The project goal was to standardize procedural antibiotic usage across varied practice sites in a regional healthcare network. We collaborated with multidisciplinary stakeholders in Infectious Disease, Pharmacy, and Nursing leadership to develop a standing order based on the AUA BPS which was approved for use by the Standing Order Committee of our healthcare system [4].

We established selection criteria for high-risk host factors and urological procedures based on the AUA Best Practice Statement on urologic procedures and antimicrobial prophylaxis, as well as the joint Advisory Statement from the AUA and the American Academy of Orthopaedic Surgeons on antibiotic prophylaxis for urological patients with total joint replacements [4, 9]. A visual description of the algorithm is provided in Fig. 1. The algorithm provides a schema for the utilization of prophylactic antibiotics for all patients undergoing higher-risk procedures (e.g., cystoscopy with biopsy or stent removal) and for patients undergoing lower-risk procedures who have patient-specific risk factors for infection. A comprehensive table of procedures and associated risk categories is shown in Appendix Fig. 1a. Our group operationalized the AUA host risk factors as follows: age ≥80 years (advanced age) [3]; body mass index (BMI) ≤18 or most recent serum albumin < 3 g/dL (poor nutritional status); diabetes mellitus or current tobacco use (immunocompromising conditions), and urinary foreign body or joint replacement within two years (presence of exogenous material). Post-void residual bladder volume > 200 mL was also considered an indication for antibiotics due to increased risk of bacteriuria. Patients undergoing low risk urologic procedures, such as urodynamics, with high-risk host factors were deemed suitable candidates for antibiotic prophylaxis.

Flow diagram of antibiotic prophylaxis protocol

The working group selected 1 dose of 3 g of oral fosfomycin as the prophylactic antibiotic of choice. Strengths of fosfomycin include its efficacy across a wide range of gram-positive and gram-negative urinary flora, its ability to achieve bactericidal urinary concentrations following a single oral dose, its favorable side effect profile, and its limited bacterial resistance [10]. Previous evidence supports the use of 3 g of oral fosfomycin as perioperative prophylaxis in patients undergoing endourological procedures [11]. Furthermore, our institutional antibiogram indicated that fosfomycin provides excellent coverage across flora most commonly isolated from collected urine samples.

The protocol was drafted by our working group in March 2017 and approved for use by the health system Standing Order Committee in May 2018. Following staff training and dashboard development, the protocol was lauched across all sites in February 2019.

All patients presenting for an indexed, office-based urologic procedure (Supplementary Table 1) performed by one of the urologic providers in our health system were evaluated by nursing staff. Nursing staff determined the planned procedure and assessed patient risk factors from the electronic medical record to determine if antimicrobial prophylaxis was indicated per protocol. In accordance with our health system’s standards, all patients underwent a urine culture prior to urinary instrumentation and a rectal swab before prostate biopsy to optimize antibiotic prophylaxis. In events where there was a documented allergy to foscomycin or concern for deviation from the protocol, the nursing staff were instructed to have a licensed independent urologic provider review the clinical circumstance and reference the AUA BPS to guide decision-making regarding antimicrobial prophylaxis for the procedure. Otherwise, 3 g of oral fosfomycin was dispensed from the PyxisÒ system in accordance with the health system standing order. Licensed independent urologic providers were responsible for final medication review prior to the closure of the patient clinical encounter and were required to authorize the medication via co-signature within 48 h of the patient visit.

We collaborated with our health system’s joint data analytics team (JDAT) to build a live dashboard using Tableau Software™ (Mountain View, CA) which electronically abstracted data from the EPIC Clarity™ (EPIC Systems™; Verona, WI) electronic medical record system. An image of the dashboard display is shown in Appendix Fig. 2a. Utilizing relevant Current Procedural Terminology (CPT) codes, we abstracted data for all urologic patients undergoing the office-based index procedures across the delivery networks of our health system such as the date of the procedure, the type of procedure, and whether preprocedural antibiotics were administered. We also tracked outcomes within 30 days of the index office-based procedure. These included abnormal urinalysis, positive urine culture, and presence of a febrile urinary tract infection. Febrile urinary tract infections were tracked using retrospective review of electronic medical records, leveraging an algorithm developed by the JDAT team. This algorithm generated a composite variable that identified cases based on a positive urinalysis combined with either documented fever or a clinical diagnosis within the same encounter.

Antibiotic usage rate before and after protocol implementation

The primary outcome measure was defined as the monthly percentage of patients who experienced a post-procedural febrile urinary tract infection within 30 days of the index office-based procedure. A febrile urinary tract infection was defined by either a formal diagnosis from a licensed independent practitioner or the concurrent presence of an abnormal urinalysis and a temperature exceeding 37.5 C during the same clinical encounter. An abnormal urinalysis was defined by either the presenece of nitrites or the presence of bacteria with > 10 white blood cells per high power field.

Secondary outcomes were defined as: the monthly percentage of patients who experienced an abnormal urinalysis (as defined above) without a diagnosis of a febrile UTI, the monthly percentage of patients who received pre-procedural antibiotics, the variation in monthly antibiotic administration frequencies among the five urologic practice sites of our health system, and the practice-specific frequencies of monthly antibiotic administration.

We collated data from our live dashboard and calculated monthly percentages of patients with febrile UTI, monthly percentages of patients with abnormal urinalysis, and monthly antibiotic administration frequencies for our study period. The F-test was used to compare differences in standard deviation.

We utilized interrupted time series analysis (ITS) to estimate the effects of the intervention. ITS is a quasi-experimental design which uses regression techniques to analyze if the data pattern after an intervention differs significantly from pre-intervention trends [12]. ITS techniques have a broad literature basis for the evaluation of healthcare quality improvement programs, and offer the flexibility to assess if changes in the outcomes of interest are attributable to the intervention [13]. We assessed our model for the presence of autocorrelation of residuals by utilizing autocorrelation function (ACF) and partial autocorrelation function (pACF) plots, and Breusch-Godfrey tests up to lag 7. We assessed for stationarity and the presence of a unit root with the use of the augmented Dickey-Fuller test. For the augmented Dickey-Fuller test, results were considered statistically significant if p < 0.1, owing to the low power of the augmented Dickey-Fuller test in situations such as this one with limited data availability [14]. We further explored the suitability of autoregressive integrated moving average (ARIMA)-based regression models utilizing the approach outlined by Box and Jenkins [15]. Final ITS models were ordinary least squares models with Newey-West standard errors. All other tests were considered statistically significant if p < 0.05. Data analysis was conducted in R v4.0.2 (R Foundation for Statistical Computing™, Vienna, Austria) with use of the Tidyverse™ and Forecast™ packages [16, 17].

The office-based urologic procedure antibiotic prophylaxis standing order was approved by our health system Standing Order Committee. We carefully followed our institution’s guidance for determination of institutional review board (IRB) exemption, and it was determined that this quality improvement initiative was not subject to protocol approval by the IRB.