Increased Water Intake for Recurrent Cysitis

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Hooton TM, et al. "Effect of Increased Daily Water Intake in Premenopausal Women With Recurrent Urinary Tract Infections". JAMA Internal Medicine. 2018. 178(11):1509-1515.

Clinical Question

In premenopausal women who experience 3 urinary tract infections per year, does increasing water intake to more than 1.5L per day decrease the number of recurrent urinary tract infections?

Bottom Line

In women who drink less than 1.5L of water per day, increasing that amount decreased the number of urinary tract infections over a 12 month period.

Major Points

Acute uncomplicated cystitis can affect half of the female population over their lifetime. While self-limiting, the vast majority will report pain, discomfort, and a decrease in quality of life. Commonly antimicrobials are prescribed to treat this infection and in the modern era of growing antimicrobial resistance, finding interventions to limit their utilization and saving this precious resource for the future or my more serious infections. Prior to this trial, the common teaching for women with recurrent UTI was to increase their water intake.

This trial 2018 trial, sponsored by makers of bottle water, included 140 healthy, premenopausal women with low fluid intake, compared adding an additional 1.5L of bottled water to their usual fluid intake (n=70) to a control group (n=70). For their primary outcome, they observed 1.7 episodes of cystitis in the water group compared to 3.2 in the control (difference 1.5, 95% CI 1.2-1.8, P < 0.001). The amount of antimicrobials utilized was significantly lower, 1.9 vs. 3.6 (difference 1.7, 95% CI 1.3-2.1, P < 0.001). There was also a non-surprising increase in the number of voids and volume of urine produced.

This trial, conducted at a single site, had a number of limitations including be sponsored by makers of bottled water. It was also open-label, but blinding would have been exceptionally challenging given the intervention. Finally, the outcome was self-reported but they did attempt to confirm with culture as much as possible. The effect seen in this trial may be associated with the increase in voiding and output, decreasing the bacterial burden within the bladder. Overall, this trial showed that a simple intervention of increasing water intake in a population with low water intake may decrease the utilization of antimicrobials, and may be made more accessible by utilizing tap water instead of bottled.


IDSA/ESCMID International clinical practice guidelines for the treatment of acute uncomplicated cystitis and pyelonephritis in women: A 2010 update, adapted [1]:

Not addressed.


  • randomized, open-label, control study
  • N=140
    • additional 1.5L water (n=70)
    • control (n=70)
  • Setting: Sofia, Bulgaria
  • Enrollment: 13 December 2013 to 13 July 2016
  • Follow-up: 12 months (93% completed follow-up)
  • Analysis: intention-to-treat
  • Primary Outcome: Number of cystitis episodes over 12 months


Inclusion Criteria

  • ≥18 years old
  • good general health
  • no current UTI symptoms
  • ≥3 symptomatic episodes of cystitis in the past year resulting in a documented visit to a clinician
  • ≥1 episode culture confirmed (≥10^3 colony-forming units [CFU]/mL bacteria in a voided midstream urine culture)
  • self-reported water consumption <1.5 L of fluid daily

Exclusion Criteria

  • current symptoms of UTI
  • history of pyelonephritis in the past 12 months
  • interstitial cystitis
  • symptomatic vulvovaginitis
  • were pregnant, lactating, or planning to become pregnant in the following 12 months

Baseline Characteristics

All participants displayed

  • Demographics: mean age 35.3 years
  • Physiologic parameters: 92% sexually active in past month, mean 3.3 UTI in past year, 72% with 3 UTI in past year, 28% ≥4 UTI in past year, 0.9L 24-h urine output
  • Anthropomorphics: mean BMI 23.3
  • Fluid intake 1.1L per day ( 0.5L water, 0.2L hot drinks, 0.1L Ethanol, 0.3L “other”)
  • Causative organism: 78% Escherichia coli, 10% Klebsiella species, 4% Proteus


  • additional 1.5L of bottled water to usual fluid intake
  • control (no additional water to usual fluid intake)


Comparisons are water group vs. Control group.

Primary Outcomes

Mean cystitis episodes over 12 months
1.7 vs. 3.2 (difference 1.5, 95% CI 1.2-1.8) P < 0.001

Secondary Outcomes

Mean number of antimicrobial courses prescribed
1.9 vs. 3.6 (difference 1.7, 95% CI 1.3-2.1) P < 0.001
Mean time interval between cystitis episodes
142.8 days vs. 84.4 days (difference 58.4, 95% CI 39.4-77.4) P < 0.001
Mean time to first cystitis episode
148 days vs. 93.5 days (hazard ratio 0.51, 95% CI 0.36-0.74) P < 0.001)
Mean increase in 24-hour urine volume
1.3L vs. 0.1L, P < 0.001
Number of cystitis episodes
111 vs. 216
93% of water group had ≤2
88% of control had ≥3

Adverse Events

Not separate between groups No serious ADR reported, 9% reported headache, 6% reported GI symptoms


  • Open label design (attempted mitigation via monthly phone follow-up, measured urine volume/osmolality, cultured confirmed UTI)
  • Single site, limiting generalizability
  • Self-reported primary outcome
  • Study sponsor sells intervention


  • Danone Research, seller of the bottled water used in the study

Further Reading

  1. Gupta K et al. International clinical practice guidelines for the treatment of acute uncomplicated cystitis and pyelonephritis in women: A 2010 update by the Infectious Diseases Society of America and the European Society for Microbiology and Infectious Diseases. Clin. Infect. Dis. 2011. 52:e103-20.