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

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.

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.

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.

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.

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