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.
Mandy J. Wells, MSc, MClinRes, Honorary Consultant Nurse Researcher, Plymouth Hospitals NHS Trust, Plymouth, Devon, England.
Katharine Jamieson, Diploma, formerly Research Nurse, Faculty of Health Sciences, University of Southampton, Southampton, United Kingdom.
Tamsyn C. W. Markham, PhD, formerly Research Assistant, Faculty of Health Sciences, University of Southampton, Southampton, United Kingdom.
Sue M. Green, PhD, Senior Lecturer, Faculty of Health Sciences, University of Southampton, Southampton, United Kingdom.
Mandy J. Fader, PhD, Professor, Faculty of Health Sciences, University of Southampton, Southampton, United Kingdom.
Correspondence: Mandy Fader, PhD, Faculty of Health Sciences, Level A (MP11) South Academic Block, Southampton General Hospital, Tremona Rd, Southampton SO16 6YD, United Kingdom (firstname.lastname@example.org).
Conflicts of interest: None declared.