Toward New Criteria for the Laboratory, Clinical, and Presumptive Diagnosis of UTI
Loading...
Date
2006-08
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
The Ohio State University
Abstract
Urinary tract infections (UTIs) are the most common bacterial infection, accounting for 25% of all infections. UTIs occur in all populations and ages, however, infection is most common in women, especially sexually active women. One half of all women will experience a UTI in their lifetime, and one in three women will receive antimicrobial therapy for a UTI. In addition, the financial impact is enormous with costs exceeding $1.6 billion for community acquired UTI (Foxman, 2003).
In current practice, the gold standard for diagnosis is urine culture, although a standard cutoff value does not exist. The primary purpose of this study is to determine what combination of symptoms and/or diagnostic tests best predict the incidence of UTI in non-pregnant females in terms of sensitivity, specificity, positive predictive value, and negative predictive value. The goal is to develop a gold standard for diagnosis.
Research Questions were: 1) At which colony forming unit (cfu) level on the urine culture are the symptoms, signs, and dipstick results the most sensitive and specific? 2.) Which cfu level on the urine culture yields the highest positive predictive value and negative predictive value for each sign, symptom, and dipstick result? 3.) What sign, symptom, or combination yields the best clinical result?
This secondary analysis included 310 subjects with UTI, bacterial vaginitis, or
Candida vaginitis. Participants with bacterial vaginitis and Candida vaginitis served as the controls. The 310 subjects were randomly selected from the total 966 subjects. A series of contingency tables (2 x 2) was constructed to calculate the sensitivity, specificity, positive predictive value, and negative predictive power for each symptom and dipstick test using the three culture levels as the standard.
Clinical Implications: The findings support continued use of telephone triage, diagnosis, and treatment of UTI because of the high sensitivity, specificity, positive predictive value, and negative predictive value. A urine culture should not be necessary to validate diagnosis if all symptoms are present. The error that would result from this practice would not have been avoided even if physical examination, urine dipstick, and urine culture were used in diagnostic assessment. Physical examination and dipstick analysis are more valuable to rule out UTI than to confirm diagnosis UTI. The delay of 24-48 hours to receive urine culture results to validate a diagnosis or begin treatment can be avoided. The cost of unnecessary diagnosis testing can be avoided by using the symptom cluster of frequency, urgency, and continued urge to void as a diagnostic tool.
Description
Keywords
UTI diagnosis, Urinary Tract Infection