MERIT 2021.

Study name	D‐mannose to prevent recurrent urinary tract infections (MERIT)
Methods	Study design Parallel, double‐blind RCT Study duration and follow‐up 6 months Study dates January 2019 to March 2021 (updated 04/08/2020, previously: September 2021)
Participants	General information Country: UK Setting: multicentre Inclusion criteria: women ≥ 18 years with recurrent UTIs; presented to ambulatory care with symptoms consistent with UTI ≥ 3 times in the last year or ≥ 2 times in the last 6 months Exclusion criteria: pregnant, lactating or planning pregnancy during the course of the study; formal diagnosis of interstitial cystitis or overactive bladder syndrome; prophylactic antibiotics started in the last 3 months and unwilling to discontinue, or intention to start during the next 6 months; currently using D‐mannose and unwilling to discontinue for the duration of the study; nursing home resident (residential home residents will not be excluded); catheterised, including intermittent self‐catheterization; use of Uromune (an ‘immunostimulant’); participated in a research study involving an investigational product in the past 12 weeks; previous participation in this study Target sample size: 598
Interventions	Treatment group Will take 2 g (due to differences in density this can vary between 1.5 and 2.5 g) D‐mannose daily for 6 months Control group Placebo: will take 2 g (due to differences in density this can vary between 1.5 and 2.5 g) of fructose daily for 6 months Co‐interventions or additional treatments Not reported Follow‐up details 6 months
Outcomes	Primary outcomes The proportion of women experiencing at least one further episode of clinically suspected UTI for which they contact ambulatory care (out‐of‐hours primary care, in‐hours primary care, ambulance or A&E). Assessed by medical notes review within 6 months of study entry Secondary outcomes Number of days of moderately bad (or worse) symptoms of UTI, assessed using a participant diary throughout the study Time to next consultation with a clinically suspected UTI, assessed during a notes review 6 months after study entry Number of clinically suspected UTIs, assessed during a notes review 6 months after study entry Number of microbiologically proven UTIs, assessed during a notes review 6 months after study entry Number of antibiotic courses for UTI; DDD and total mg by antibiotic type, assessed during a notes review 6 months after study entry Report of consumption of antibiotics using diary during periods of infection, recorded in the participant diary throughout the study Proportion of women with a resistant uropathogen cultured during an episode of acute infection, assessed during a notes review 6 months after study entry Hospital admissions related to UTI, assessed during a notes review 6 months after study entry QoL recorded in the participant diary at baseline, 6 months and during UTI episodes on days 1, 3 and 5 Healthcare utilisation recorded in the participant diary and during a notes review 6 months after study entry Acceptability and process evaluation conducted via telephone interviews with up to 25 women throughout the study Tertiary outcomes Antibiotic usage and urine culture results in the five years prior to study entry, assessed during a notes review 6 months after study entry Urine culture results for samples sent during the study period, recorded in the lab results Dependent on further funding: patterns of microbial presence as demonstrated by Next Generation DNA Sequencing in recurrent UTI, exploring the association between frequency of infection and microbial presence and evaluating the impact of D‐mannose on microbial presence, assessed throughout the study
Starting date	12/11/2018: ongoing 22/01/2019: no longer recruiting 04/08/2020: last edited
Contact information	Jared Robinson Primary Care Clinical Trials Unit Nuffield Department of Primary Care Health Sciences University of Oxford Radcliffe Primary Care Building Radcliffe Observatory Quarter Woodstock Road Oxford OX2 6GG United Kingdom +44 (0)1865 617849 merit@phc.ox.ac.uk Trial website: https://www.phctrials.ox.ac.uk/studies/merit
Notes	Funding: National Institute for Health Research (NIHR) (UK) Protocol serial number: 40192