Effect of fluid management on fluid intake and urge incontinence in a trial for overactive bladder in women

Study Type - Therapy (RCT) Level of Evidence 1b Objectives To explore whether instruction in fluid management resulted in changes in fluid intake and incontinence over a 10-week study period in women with urinary urge incontinence (UUI), as fluid management might be a critical strategy in treating this condition. Patients and Methods In the 'Behaviour Enhances Drug Reduction of Incontinence' trial, women with predominant UUI were randomized to daily treatment with tolterodine or tolterodine combined with behavioural therapies, among which were individualized instructions on fluid management. Patients in both groups received general fluid management instructions, while in the drug + behaviour arm, those with excessive urine output (>2.1 L/day) had additional individualized instruction during each of four study visits to learn behavioural strategies. Variables measured at baseline and at 10 weeks were type of incontinence, using the Medical, Epidemiological, and Social Aspects of Aging questionnaire, severity of incontinence by number of incontinence episodes based on a 7-day diary, number of voids/24 h (F₂₄), urgency rating, 24-h fluid intake (I₂₄) and 24-h volume voided (V₂₄), volume average (V_avg), pad use, bothersomeness of UUI (Urogenital Distress Inventory and Overactive Bladder questionnaire), and quality of life (Incontinence Impact Questionnaire-7 and Short-Form-12). Results Leakage episodes/24 h, V₂₄, I₂₄ and average urgency ratings all significantly decreased from baseline to 10 weeks (P < 0.001 for each). V_avg increased (P < 0.001), as did voids/L intake (P = 0.01). None of the changes in diary variable outcomes differed by treatment group after accounting for these changes between baseline and 10 weeks. In a multivariable model, treatment group was not associated with change in V₂₄ from baseline to 10 weeks (P = 0.81), but the difference in the number of accidents/diary day, F₂₄, I₂₄, and average voids/day each were positively related with the change in V₂₄ (P < 0.001 for each). Patients had a response to fluid management instructions; the decrease in the percentage of women with a V₂₄ of >2.1 L between baseline and follow-up was statistically significant (P = 0.01 McNemar's test). CONCLUSION General fluid instructions can contribute to the reduction in UUI symptoms for women taking anticholinergic medications, but additional individualized instructions along with other behavioural therapies did little to further improve the outcome.