Diagnostic and antibiotic stewardship lessons: an outpatient assessment of symptomatic reflex urinalysis ordering accuracy using an electronic best-practice alert.

Background: It is not well known how reliably clinicians order reflex urinalysis to microscopy and culture (rUA-cx) for outpatient urinary tract infection (UTI) workup. Antibiotic appropriateness cannot be fully appreciated until the prevalence of UTIs and asymptomatic bacteriuria (ASB) are realized.

Objective: This quality improvement study has two major aims, first to determine UTI symptom accuracy for rUA-cx ordering and second, to confirm UTI and ASB cases by integrating rUA-cx and cascaded urinalysis results. Antibiotic utilization and diagnostic coding were secondarily linked to UTIs and ASB.

Methods: An electronic best-practice alert informed the ordering of two rUA-cx options: symptomatic- rUA-cx specifically for dysuria, frequency, urgency, costovertebral pain, suprapubic pain or fever versus non-specific-rUA-cx for vague complaints. UTI symptoms were verified by chart review. Confirmed UTI was defined as a significant culture with UTI symptoms and ASB as a significant culture without UTI symptoms.

Results: rUA-cx (2065) were prospectively collected over 6 months from female patients at risk for uncomplicated UTIs. Symptomatic-rUA-cx and non-specific-rUA-cx were associated with UTI symptoms for 53% (809/1527) and 20% (107/538), respectively. Overall, 44% (916/2065) of all rUA-cx had UTI symptoms. rUA-cx were overordered by a factor of 9 (2065/225) for every confirmed UTI. The UTI-to-ASB relative ratio was 2.6 (225/86). Regarding UTI-relevant antibiotics, 39% (214/553) were appropriately associated with UTI whereas only 22% (74/339) of inappropriate antibiotics were captured by the ASB definition, underestimating the problem 4-fold.

Conclusions: UTI and ASB remain challenging to categorize despite a meticulous method that applied acceptable criteria.