Alterations in chromosomal genes nfsA, nfsB, and ribE are associated with nitrofurantoin resistance in Escherichia coli from the United Kingdom

Antimicrobial resistance in enteric or urinary Escherichia coli is a risk factor for invasive E. coli infections. Due to widespread trimethoprim resistance amongst urinary E. coli and increased bacteraemia incidence, a national recommendation to prescribe nitrofurantoin for uncomplicated urinary tract infection was made in 2014. Nitrofurantoin resistance is reported in <6% urinary E. coli isolates in the UK, however, mechanisms underpinning nitrofurantoin resistance in these isolates remain unknown. This study aimed to identify the genetic basis of nitrofurantoin resistance in urinary E. coli isolates collected from north west London and then elucidate resistance-associated genetic alterations in available UK E. coli genomes. As a result, an algorithm was developed to predict nitrofurantoin susceptibility. Deleterious mutations and gene-inactivating insertion sequences in chromosomal nitroreductase genes nfsA and/or nfsB were identified in genomes of nine confirmed nitrofurantoin-resistant urinary E. coli isolates and additional 11 E. coli isolates that were highlighted by the prediction algorithm and subsequently validated to be nitrofurantoin-resistant. Eight categories of allelic changes in nfsA, nfsB, and the associated gene ribE were detected in 12412 E. coli genomes from the UK. Evolutionary analysis of these three genes revealed homoplasic mutations and explained the previously reported order of stepwise mutations. The mobile gene complex oqxAB, which is associated with reduced nitrofurantoin susceptibility, was identified in only one of the 12412 genomes. In conclusion, mutations and insertion sequences in nfsA and nfsB were leading causes of nitrofurantoin resistance in UK E. coli . As nitrofurantoin exposure increases in human populations, the prevalence of nitrofurantoin resistance in carriage E. coli isolates and those from urinary and bloodstream infections should be monitored.

194. Progression of an Uncomplicated Urinary Tract Infection Among Female Patients with Susceptible and Non-Susceptible Urine Isolates: Findings from an Integrated Delivery Network

Background Uncomplicated urinary tract infection (uUTI) is often treated empirically without antibiotic (AB) susceptibility testing; however, antimicrobial-resistant bacteria could lead to suboptimal treatment and progression to complicated UTI (cUTI). We examined the likelihood of uUTI progression to cUTI in patients with susceptible and non-susceptible uropathogens. Methods We performed a retrospective cohort study using data from a large Mid-Atlantic US integrated delivery network’s electronic health records from July 1, 2016 to March 31, 2020. Patients included were female, aged ≥ 12 years with incident uUTI (diagnosis code or urine culture), and given an oral AB ± 5 days of diagnosis and ≥ 1 antibiotic susceptibility test. The primary outcome was progression to cUTI, defined as: new fever, nausea, or vomiting, in addition to uUTI symptoms; or receipt of intravenous antibiotic 3–28 days after index uUTI. Probability of progression to cUTI was assessed comparing patients with non-susceptible and susceptible isolates, with 1:1 propensity score matching. Patients retained for analysis had a nonzero predicted probability of being in the case and control group and were retained for analysis only if there were patients in the mirror group with similar propensity scores. Data were analyzed with logistic regression. Sensitivity analyses were performed to test the robustness of the primary analysis (Table). Results A total of 2565 patients were included: 1030 (40.2%) had non-susceptible isolates and 1535 (59.8%) had susceptible isolates. Mean age was 43.5 years and 59.5% of the cohort was White. After propensity score matching, patients with non-susceptible isolates were more than twice as likely to progress to cUTI versus patients with sensitive isolates (10.7% versus 4.9%; odds ratio, 2.35; p &lt; 0.001; Figure). In sensitivity analyses, patients with non-susceptible isolates remained significantly more likely to progress to cUTI (p ≤ 0.009), excluding those receiving fluoroquinolones only (Table). Figure. Probability of progression to cUTI Table. Sensitivity analyses of the probability of uUTI progressing to cUTI in patients with non-susceptible versus susceptible isolates (matched population) Conclusion Patients with uUTI and AB-resistant isolates were significantly more likely to progress to cUTI than those with susceptible isolates. This finding highlights the need for greater understanding of antimicrobial resistance and has implications for the clinical management of uUTI. Disclosures Jason Shafrin, PhD, Precision Medicine Group (Employee, Former employee of Precision Medicine Group, which received funding from GlaxoSmithKline plc. to conduct this study) Alen Marijam, MSc, GlaxoSmithKline plc. (Employee, Shareholder) Ashish V. Joshi, PhD, GlaxoSmithKline plc. (Employee, Shareholder) Fanny S. Mitrani-Gold, MPH, GlaxoSmithKline plc. (Employee, Shareholder) Katie Everson, MSc, Precision Medicine Group (Employee, Employee of Precision Medicine Group, which received funding from GlaxoSmithKline plc. to conduct this study) Rifat Tuly, MPH, Precision Medicine Group (Employee, Employee of Precision Medicine Group, which received funding from GlaxoSmithKline plc. to conduct this study) Peter Rosenquist, MSc, Precision Medicine Group (Employee, Employee of Precision Medicine Group, which received funding from GlaxoSmithKline plc. to conduct this study) Michael Gillam, MD, MedStar Health (Employee, Employee of MedStar Health and received funding from GlaxoSmithKline plc. through Precision Medicine Group to conduct this study) Maria Elena Ruiz, MD, Nothing to disclose

1415. Allergies to Antimicrobial Agents Among US Females with Uncomplicated Urinary Tract Infection

Background Uncomplicated urinary tract infections (uUTI) are generally treated empirically with antibiotics. However, antibiotic (AB) allergies limit the available oral treatment options for some patients. We assessed the proportion of self-reported AB allergies among US females with uUTI. Methods We performed a cross-sectional survey of US females ≥ 18 years of age with a self-reported urinary tract infection (UTI) in the 60 days prior to participation and a prescription of oral AB. Participants were further screened for evidence of a complicated urinary tract infection and, after exclusions, participants with a uUTI completed an online questionnaire about their most recent episode. Participants were from the Northeast (20%), Midwest (44%), South (20%), and West (16%) US. Descriptive self-reported allergy data were stratified into subgroups by whether the participant had recurrent UTI (defined as ≥ 2 uUTIs in the past 6 months or ≥ 3 uUTIs in past 12 months including index UTI), the number of different ABs given for the index episode (1, 2, ≥ 3), and whether the treatment was clinically appropriate according to Infectious Diseases Society of America uUTI guidelines. Results Overall, 375 female participants completed the questionnaire. The most commonly prescribed ABs for participants’ most recent uUTI were trimethoprim-sulfamethoxazole (TMP-SMX; 38.7%), ciprofloxacin (22.7%), and nitrofurantoin (18.9%) (Table 1). Most participants received only 1 AB for their uUTI (62.7%) and the majority were classified as having a non-recurrent uUTI (56.5%). No AB allergies were reported for most participants (69.3%); overall, 24.0% reported 1 AB allergy and 6.7% reported ≥ 2. A higher proportion of participants reported ≥ 2 allergies in the recurrent uUTI, ≥ 3 AB, and multiple AB subgroups (Table 2). The most common allergy was to TMP-SMX (15.7%), followed by amoxicillin-clavulanate (8.3%) and ciprofloxacin (5.3%) (Table 2). Similar allergy trends were seen across subgroups, except higher rates of ciprofloxacin allergy were seen in participants given multiple ABs (Table 2). Table 1. Antibiotics used to treat most recent uUTI Table 2 . Frequency of antibiotic allergies across cohort subgroups Conclusion AB allergies were relatively frequent in this uUTI cohort and the most common allergy was to TMP-SMX, which was the most prescribed AB. Allergies to ABs reduce the available treatment options for uUTI in some patients. Disclosures Jeffrey Thompson, PhD, Kantar Health (Employee, Employee of Kantar Health, which received funding from GlaxoSmithKline plc. to conduct this study) Alen Marijam, MSc, GlaxoSmithKline plc. (Employee, Shareholder) Fanny S. Mitrani-Gold, MPH, GlaxoSmithKline plc. (Employee, Shareholder) Jonathon Wright, BSc, Kantar Health (Employee, Employee of Kantar Health, which received funding from GlaxoSmithKline plc. to conduct this study) Ashish V. Joshi, PhD, GlaxoSmithKline plc. (Employee, Shareholder)

1429. Real-World Study of Patients with Uncomplicated Urinary Tract Infection in the United States: High-Risk Comorbid Conditions and Burden of Illness

Background Urinary tract infections (UTIs) are associated with significant morbidity and economic burden, particularly in the elderly and patients with comorbidities. We used real-world data (RWD) to assess healthcare resource use (HRU) and costs in patients with uncomplicated UTI (uUTI) and high-risk comorbid conditions in the US. Methods This was a retrospective cohort study (IBM MarketScan RWD, commercial/Medicare Supplemental claims January 1, 2014–December 31, 2017) of females ≥ 12 years of age with uUTI who had an oral antibiotic prescription ± 5 days of uUTI diagnosis (index date) and continuous health-plan enrollment for ≥ 1 year pre-/post index date. Five high-risk cohorts and matched-control cohorts (baseline age, region) were identified: controlled type 2 diabetes (T2D), mild/moderate chronic kidney disease (CKD), recurrent UTI (rUTI), elderly (ELD), and postmenopausal (PMP) (Table 1). Sample sizes were balanced via random match selection (1:5 case:control). uUTI-related HRU and costs were compared between cases and controls (index episode/1-year follow-up) using multivariable generalized linear models. Table 1. Cohort assignment for high-risk cohorts and controls Results Of 339,100 patients with uUTI, case/control cohorts comprised T2D, n=15,423/n=77,115; CKD, n=1041/n=5205; rUTI, n=7937/n=39,685; ELD, n=23,666/n=118,330; and PMP, n=105,608/n=211,216 patients. HRU trends across cohorts varied. During 1-year followup, outpatient visits were significantly different for cases versus controls in the T2D, rUTI, and PMP cohorts (p ≤ 0.0079), with higher case than control values in the rUTI and PMP cohorts; pharmacy claims were significantly higher for rUTI, ELD, and PMP cases, and inpatient visits were significantly higher for ELD and PMP cases, versus controls (all p &lt; 0.0001; Table 2). Adjusted total uUTI-related costs (emergency room + outpatient + pharmacy) were significantly different (p &lt; 0.0001) for cases versus controls at index episode and during follow-up in all cohorts except CKD: case values were higher than controls at index episode and during follow-up in the T2D cohort, and during follow-up in the rUTI and ELD cohorts (Table 3). Table 2. uUTI-related HRU* for cases versus controls according to high-risk cohort Table 3. uUTI-related costs* for cases versus controls according to high-risk cohort Conclusion Females in some high-risk case cohorts had higher uUTI-related HRU and costs versus controls. Further studies of relationships between comorbidities and uUTI burden are needed. Disclosures Madison T. Preib, MPH, STATinMED Research (Employee, Former employee of STATinMED Research, which received funding from GlaxoSmithKline plc. to conduct this study) Alen Marijam, MSc, GlaxoSmithKline plc. (Employee, Shareholder) Fanny S. Mitrani-Gold, MPH, GlaxoSmithKline plc. (Employee, Shareholder) Daniel C. Gibbons, PhD, GlaxoSmithKline plc. (Employee, Shareholder) Xiaoxi Sun, MA, STATinMED Research (Employee, Employee of STATinMED Research, which received funding from GlaxoSmithKline plc. to conduct this study) Christopher Adams, MPH, STATinMED Research (Employee, Employee of STATinMED Research, which received funding from GlaxoSmithKline plc. to conduct this study) Ashish V. Joshi, PhD, GlaxoSmithKline plc. (Employee, Shareholder)

76. Uncomplicated Urinary Tract Infections in the Multi-resistance Era: Is It Time of Microbiologic Diagnosis? An Observational Study in Buenos Aires City

Background Uncomplicated urinary tract infection (uUTI) is one of the main causes of antibiotics prescription in outpatient setting. Current recommendations, based on studies from pre-antimicrobial resistance era, suggest that diagnosis of uUTI can be made based on clinical symptoms and that urine analysis leads only to a minimal increase in diagnostic accuracy. We analyzed urine cultures (UC) from patients with clinical diagnosis. Methods Prospective and observational study carried out in an Emergency Department during August 2016 to August 2017. Women older than 15 years with 2 or more classic symptoms of uUTI and the absence of vaginal discharge and irritation were included. Those with complicated and recurrent urinary tract infection (UTI) were excluded. Urine cytology and UC were performed in all episodes. A bivariate and multivariate analysis was performed considering the probability of having a positive urine culture according to the different symptomatology variables. Results We enrolled 208 patients, with a median age of 25 (14-68 years). Previous UTI 6 (2.9%), previous antibiotic (last 3 months) 20 (9.6%). Inflammatory cytology 173 (83.2%), positive UC 109 (52.4%), cystitis 155 (74.5%). Symptoms: dysuria 154 (74%), frequency 111 (53.4%), tenesmus 97 (46.6%), fever 78 (37.5%), hematuria 43 (20, 7%), hypogastric pain 128 (61.5%), back pain 84 (40.4%). Combinations of 3 or more classic symptoms occurred in 52 (25%) episodes. The most frequent association was dysuria, frequency and tenesmus. No statistically significant association was found either in the bivariate or multivariate analysis in relation to presenting positive UC (Tables 1 and 2). Conclusion The results show that almost 50% of the patients with a clinical diagnosis of UTI had a negative urine culture. We consider it necessary to rethink the prescription of antibiotics without microbiological confirmation in the first episode of uUTI as a strategy to reduce inappropriate use of antibiotics. Disclosures All Authors: No reported disclosures

1428. Increased Consumption of Pivmecillinam in Primary Care for Uncomplicated Urinary Tract Infection (uUTI) Is Not Associated With Increased Resistance Rates

Background The evolution of antibiotic resistance in Escherichia coli (E. coli) hampers the treatment of UTIs, mirroring the global public health concerns around antimicrobial resistance. Pivmecillinam, an oral prodrug of mecillinam (a β-lactam antibiotic), is used as first-line treatment for uUTIs in Denmark. Here, we examine the use of, and the prevalence of resistance to, mecillinam in Denmark in the primary care setting. Methods Nationwide data on the use of and resistance to pivmecillinam (reported as its active form, mecillinam) was extracted and examined from the Danish Integrated Antimicrobial Resistance Monitoring and Research Programme (DANMAP) 2019 report (www.danmap.org). Prevalence estimates of resistance reported by DANMAP 2019 were obtained from the Danish Microbiology Database (MiBA). Results In 2019, pivmecillinam accounted for about 27% of penicillins and 75% of penicillins with extended spectrum consumed in primary healthcare in Denmark. Pivmecillinam usage has increased primarily due to changes in recommendations for the treatment of uUTIs. Between 2010 and 2019, pivmecillinam usage in Denmark increased by 45% from 1.67 to 2.43, defined as daily doses per 1,000 inhabitants per day. In 2019, analysis of 83,850 urinary isolates from patients in the primary care setting with E. coli revealed a 5.3% resistance rate to mecillinam. Time-trend analysis using data from a 10-year period showed a small but significant decrease from the 5.5% resistance rate recorded in 2010 (p=0.001). In general, in spite of increasing use in Denmark, the development of resistance to pivmecillinam has remained low. In fact, a slight decline in pivmecillinam resistance was observed over the past decade. Conclusion Despite the rising number of UTIs and the increasing use of pivmecillinam for uUTI in Denmark, over the past decade, the development of resistance to pivmecillinam remains low. Disclosures Anne Santerre Henriksen, MS, Advanz (Consultant)Shionogi BV (Consultant)UTILITY Therapeutics (Consultant)

1422. Real-World Study of the Effects of Inappropriate or Suboptimal Treatment on the Burden of Illness Among Patients with Uncomplicated Urinary Tract Infection and High-Risk Comorbid Conditions in the United States

Background Urinary tract infections (UTIs) are associated with significant morbidity and economic burden. Nitrofurantoin (NFT) and fosfomycin are among the first-line treatments for uncomplicated UTI (uUTI) recommended by Infectious Diseases Society of America (IDSA) 2011 guidance. We used real-world data (RWD) to assess patterns of appropriate and optimal (AP&OP) and inappropriate or suboptimal (IA/SO) antibiotic (AB) prescribing (RX), and related healthcare resource use (HRU) and costs, in US uUTI patients with high-risk comorbid conditions. Methods This was a retrospective cohort study of RWD (IBM MarketScan, commercial/Medicare Supplemental claims January 1, 2014–December 31, 2017) in females ≥ 12 years of age with uUTI, who had an oral AB prescription ± 5 days of uUTI diagnosis (index date) and continuous health-plan enrollment ≥ 1 year pre-/post-index date. Patients were stratified into high-risk cohorts (Table 1) and by AB RX (AP&OP and IA/SO) during first uUTI episode (within 28 days of index). AP&OP RX followed IDSA guidance, IA RX did not; SO RX was considered a proxy for treatment failure (e.g., AB switch or a second UTI diagnosis [acute care setting] in index episode). Sample size was balanced via random match selection, AP&OP:IA/SO ratio 1:5 (age and region). uUTIrelated HRU and costs were compared between cohorts (at index episode and 1-year follow-up) via multivariable analysis. Table 1. High-risk cohorts identified in the study Results IA/SO AB RX was highest in the elderly cohort (94.3%, likely influenced by renal impairment/no NFT RX in this group) and &gt; 90% in other cohorts; AP&OP AB RX was highest in the postmenopausal cohort (9.0%). IA/SO AB RX in all cohorts was associated with significantly higher uUTI-related HRU (outpatient visits and pharmacy claims) per index episode/during follow-up versus AP&OP AB RX (p ≤ 0.0237, Table 2). IA/SO AB RX in all cohorts was associated with significantly higher adjusted total costs per index episode/during follow-up versus AP&OP AB RX (p &lt; 0.05; Table 3). Table 2. uUTI-related HRU* per patient according to high-risk cohort and stratified by AB RX Table 3. uUTI-related costs* per patient according to high-risk cohort and stratified by AB RX Conclusion Over 90% of females in each high-risk cohort identified had IA/SO AB RX (outside IDSA 2011 guidance for uUTI treatment), leading to high HRU and cost burden. This suggests an unmet need for uUTI symptom relief, new treatments, training, and improved RX practices in the US and, furthermore, a need for additional research in this area. Disclosures Madison T. Preib, MPH, STATinMED Research (Employee, Former employee of STATinMED Research, which received funding from GlaxoSmithKline plc. to conduct this study) Alen Marijam, MSc, GlaxoSmithKline plc. (Employee, Shareholder) Fanny S. Mitrani-Gold, MPH, GlaxoSmithKline plc. (Employee, Shareholder) Daniel C. Gibbons, PhD, GlaxoSmithKline plc. (Employee, Shareholder) Xiaoxi Sun, MA, STATinMED Research (Employee, Employee of STATinMED Research, which received funding from GlaxoSmithKline plc. to conduct this study) Christopher Adams, MPH, STATinMED Research (Employee, Employee of STATinMED Research, which received funding from GlaxoSmithKline plc. to conduct this study) Ashish V. Joshi, PhD, GlaxoSmithKline plc. (Employee, Shareholder)

1434. Treatment Patterns, Healthcare Resource Use, and Associated Costs in Females with Uncomplicated Urinary Tract Infection in the United States

Background Urinary tract infections (UTIs) disproportionately affect women and are a substantial burden on healthcare systems. We assessed the effect of antibiotic (AB) switching on UTI recurrence, healthcare resource use (HRU), and related costs among adolescent and adult females in the US with uncomplicated UTIs (uUTIs). Methods This retrospective cohort study used US Optum claims data (United Healthcare, January 1, 2013–December 31, 2018). Eligible patients were females ≥ 12 years of age with an acute uUTI diagnosis at outpatient or emergency department (ED) visit (index date) and an oral AB prescription within ± 5 days of index. Patients with recurrent UTIs (rUTIs), defined as 2 UTI diagnoses (including index) in 6 months or ≥ 3 UTI diagnoses (including index) in 12 months, were included; those with complicated UTI were excluded. Patients were assigned to two groups: AB switch (≥ 2 filled prescriptions of different AB within 28 days post index [uUTI episode]) and no AB switch. Results In 5870 eligible patients (mean age 44.5 years; 76.6% White), ciprofloxacin (CIP; 38.6%), nitrofurantoin (NFT; 31.4%), and trimethoprim-sulfamethoxazole (TMP-SMX; 25.6%) were the most commonly prescribed first-line ABs at index, and 567 (9.7%) patients switched AB. CIP was switched to NFT and TMP-SMX in 2.0% and 1.7% of patients, respectively. NFT was switched to CIP and TMP-SMX in 2.6% and 1.5% of patients, respectively. TMP-SMX was switched to CIP and NFT in 3.0% and 2.4% of patients, respectively. During index visit, the AB switch group had higher mean ambulatory care and pharmacy claims (both p &lt; 0.001), and higher total mean HRU costs (&2186.4) per patient compared with the no switch group (&1508.8; p = 0.011). More patients had rUTI in the AB switch group (18.9%) versus the no switch group (14.2%; p &lt; 0.001), and more had ED visits in the AB switch group than the no switch group (p &lt; 0.0001) (Table 1). During follow-up, the AB switch group had a higher mean number of uUTI episodes per patient (p &lt; 0.001; Table 1), and more patients had UTI-related ED visits (10.8%) compared with the no switch group (7.7%; p = 0.010; Table 2). Table 1. Primary outcomes of uncomplicated UTI outpatients during January 1, 2013–December 31, 2018, stratified by any switch in AB use during index episode Table 2. Primary outcomes of uncomplicated UTI outpatients during January 1, 2013–December 31, 2018, stratified by any switch in AB use during 12-month follow-up Conclusion US females with uUTI who switched AB had more rUTI cases and increased overall costs and HRU compared with those who did not switch AB, suggesting an unmet need for improved prescribing practices. Disclosures Rena Moon, MD, Premier Applied Sciences, Premier Inc. (Employee) Alen Marijam, MSc, GlaxoSmithKline plc. (Employee, Shareholder) Fanny S. Mitrani-Gold, MPH, GlaxoSmithKline plc. (Employee, Shareholder) Daniel C. Gibbons, PhD, GlaxoSmithKline plc. (Employee, Shareholder) Alex Kartashov, PhD, Premier Applied Sciences, Premier Inc. (Employee) Ning Rosenthal, MD, Premier Applied Sciences, Premier Inc. (Employee, Shareholder) Ashish V. Joshi, PhD, GlaxoSmithKline plc. (Employee, Shareholder)

197. Healthcare Resource Utilization and Costs Associated with Inappropriate and Suboptimal Prescribing of Antibiotics for Uncomplicated Urinary Tract Infection in the United States

Background Despite well-established guidelines for urinary tract infection (UTI) treatment, prescribing practices vary. We examined the association between inappropriate (IA) or suboptimal (SO) antibiotic (AB) prescribing (RX) and hospitalization, healthcare resource use (HRU), and costs among patients with uncomplicated UTI (uUTI) in the US. Methods This retrospective cohort study used linked Premier Healthcare/Optum claims data from female outpatients (≥ 12 years old) with a uUTI diagnosis (January 1, 2013 to December 31, 2018). Patients with complicated UTIs (eg, urological abnormalities, medications/procedures associated with complicated UTI, or intravenous AB receipt at index) were excluded. HRU and costs between patients with IA/SO and appropriate and optimal (AP&OP) AB RX (defined in Table 1) were assessed from Optum claims data during index episode (within 28 days of index) and 12-month follow-up. Table 1. Definitions of appropriateness of AB RX Results Of 5870 patients, 1856 (31.6%) had IA and 1255 (21.4%) had SO AB RX. Patients with IA/SO AB RX (47.1%) were older and more likely to have a Charlson Comorbidity Index score &gt; 0 than those with AP&OP AB RX (52.9%; Table 2). During index episode, mean ambulatory care and pharmacy claims were significantly higher for IA/SO versus AP&OP AB RX (8.0 vs 6.3, 3.3 vs 2.6, respectively; p &lt; 0.01), and total HRU cost per patient was higher for IA/SO (&2616) versus AP&OP AB RX (&649; p &lt; 0.01). During follow-up, 267 (9.7%) patients with IA/SO AB RX had a UTI-related emergency department (ED) visit versus 202 (6.5%) patients with AP&OP AB RX (p &lt; 0.001). Mean UTI-related HRU costs were significantly higher for IA/SO (&5048) versus AP&OP AB RX (&3633; p = 0.01). After adjusting for patient characteristics, patients with IA/SO AB RX were 40% more likely than those with AP&OP AB RX to have a UTI-related ED visit (odds ratio 1.40; 95% confidence interval 1.15–1.71) during follow-up (Table 3). Adjusted HRU costs for IA/SO AB RX (vs AP&OP) were numerically higher for index uUTI episode (by &1772), and UTI-related (by &1102) and all-cause (by &1528) charges during follow-up (Figure). Table 2. Baseline characteristics of patients stratified by appropriateness of AB RX Table 3. Associations of AP&OP AB RX and HRU charges for index episode and 12-month follow-up Figure. Total 12-month UTI-related and all-cause visit charges (adjusted), stratified by appropriateness of AB RX at index and during follow-up Conclusion IA/SO AB RX was associated with higher overall and UTI-related HRU and costs during index episode and 12-month follow-up, highlighting a need for education on applying prescription guidelines and the use of culture-based RX. Disclosures Rena Moon, MD, Premier Applied Sciences, Premier Inc. (Employee) Alen Marijam, MSc, GlaxoSmithKline plc. (Employee, Shareholder) Fanny S. Mitrani-Gold, MPH, GlaxoSmithKline plc. (Employee, Shareholder) Daniel C. Gibbons, PhD, GlaxoSmithKline plc. (Employee, Shareholder) Alex Kartashov, PhD, Premier Applied Sciences, Premier Inc. (Employee) Ning Rosenthal, MD, Premier Applied Sciences, Premier Inc. (Employee, Shareholder) Ashish V. Joshi, PhD, GlaxoSmithKline plc. (Employee, Shareholder)