The effects and costs of cranberry use to prevent symptomatic urinary tract intections in nursing home residents.

Objectives/research questions.

To assess the effects and costs of cranberry use to prevent symptomatic UTIs in nursing home residents.



Study design.

Double-blinded randomised placebo-controlled multi-centre intervention trial.


Study population and sample size.

All nursing home residents ≥ 65 years, except coumarin users, stratified by risk of symptomatic UTI (high versus low). The group with high risk of UTI includes nursing home residents with long-term catheterisation (> 1 month) and/or diabetes mellitus and/or a history of at least one treated symptomatic UTI in the preceding year.

To detect a 50% reduction in cumulative incidence of symptomatic UTIs, 1000 residents will be enrolled within a period of three months.



Eligibility Criteria.

All nursing home residents ≥ 65 years and a life expectancy > 1 month are eligible, except those using coumarin.


Study procedures.

Intervention: Cranberry capsule/sachet or placebo (both administered twice daily) during one year. The Cranberry capusule/sachet contains 1.8% proanthocyanidins (PACS)


The study does not interfere with standard care. Diagnostics and treatment will occur in accordance with current clinical guidelines.


Outcome measures.

• Effects: time to first symptomatic UTI, number of symptomatic UTIs per included resident, quality of life, care dependency, compliance, side effects, medical consumption, resistance patterns of etiologic microbial agents, and costs.

• The economic evaluation will include a cost-effectiveness analysis (costs per prevented UTI) and a cost-utility analysis (costs per QALY).



Analysis.

All data-analysis will be done on the basis of intention-to-treat analysis. Descriptive statistics, multivariate Cox-analyses and multivariate linear mixed models will be used.



Time schedule.

M 1-7 preparation, M 8-10 inclusion of residents, M 8-22 intervention period, M 23-36 analyses and publication.

N/A

At start study, after 6 and 12 months.

During UTI 3 times a week for 3 weeks.

- Intervention (n=500): 2x dd Cranberry during 1 year.

- Controles (n=500): 2x dd Placebo during 1 year.