The authors enrolled 140 premenopausal women whose self-reported fluid intake was low -- less than 1.5 liters of total fluid a day -- and who had had at least three episodes of AUC in the previous year. They were randomly assigned 1:1 to increase their water intake by 1.5 L a day or to make no change in their habits. Women in the intervention group were given 500 mL bottles of water and urged to begin drinking one at the start of each meal and to finish it before the next meal. Over the study period, the 70 women in the intervention group:
- Increased their water intake significantly compared with the control group -- an increase of 1.15 L on average versus an average drop of 0.01 L
- Raised their average total fluid intake by 1.65 L versus 0.03 L among the control group
- Upped average urine volume and number of urine voids -- 1.40 L versus 0.04 L and 2.2 a day versus a decrease of 0.2, respectively
- Saw a decrease in urine osmolality of 408 mOsm/kg versus 35 in controls
The average number of recurrent AUC episodes in the water group over the year was 1.6, compared with 3.1 among the control women. Those numbers yielded an odds ratio for AUC of 0.52, which was highly significant. The average number of antimicrobial regimens used to treat AUC was 1.8 in the water group and 3.5 in the control group, which was again significant. The average number of days to first AUC after the start of the study and the mean number of days between episodes was longer for those in the water group. Recurrent UTI, sometimes with ESBL organisms, is a common problem. Perhaps preventive water intake of a liter and a half a day is a remedy.