Overtreating UTIs: Walk Softly and Carry a Dipstick

A Best Evidence Review

Charles P. Vega, MD


September 27, 2012

In This Article

Best Evidence Review of Symptom-Based Diagnosis of Urinary Tract Infection in Women

The Study

Mishra B, Srivastava S, Singh K, Pandey A, Agarwal J. Symptom-based diagnosis of urinary tract infection in women: are we over-prescribing antibiotics? Int J Clin Pract. 2012;66:493-498

The Background

There are approximately 8 million clinical encounters for urinary tract infection (UTI) in the United States each year, but there is also evidence that UTI may be overdiagnosed and overtreated. Mishra and colleagues' study demonstrates that less than one half of sexually active women presenting with UTI symptoms actually had a culture-confirmed UTI. No individual symptom was strongly predictive of UTI, but urgency and burning during micturition were sensitive markers of UTI. Adding the presence of pyuria to these symptoms increased the specificity of the diagnostic tool. UTI should generally not be diagnosed on the basis of patient history alone.

Scope of the Problem

UTI is generally considered to be a highly bothersome but benign condition. With appropriate therapy, the duration of symptoms is short, and complications are rare. However, given the high prevalence of UTI and its effect on the use of healthcare resources, it should be considered both an important individual and public health issue.

UTI results in nearly 7 million medical office visits each year in the United States, as well as 1 million visits to the emergency department.[1] UTI also is responsible for approximately 100,000 hospitalizations per year. It is far more common among women than men, with approximately 1 in 3 women experiencing a UTI requiring antimicrobial therapy by 24 years of age. The lifetime prevalence of UTI among women is 40%-50%, and the estimated annual cost of community-acquired UTI in the United States is $1.6 billion.

Asymptomatic Bacteriuria

Compounding the overall impact of UTI is an increasing understanding of the wide prevalence of asymptomatic bacteriuria. Asymptomatic bacteriuria is again particularly prevalent among women and is positively associated with age; one study showed an overall prevalence of 18.2% and 6% in older women and men, respectively.[2] Institutionalization is also associated with high rates of asymptomatic bacteriuria, with a prevalence of 23.5% in this study.[2]

Asymptomatic bacteriuria should generally not be treated, even in patients with chronic indwelling catheters or a history of diabetes or spinal cord injury.[3] The exceptions are pregnant women and patients undergoing procedures to the genitourinary tract, who should be treated.

Treating Symptomatic UTI

Symptomatic UTI should be treated with antimicrobials, and current guidelines for the management of uncomplicated UTI recommend a 3-day course of trimethoprim/sulfamethoxazole or a fluoroquinolone or 7 days of treatment with nitrofurantoin.[4]

However, there is a tremendous difference between these standards and community practice. In general, physicians overprescribe the wrong antibiotics for a longer duration than is necessary. In a recent study of adult inpatients, one third of those with asymptomatic enterococcal bacteriuria received antibiotics despite recommendations to the contrary.[5] The rate of subsequent UTIs due to enterococcus was only 2.1%. In another study of an older population of hospitalized patients, 64% of those with bacteriuria and no genitourinary symptoms were treated with antibiotics.[6]

Community treatment of UTI also frequently strays from current guidelines. In a study from France, where the guidelines for the management of UTI were changed in 2008, only 20% of prescriptions in 2010 were adherent to these guidelines.[7] 71% of the antibiotic choices were considered inappropriate, with strong overuse of fluoroquinolones for uncomplicated UTI. The economic cost of each inappropriate prescription averaged €7.4.

Adherence to treatment guidelines is poor in the United States as well. Despite guidelines that account for antimicrobial resistance patterns, there has been no change in the use of trimethoprim/sulfamethoxazole and there has been a concomitant steady and significant increase in prescriptions for ciprofloxacin.[8] In a study based in Arizona, the rate of appropriate management of uncomplicated UTI was only 25%.[9] 39% of patients in this research received a prolonged course of antibiotics without a clinical indication for longer treatment.

Even the diagnosis of uncomplicated UTI is more complex than many physicians realize. In a study of adult women with urinary symptoms, less than one half were found to have UTI on the basis of urine culture results.[10] None of the common symptoms of UTI achieved a specificity over 50% in the diagnosis of UTI.

Therefore, UTI may be both overdiagnosed and overtreated. Mishra and colleagues' study further evaluates this issue and attempts to develop an algorithm to help physicians accurately identify and treat uncomplicated UTI in an office-based practice.