Original Paper

Diagnostic Utility of Urinalysis in Detecting Urinary Tract Infection in Hemodialysis Patients
Rajiv Vij^{a, b}, Swetha Nataraj^{a, c}, Aldo J. Peixoto<sup>a, d

a</sup>Medical Service, VA Connecticut Healthcare System, West Haven, Conn.,
^bInternal Medicine Residency Program, Norwalk Hospital, Norwalk, Conn.,
^cInternal Medicine Residency Program, University of Connecticut School of Medicine, Farmington, Conn., and
^dSection of Nephrology, Yale University School of Medicine, New Haven, Conn., USA

Address of Corresponding Author

Nephron Clin Pract 2009;113:c281-c285 (DOI: 10.1159/000235243)

  Key Words

• Pyuria
• Urinary tract infections
• Renal dialysis
• Diagnosis
• Sensitivity and specificity
• Predictive value of tests

  Abstract

Background/Aims: Urinary tract infections (UTIs) are common in dialysis patients. The diagnostic accuracy of pyuria in this population has been incompletely evaluated and is the object of this study. Methods: We assembled a historical cohort of male hemodialysis patients with urinalysis and urine microbiology data. Each matched pair of urinalysis and urine culture was considered as the unit of measurement. We evaluated the diagnostic performance and plotted receiver operating characteristic curves for different cutoff values of pyuria [>5, >10, >50, >100 white blood cells per high-power field (WBC/HPF)]. Results: Of 134 patients, 97 had at least one matched urinalysis and urine culture, providing 224 pairs for analysis. The prevalence of pyuria was 65 and 51% using cutoff values of >5 or >10 WBC/HPF, respectively. The presence of pyuria (>5 WBC/HPF) had a sensitivity between 82 and 89% and specificity of between only 53 and 55%. The presence of nitrites on dipstick had high specificity (94%) but very poor sensitivity (14-20%). All other urinary indices had poor diagnostic performance in the identification of a positive urine culture. Conclusion: In the absence of adequate specificity and positive predictive value in dialysis patients, urine culture should be obtained to guide further treatment.

Copyright © 2009 S. Karger AG, Basel

  Author Contacts

Aldo J. Peixoto, MD
Medical Service - 111, 950 Campbell Avenue
West Haven, CT 06516 (USA)
Tel. +1 203 932 5711, ext. 5907, Fax +1 203 937 3425
E-Mail aldo.peixoto@yale.edu

  Article Information

Received: November 30, 2008
Accepted: January 27, 2009
Published online: September 3, 2009
Number of Print Pages : 5
Number of Figures : 1, Number of Tables : 3, Number of References : 9