Previous studies demonstrate that tolterodine extended release (ER) significantly improves urgency urinary incontinence (UUI) episodes. Instruments that measure patient-reported outcomes (PROs) provide additional information that is valuable for assessing whether clinical improvements are meaningful to the patient. This study determined the correlation of changes in bladder diary variables and other PROs in subjects with overactive bladder (OAB).
Subjects with OAB, urinary frequency, and UUI were treated with 4 mg once-daily tolterodine ER or placebo for 12 weeks. Subjects completed 7-day bladder diaries, the Patient Perception of Bladder Condition (PPBC), and the King's Health Questionnaire (KHQ) at baseline and week 12. Only subjects who reported at least some minor bladder-related problems at baseline (PPBC score ≥ 3) were included in this analysis.
Reductions in UUI episodes per week were significantly greater in the tolterodine ER group (n = 500) compared with the placebo group (n = 487) at week 12 (-71% vs -33%, P < 0.0001). A significantly greater percentage of subjects in the tolterodine ER group reported improvement on the PPBC versus placebo (58% vs 45%, P < 0.0001), and 7 of 10 KHQ domains were significantly improved versus placebo (all P < 0.05). Significant correlations were found for median percentage changes in UUI episodes with changes in PPBC scores (r = 0.35,P < 0.0001) and the 7 improved KHQ domains (r = 0.16–0.32, P ≤ 0.0011). Changes in PPBC scores and all KHQ domains were significantly correlated (r = 0.13–0.38, P ≤ 0.009) in the tolterodine ER group. Correlations among endpoints in the placebo group were similar to those observed in the tolterodine ER group.
Improvement in UUI episodes after 12 weeks of treatment with tolterodine ER or placebo was correlated with improvements in patients' perception of their bladder-related problems and health-related quality of life. Correlations were moderate in magnitude but statistically significant, suggesting that PROs are important and relevant measures for evaluating OAB treatment.