Evaluating the Impact of a Urinalysis to Reflex Culture Process Change in the Emergency Department at a Veterans Affairs Hospital

Interventions

After physician education, an ED process change was implemented on October 3, 2017. This process change involved the creation of new order sets in the EHR that allowed clinicians to order a UA only, a UA with culture that would be cancelled by laboratory personnel if the UA did not result in > 5 WBC/HPF, and a UA with culture designated as do not cancel, where the UC was processed regardless of the UA results. The scenarios in which the latter option was considered appropriate were listed on the ordering screen and included pregnancy, a genitourinary procedure with necessary preoperative culture, and neutropenia.

Measurements

Postimplementation, all UAs were reviewed and grouped as follows: (1) positive UA with subsequent UC; (2) negative UA, culture cancelled; (3) only UA ordered (no culture); or (4) do not cancel UC ordered. Of the UAs that were analyzed, the following data were collected: demographics, comorbidities, concurrent medications for benign prostatic hyperplasia (BPH) and/or overactive bladder (OAB), documented allergies/adverse drug reactions to antibiotics, date of ED visit, documented UTI signs/symptoms (defined as frequency, urgency, dysuria, fever, suprapubic pain, or altered mental status in patients unable to verbalize urinary symptoms), UC results and susceptibilities, number of UCs repeated within 7 days after initial UA, requirement of antibiotic for UTI within 7 days of initial UA, antibiotic prescribed, duration of antibiotic therapy, and outpatient visits, ED visits, or need for hospital admission within 7 days of the initial UA for UTI-related symptoms. Other relevant UA and UC data that could not be obtained from the EHR were collected by generating a report using the Veterans Information Systems and Technology Architecture (VistA).

Analysis

Statistical analysis was performed using SAS v9.4. Independent t tests and Fisher exact tests were used to describe difference pre- and postintervention. Statistical significance was considered for P < .05. Based on results from the previous study conducted at this facility in addition to a literature review, it was determined that 92 patients in each group (pre- and postintervention) would be necessary to detect a 15% increase in percentage of patients appropriately treated for a UTI.

Results

There were 684 UAs evaluated from ED visits, 429 preintervention and 255 postintervention. The 255 patients were evaluated for the secondary objective of the study. Of the 255 patients with UAs identified postintervention, 150 were excluded based on the predefined exclusion criteria, and the remaining 105 were compared with the 173 patients from the preintervention group and were included in the analysis for the primary objective (Figure 1).

Patients in the postintervention group were younger than those in the preintervention group (P < .02): otherwise the groups were similar (Table 1). Inappropriate antibiotics for ASB decreased from 10.2% preintervention to 1.9% postintervention (odds ratio, 0.17; P = .01) (Table 2). UC processing despite a negative UA significantly decreased from 100% preintervention to 38.6% postintervention (P < .001) (Table 3). In patients with a negative UA, antibiotic prescribing decreased by 25.3% postintervention, but this difference was not statistically significant.

Postintervention, of 255 UAs evaluated, 95 (37.3%) were positive with a processed UC and 95 (37.3%) were negative with UC cancelled, 43 (16.9%) were ordered as DNC, and 22 (8.6%) were ordered without a UC (Figure 2). Twenty-eight of the 95 (29.5%) UAs with processed UCs did not meet the criteria for a positive UA and were not designated as DNC. When the UCs of this subgroup of patients were further analyzed, we found that 2 of the cultures were positive of which 1 patient was symptomatic and required antibiotic therapy.

Of the 95 patients with a negative UA, 69 (72.6%) presented without any UTI-related symptoms. In this group, there were no reports of outpatient visits, ED visits, or hospital admissions within 7 days of initial UA for UTI-related symptoms. None of the UCs ordered as DNC had a supporting reason identified. Nonetheless, the UC results from this patient subgroup also were analyzed further and resulted in 4 patients with negative UA and positive subsequent UC, 1 was symptomatic and required antibiotic therapy.

Discussion

A simple process change at the Hines VA resulted in benefits related to antimicrobial stewardship without conferring adverse outcomes on patient safety. Both UC processing despite a negative UA and inappropriate antibiotic prescribing for ASB were reduced significantly postintervention. This process change was piloted in the ED where UCs are often included as part of the initial diagnostic testing in patients who may not report UTI-related symptoms but for whom a UC is often bundled with other infectious workup, depending on the patient presentation.

Reflex testing of urine specimens has been described in the literature, both in an exploratory nature where impact of a reflex UC cancellation protocol based on certain UA criteria is measured by percent reduction of UCs processed as well as results of such interventions implemented into clinical practice.^11-13 A retrospective study performed at the University of North Carolina Medical Center evaluated patients who presented to the ED during a 6-month period and had both an automated UA and UC collected. UC processing was restricted to UA that was positive for nitrites, leukocyte esterase, bacteria, or > 10 WBC/HPF. Use of this reflex culture cancellation protocol could have eliminated 604 of the 1546 (39.1%) cultures processed. However, 11 of the 314 (3.5%) positive cultures could have been missed.¹³ This same protocol was externally validated at another large academic ED setting, where similar results were found.¹⁴