Background: Acute cystitis is a common condition in women and associated with morbidity. A commonly recommended preventative measure is increased oral hydration, but there is limited evidence to support this claim.
Study design: Open-label, randomized, controlled study.
Setting: Clinical research center based in Sofia, Bulgaria.
Synopsis: A 12-month trial done at a clinical research center including healthy women with recurrent cystitis who drank less than 1.5 L of fluid daily. One group was instructed to drink 1.5 L of water/day in addition to their normal fluid intake, and the other was advised not to drink any additional fluid. The mean number of cystitis episodes in the intervention group was 1.7 (95% confidence interval, 1.5-1.8), compared with 3.2 (95% CI, 3.0-3.4) in the control group, which was a statistically significant difference of 1.5 (95% CI, 1.2-1.8; P less than .01).
Though antibiotic prophylaxis is more effective at reducing cystitis, increased daily water intake is a safe and inexpensive method to prevent cystitis without increasing exposure to antimicrobial therapy. This study did rely on information obtained from phone calls with patients. It is also an open-label study design in which patients were not blinded to their assigned group. This would be less of an issue if episodes of cystitis were confirmed with culture. Another limitation of this study is that it included only ambulatory patients and excluded patients with pyelonephritis, so it may be less applicable to our hospitalized patients.
Bottom line: This study shows a benefit in recurrent cystitis by increased water intake in premenopausal women.
Citation: Hooton TM et al. Effect of increased daily water intake in premenopausal women with recurrent urinary tract infections. JAMA Intern Med. 2018 Nov;178(11):1509-15.
Dr. Astik is medical director, clinical documentation, at Northwestern University Feinberg School of Medicine and a hospitalist at Northwestern Memorial Hospital, both in Chicago.