Response to David Nace and Paul Drinka.

Abstract

To the Editor: We appreciate the thoughtful comments of Drs. Nace and Drinka concerning our article.1, 2 They highlighted our definitions of clinical and strict urinary tract infection (UTI) and concluded that, by using the clinical definition, it is not possible to infer any benefit from cranberry capsules in the prevention of UTI. We agree that, for many studies, the appropriate criterion standard for diagnosing UTI is detection of the pathogen in the presence of clinical symptoms. A less-rigorous definition can easily lead to overdiagnosis and false conclusions, but residents in long-term care facilities (LTCF) are a vulnerable population, mostly with severe cognitive impairment, multiple chronic comorbidities, functional disabilities, and urinary incontinence. Signs and symptoms of UTI are frequently absent,3 and differentiating asymptomatic from symptomatic UTI in older persons with dementia is difficult and challenging.4, 5 The use of the criterion standard for diagnosing UTI is not suitable for LTCF residents and would lead to substantial underdiagnosis. As a result, there is no criterion standard in diagnosing UTI in LTCF populations, and most clinical criteria to ascertain UTI in LTCF residents are based on consensus.6-8 To make research in real-world LTCF populations possible, we have chosen a clinical UTI definition. Our clinical definition is a broad and practical definition, following clinical practice guidelines for LTCF residents9, 10 and based on the experience of the elderly care physician and nursing staff, which is consistent with a previous study.5 Experienced staff can achieve even better diagnostic precision than urine culture.11 There is also recent evidence that micturition-related signs and symptoms are predictive of UTI.4 Although our clinical definition is different from the strict definition, it closely reflects clinical care in LTCF and adds knowledge to practice guidelines to assist physicians in making decisions. Moreover, our cost-effectiveness analysis showed the relevance of our clinical definition, because clinical UTIs were followed by a significant deterioration in quality of life, survival, care dependency, and costs.12 Our study concludes that, for elderly LTCF residents with high UTI risk, taking cranberry capsules twice daily results in a lower incidence of clinical UTI. In daily practice, prevention with cranberry will also reduce antibiotic prescription, including inappropriate prescriptions. Conflict of Interest: The authors do not have financial or other kind of personal conflicts with this report. Author Contributions: All authors participated in the conception, drafting, and approval of the report. Sponsor's Role: None.