Objective: To evaluate the efficacy of tolterodine extended release (ER) versus placebo at 1 and 12 weeks using questionnaires and diary measures.
Research design and methods: Subjects with overactive bladder (OAB) were randomized to receive tolterodine ER (4 mg) or placebo for 12 weeks. This double-blind study is registered with ClinicalTrials.gov (identifier: NCT00143377).
Main outcome measures: Subjects completed the Patient Perception of Bladder Condition (PPBC) and 3-day bladder diaries at baseline and weeks 1 and 12, and the Overactive Bladder Questionnaire (OAB-q) at baseline and week 12. PPBC score changes were analyzed using 2-category (improvement, no improvement), 3-category (improvement, no change, deterioration), and 4-category (>or=2-point improvement, 1-point improvement, no change, deterioration) stratifications. Categorical change in PPBC scores from baseline to week 12 was the primary endpoint.
Results: A total of 617 subjects were randomized (tolterodine ER, n = 410; placebo, n = 207). At week 1, a significantly higher percentage of subjects receiving tolterodine ER reported improvement on the PPBC compared with placebo (p < 0.05). Subjects receiving tolterodine ER also had a significantly greater reduction in all OAB symptoms versus placebo (all p < 0.05). At week 12, a higher percentage of tolterodine ER subjects reported PPBC improvement versus placebo subjects. This was significant in the 3- and 4-category analyses (both p < 0.05) but not in the 2-category analysis (the prespecified method of analysis; p = 0.098). Compared with the placebo group, the tolterodine ER group reported significantly greater week 12 improvements in all bladder diary variables (all p < 0.01) as well as in OAB-q Symptom Bother, total Health-Related Quality of Life, Coping, and Concern scores (all p <or= 0.02).
Conclusions: Compared with placebo, subjects receiving tolterodine ER reported significantly greater improvements in nondiary patient-reported outcomes and OAB symptoms at week 12. Improvements in subjects' perception of their bladder-related problems and in OAB symptoms were observed as early as week 1. Further research is required to assess which aspects of subjects' bladder-related problems were improved. A large placebo effect may have prevented the prespecified 2-category analysis of PPBC improvement from reaching statistical significance at week 12, which was the primary endpoint.