Are Urinalyses Used Inappropriately in the Diagnosis of Urinary Tract Infections?

BACKGROUND: One of the most readily available and cost effective tests in the diagnosis of urinary tract infections (UTI) is the urinalysis. Problems arise when antibiotic treatment is initiated in a patient who does not display typical signs and symptoms of UTI and for whom a urinalysis was obtained for other reasons. METHODS: This was a retrospective observational study carried out on 1000 patients with positive urine nitrite. Medical records were identified with subsequent analysis of urine culture and symptomatology. Recorded and analyzed data included: age, sex, location (emergency room (ER) or hospital ward), findings on urinalysis (pH, presence of leukocyte esterase(LE), epithelial cells, bacteria, and white blood cells (WBCs)) and antibiotic treatment. RESULTS: Of these 1000 patients with positive nitrite, we excluded 815 patients (81 had missing data, 466 met exclusion criteria and 268 had symptomatic UTI). 185 were found to not have any symptoms of a UTI. Inappropriate antibiotic treatment occurred in 108/185 patients (58.4%) and was significantly associated with greater amounts of bacteria and WBCs in the urinalyses (P = 0.008 and P = 0.029, respectively). It was also significantly more likely to occur in the ER than the hospital wards (92/147 treated in the ER vs. 16/37 treated on the hospital wards, P = 0.033). There was no significant association between antibiotic treatment and age, sex, urine pH, urine LE, and urine epithelial cell amounts (P > 0.05). Urine cultures were not obtained in 69.7% of patients. A positive urine culture was significantly associated with inappropriate antibiotic treatment (P = 0.0006). The two most common presenting complaints were psychiatric complaints (21.6%) and vaginal bleeding (14.6%). CONCLUSION: Urinalysis can be an invaluable diagnostic tool, but must be used and interpreted appropriately. There is a misperception that pyuria with bacteriuria defines UTI. However, positive results on a urinalysis alone in an asymptomatic patient is not enough to diagnose a UTI, and antibiotic treatment is only indicated in specific circumstances as outlined by IDSA guidelines for the treatment of asymptomatic bacteriuria. Further education targeting appropriate interpretation of urinalyses and IDSA guidelines is needed to decrease the unnecessary use of antibiotics. DISCLOSURES: All authors: No reported disclosures.