/day (severe incontinence).

Results: In patients with moderate (n = 171) and severe (n = 556) incontinence, reduction in incontinence episodes (mean ± standard deviation) was greater (P < 0.01) with OTG (moderate, -1.7 ± 1.4; severe, -3.6 ± 3.0) than with placebo (moderate, -1.2 ± 1.3; severe, -3.1 ± 3.4). Continence achievement rate with OTG was 48.2% (placebo, 24.4%) among patients with moderate incontinence and 17.8% (placebo, 12.1%) among those with severe incontinence.

Conclusion: Absolute placebo-adjusted reduction in incontinence episodes with OTG was not affected by baseline incontinence severity. Continence achievement was more likely if symptoms were less severe.