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Am Fam Physician. 2019;99(6):online

Clinical Question

Does increased water intake decrease urinary tract infection (UTI) recurrence in women?

Bottom Line

Drinking an additional 1.5 liters per day of water halved the recurrence of UTI in women with a history of at least three episodes per year. (Level of Evidence = 1b–)


The researchers enrolled 140 premenopausal women with three or more documented episodes of lower UTI, but not pyelonephritis, in the previous year. In this nonblinded study, the women were randomized, using concealed allocation, to continue their normal levels of water intake or to drink an additional 1.5 liters (three bottles) of Evian-branded water daily for 12 months, which participants on average were able to maintain. Women in the extra water group had approximately one-half as many infections as the usual intake group, with an average of 1.7 documented UTIs over the year compared with an average of 3.2 infections in the usual intake group (P < .001). The extra water resulted in an average of two additional trips to the bathroom each day compared with the usual intake group.

Study design: Randomized controlled trial (nonblinded)

Funding source: Industry

Allocation: Concealed

Setting: Outpatient (any)

Reference: Hooton TM, Vecchio M, Iroz A, et al. Effect of increased daily water intake in premenopausal women with recurrent urinary tract infections: a randomized clinical trial. JAMA Intern Med. 2018;178(11):1509–1515.

Editor's Note: Dr. Shaughnessy is an assistant medical editor for AFP.

POEMs (patient-oriented evidence that matters) are provided by Essential Evidence Plus, a point-of-care clinical decision support system published by Wiley-Blackwell. For more information, see Copyright Wiley-Blackwell. Used with permission.

For definitions of levels of evidence used in POEMs, see

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