Objectives

We aimed to compare the efficacy of 2 commonly used contemporary vaginal estrogen administrations versus placebo for the prevention of urinary tract infection (UTI) in postmenopausal women with a clinical diagnosis of recurrent UTI (rUTI).

Methods

This was an investigator-initiated, multicenter, single-blind, randomized, placebo-controlled trial of vaginal estrogen (delivered via ring or cream) compared with placebo. Postmenopausal women with documented rUTI were randomized to receive either vaginal estrogen (via ring or cream) or placebo cream in a 1:1:1 fashion. The primary outcome was occurrence of UTI at 6 months. After 6 months, open-label use of ring or active cream was offered to all participants for an additional 6 months. Because of slower than expected recruitment, sample size calculations and block randomization schema were revised to combine estrogen groups (ring or cream) for statistical comparisons to placebo cream in a 1:1 fashion.

Results

Thirty-five women were randomized with 9 dropouts (1 ring, 2 cream, and 6 placebo) prior to the 6 months. Intention-to-treat analysis (assuming dropouts as failures) revealed fewer women treated with vaginal estrogen had a UTI within 6 months versus placebo (11/18 vs 16/17, respectively; P = 0.041). Per-protocol analysis revealed fewer subjects treated with vaginal estrogen had a UTI at 6 months (8/15 vs 10/11, respectively; P = 0.036).

Conclusions

Commonly prescribed forms of vaginal estrogen with contemporary dosing schedules prevent UTIs in postmenopausal women with an active diagnosis of rUTI.

Standardized conditions for collection, preservation and storage of urine for microbiome research have not been established. We aimed to identify the effects of the use of preservative AssayAssure® (AA), and the effects of storage time and temperatures on reproducibility of urine microbiome results. We sequenced the V3-4 segment of the 16S rRNA gene to characterize the bacterial community in the urine of a cohort of women. Each woman provided a single voided urine sample, which was divided into aliquots and stored with and without AA, at three different temperatures (room temperature [RT], 4 °C, or -20 °C), and for various time periods up to 4 days. There were significant microbiome differences in urine specimens stored with and without AA at all temperatures, but the most significant differences were observed in alpha diversity (estimated number of taxa) at RT. Specimens preserved at 4 °C and -20 °C for up to 4 days with or without AA had no significant alpha diversity differences. However, significant alpha diversity differences were observed in samples stored without AA at RT. Generally, there was greater microbiome preservation with AA than without AA at all time points and temperatures, although not all results were statistically significant. Addition of AA preservative, shorter storage times, and colder temperatures are most favorable for urinary microbiome reproducibility.