Purpose: The primary aims of this study were to test the methodology for use in a future randomized control trial and to investigate the effect of drinking caffeinated versus decaffeinated fluids on symptoms of overactive bladder (OAB) in women.
Design: A double-blind, randomized, crossover study was conducted.
Methods: Fourteen community-dwelling women newly diagnosed with OAB and a history of caffeine consumption were randomly allocated to group A (14-day caffeinated drink period followed by 14-day decaffeinated drink period) or group B (14-day decaffeinated drink period followed by 14-day caffeinated drink period). The periods were preceded by a 14-day run-in period and interspersed with a 14-day washout period. Primary outcomes were episodes of urgency, frequency, volume per void, and incontinence obtained each period on 3-day bladder diaries. Secondary outcome measures were OAB symptom severity and health-related quality of life (QOL) recorded each period using International Consultation on Incontinence-Overactive Bladder Module (ICIQ-OAB) and ICIQ-OAB-Quality of Life (ICIQ-OABqol) tools. Effects of caffeine reduction were measured each day using visual analogue scales.
Results: Eleven participants completed the study. A significant reduction in urgency (P < .01) and frequency (P < .05) of urinary voids on day 3 of the diary, total ICIQ-OAB score (P < .01), and a non-significant directional change for the total ICIQ-OABqol score (P = .065) was found using sign tests for the period of decaffeinated compared to caffeinated drink intake. No significant differences were found for any caffeine withdrawal measures.
Conclusions: Despite the small sample size, this pilot study demonstrated that reducing caffeine intake may alleviate the severity of some symptoms and health-related QOL factors associated with OAB. Furthermore, caffeine substitutes were well tolerated.