Development of Predictive Models to Inform a Novel Risk Categorization Framework for Antibiotic Resistance in E. coli-Causing Uncomplicated Urinary Tract Infection.

BACKGROUND: In clinical practice, challenges in identifying patients with uncomplicated urinary tract infections (uUTIs) at risk of antibiotic non-susceptibility may lead to inappropriate prescribing and contribute to antibiotic resistance. We developed predictive models to quantify risk of non-susceptibility to four commonly prescribed antibiotic classes for uUTI, identify predictors of non-susceptibility to each class, and construct a corresponding risk categorization framework for non-susceptibility. METHODS: Eligible females aged ≥12 years with E. coli-caused uUTI were identified from Optum's de-identified Electronic Health Record dataset (10/1/2015‒2/29/2020). Four predictive models were developed to predict non-susceptibility to each antibiotic class and a risk categorization framework was developed to classify patients' isolates as low, moderate, and high risk of non-susceptibility to each antibiotic class. RESULTS: Predictive models were developed among 87487 patients. Key predictors of having a non-susceptible isolate to ≥3 antibiotic classes included number of previous UTI episodes, prior ß-lactam non-susceptibility, prior fluoroquinolone treatment, census bureau region, and race. The risk categorization framework classified 8.1%, 14.4%, 17.4%, and 6.3% of patients as having isolates at high risk of non-susceptibility to nitrofurantoin, trimethoprim-sulfamethoxazole, ß-lactams, and fluoroquinolones, respectively. Across classes, the proportion of patients categorized as having high-risk isolates was 3-12 folds higher among patients with non-susceptible isolates versus susceptible isolates. CONCLUSIONS: Our predictive models highlight factors that increase risk of non-susceptibility to antibiotics for uUTIs, while the risk categorization framework contextualizes risk of non-susceptibility to these treatments. Our findings provide valuable insight to clinicians treating uUTIs and may help inform empiric prescribing in this population.

Likelihood of Antimicrobial Resistance in Urinary E coli Isolates among US Female Patients with Recurrent vs Non-Recurrent Uncomplicated Urinary Tract Infection.

OBJECTIVE: To assess the relative likelihood of antimicrobial resistance (AMR) and multi-drug resistance (MDR) among E coli isolates from outpatients with recurrent versus non-recurrent uncomplicated urinary tract infection (uUTI). METHODS: In this retrospective observational US cohort study, female outpatients (≥12 years) with uUTI, positive E coli culture, and treated with ≥1 oral antibiotic within ±5 days of diagnosis were grouped into recurrent and non-recurrent uUTI cohorts per their UTI history (past 12 months). AMR to specific drug classes was evaluated at index. Univariable and multivariable logistic regression models estimated the likelihood of not-susceptible E coli isolates (AMR/MDR) among patients with recurrent uUTI versus non-recurrent uUTI. RESULTS: Recurrent (N = 12,234) and non-recurrent (N = 68,033) uUTI cohorts had similar distributions (race, ethnicity, region). Patients with recurrent uUTI had a higher prevalence of E coli resistance to trimethoprim-sulfamethoxazole (21.8% vs 18.7%) and fluoroquinolones (14.2% vs 8.6%), and more isolates were extended-spectrum ß-lactamase-producing (5.9% vs 4.1%) compared to non-recurrent uUTI patients. Patients with recurrent uUTI had a higher likelihood (odds ratio [95% confidence interval]) of any AMR (1.28 [1.22-1.34]), single drug-class resistance (1.18 [1.12-1.24]), and resistance to 2 (1.53 [1.41-1.67]) or ≥3 drug classes (1.70 [1.48-1.96]) (all P <.001). CONCLUSION: This study delineated the likelihood of AMR and MDR among E coli isolates from patients with recurrent versus non-recurrent uUTI. While some treatment guidelines support empiric therapy in recurrent uUTI, the increased likelihood of resistance among these patients suggests that culture and susceptibility testing should be undertaken to inform recurrent uUTI treatment.

Prevalence, regional distribution, and trends of antimicrobial resistance among female outpatients with urine Klebsiella spp. isolates: a multicenter evaluation in the United States between 2011 and 2019.

BACKGROUND: Antimicrobial resistance research in uncomplicated urinary tract infection typically focuses on the main causative pathogen, Escherichia coli; however, little is known about the antimicrobial resistance burden of Klebsiella species, which can also cause uncomplicated urinary tract infections. This retrospective cohort study assessed the prevalence and geographic distribution of antimicrobial resistance among Klebsiella species and antimicrobial resistance trends for K. pneumoniae in the United States (2011-2019). METHODS: K. pneumoniae and K. oxytoca urine isolates (30-day, non-duplicate) among female outpatients (aged ≥ 12 years) with presumed uUTI at 304 centers in the United States were classified by resistance phenotype(s): not susceptible to nitrofurantoin, trimethoprim/sulfamethoxazole, or fluoroquinolone, extended-spectrum ß-lactamase-positive/not susceptible; and multidrug-resistant based on ≥ 2 and ≥ 3 resistance phenotypes. Antimicrobial resistance prevalence by census division and age, as well as antimicrobial resistance trends over time for Klebsiella species, were assessed using generalized estimating equations. RESULTS: 270,552 Klebsiella species isolates were evaluated (250,719 K. pneumoniae; 19,833 K. oxytoca). The most frequent resistance phenotypes in 2019 were nitrofurantoin not susceptible (Klebsiella species: 54.0%; K. pneumoniae: 57.3%; K. oxytoca: 15.1%) and trimethoprim/sulfamethoxazole not susceptible (Klebsiella species: 10.4%; K. pneumoniae: 10.6%; K. oxytoca: 8.6%). Extended-spectrum ß-lactamase-positive/not susceptible prevalence was 5.4%, 5.3%, and 6.8%, respectively. K. pneumoniae resistance phenotype prevalence varied (p < 0.0001) geographically and by age, and increased over time (except for the nitrofurantoin not susceptible phenotype, which was stable and > 50% throughout). CONCLUSIONS: There is a high antimicrobial resistance prevalence and increasing antimicrobial resistance trends among K. pneumoniae isolates from female outpatients in the United States with presumed uncomplicated urinary tract infection. Awareness of K. pneumoniae antimicrobial resistance helps to optimize empiric uncomplicated urinary tract infection treatment.

Escherichia coli resistance, treatment patterns and clinical outcomes among females with uUTI in Germany: a retrospective physician-based chart review study.

Real-world data were collected to examine antimicrobial resistance (AMR) prevalence, treatment patterns, and clinical outcomes among female patients with uncomplicated urinary tract infection (uUTI) in Germany. Data were from a retrospective physician-based chart review completed by physicians treating patients with uUTI. Non-pregnant women aged ≥ 12 years, with a uUTI diagnosis, an E. coli-positive urine culture between January 2017-December 2019, and susceptibility test results for ≥ 4 drug classes were eligible. Patients were stratified into three cohorts by drug class susceptibility: susceptible to all (SUS), resistant to one or two drug classes (DR1/2), and resistant to ≥ 3 (MDR) drug classes tested. Among 386 eligible patients [SUS (67.1%); DR1/2 (29.0%); MDR (3.9%)], AMR prevalence was highest for FMIs (18.3%) and lowest for fluoroquinolones (5.2%). The most prescribed drugs were fosfomycin in SUS (44.0%), DR1/2 (41.4%), and fluoroquinolones in MDR (40.0%). Treatment for uUTI failed for 8.8% of patients; failure was more likely in MDR versus SUS [adjusted odds ratio [95% CI] = 4.21 [1.14-1.50]; P = 0.031); incidence of recurrent infection in the 6-months post-index period was higher in DR1/2 versus SUS. These findings may have implications for empiric prescribing, suggesting an unmet need for new treatments.

Unmet needs in uncomplicated urinary tract infection in the United States and Germany: a physician survey.

BACKGROUND: Uncomplicated urinary tract infections (uUTIs/acute cystitis) are among the most common infections in women worldwide. There are differences in uUTI treatment guidelines between countries and understanding the needs of physicians in diverse healthcare systems is important for developing new treatments. We performed a survey of physicians in the United States (US) and Germany to understand their perceptions of, and management approaches to uUTI. METHODS: This was a cross-sectional online survey of physicians in the US and Germany who were actively treating patients with uUTI (≥ 10 patients/month). Physicians were recruited via a specialist panel and the survey was piloted with 2 physicians (1 US, 1 Germany) prior to study commencement. Data were analyzed with descriptive statistics. RESULTS: A total of 300 physicians were surveyed (n = 200 US, n = 100 Germany). Across countries and specialties, physicians estimated 16-43% of patients did not receive complete relief from initial therapy and 33-37% had recurrent infections. Urine culture and susceptibility testing was more common in the US and among urologists. The most commonly selected first-line therapy was trimethoprim-sulfamethoxazole in the US (76%) and fosfomycin in Germany (61%). Ciprofloxacin was the most selected following multiple treatment failures (51% US, 45% Germany). Overall, 35% of US and 45% of German physicians agreed with the statement "I feel there is a good selection of treatment options" and ≥ 50% felt that current treatments provided good symptom relief. More than 90% of physicians included symptom relief amongst their top 3 treatment goals. The overall impact of symptoms on patients' lives was rated "a great deal" by 51% of US and 38% of German physicians, increasing with each treatment failure. Most physicians (> 80%) agreed that antimicrobial resistance (AMR) is serious, but fewer (56% US, 46% Germany) had a high level of confidence in their knowledge of AMR. CONCLUSIONS: Treatment goals for uUTI were similar in the US and Germany, although with nuances to disease management approaches. Physicians recognized that treatment failures have a significant impact on patients' lives and that AMR is a serious problem, though many did not have confidence in their own knowledge of AMR.

Older patient age and prior antimicrobial use strongly predict antimicrobial resistance in Escherichia coli isolates recovered from urinary tract infections among female outpatients.

BACKGROUND: Increasing prevalence of antimicrobial resistance (AMR), including multidrug resistance (MDR), among Escherichia coli (E. coli) makes treatment of uncomplicated urinary tract infection (uUTI) difficult. We assessed risk factors for fluoroquinolone (FQ)-not-susceptible (NS) and MDR E. coli among US female outpatients. METHODS: This retrospective cohort study utilized data from female outpatients aged ≥ 12 years with E. coli positive urine culture and oral antimicrobial prescription ± 1 day from index. We assessed patient-level factors within 90 and 91-360 days prior to index as predictors of FQ NS (intermediate/resistant) and MDR (NS to ≥ 1 drug across ≥ 3 classes) E. coli: age, prior oral antimicrobial dispensing, prior AMR phenotypes, prior urine culture, and prior hospitalization. RESULTS: Among 1,858 outpatients with urine-isolated E. coli, 369 (19.9%) had FQ NS and 59 (3.2%) had MDR isolates. After multivariable adjustment, independent risk factors (p < 0.03) for FQ NS E. coli were older age, prior FQ NS isolates, prior dispensing of FQ, and dispensing of any oral antibiotic. Independent risk factors (p < 0.02) for MDR were prior extended-spectrum ß-lactamase-producing isolates (ESBL+), prior FQ dispensing, and prior oral antibiotic dispensing. CONCLUSIONS: In women with uUTI due to E. coli, prior dispensing of FQ or any oral antibiotic within 90 days predicted FQ NS and MDR urine E. coli. Prior urine culture with FQ NS isolates and older age were predictive of FQ NS E. coli. Prior ESBL+ was predictive of MDR E. coli. These data could help identify patients at risk for AMR E. coli and inform empiric prescribing.

Activity impairment, health-related quality of life, productivity, and self-reported resource use and associated costs of uncomplicated urinary tract infection among women in the United States.

BACKGROUND: Uncomplicated urinary tract infections (uUTIs) are among the most common infections in the US. Only a few studies, however, describe the impact of uUTIs from the patient perspective. METHODS: A cross-sectional online survey of US women aged ≥18 years was performed assessing uUTI burden regarding activity impairment, health-related quality of life (HRQoL), workplace productivity, healthcare resource use (HRU), and costs. Participants who self-reported a uUTI in the prior 60 days treated with ≥1 oral antibiotic were included. Activity impairment was assessed with the Activity Impairment Assessment scale. HRQoL was assessed using a modified Short Form 36 (SF-36). Direct costs were sum of out-of-pocket expenditures and monetized HRU; indirect costs were calculated using Work Productivity and Activity Impairment (WPAI). Participants were stratified by uUTI recurrence, number of prescribed antibiotics for recent uUTI and therapy appropriateness (1 first-line/1 second-line/multiple antibiotics). Multivariable regression analysis assessed the relationship between stratifications and outcomes while controlling for demographic/clinical characteristics. Propensity score matching was used to compare participants to a matched population from the 2020 National Health and Wellness Survey (NHWS), to control for any impact of COVID-19 on responses. RESULTS: Among 375 participants, impaired activities included sexual intercourse (66.9%), sleep (60.8%) and exercise (52.3%). HRQoL was worse (p<0.0001) than the NHWS population (46.4 vs. 51.3 [physical component score]; 40.0 vs. 46.9 [mental component score]; 0.63 vs. 0.72 [health utility index]). All included WPAI assessments were worse for uUTI cohort vs. NHWS (p<0.0001). Adjusted direct costs were higher for participants receiving 2 vs. 1 antibiotic ($2090 vs. $776; p<0.0001) and receiving multiple antibiotics vs. 1 first-line ($1642 vs. $875; p = 0.002). Recurrent uUTI was associated with increased activity impairment, worse HRQoL, and costs vs. non-recurrent. CONCLUSIONS: uUTIs were associated with increased activity impairment, worse productivity, and reduced HRQoL. Higher costs were found vs. a matched population.

A systematic scoping review of faropenem and other oral penems: treatment of Enterobacterales infections, development of resistance and cross-resistance to carbapenems.

Background: Antimicrobial resistance is an urgent global healthcare concern. Beyond carbapenems as broad-spectrum, often 'last resort' antibiotics, oral penem antibiotics currently are approved only in Japan and India, used for the treatment of indications including urinary tract infections (UTIs). Exploring oral penem use to better understand the impact of antibiotic resistance on public health would help inform the management of infectious diseases, including UTIs. Scoping Review Methodology: This scoping review investigated the impact of faropenem and other oral penems on Enterobacterales infection treatment and evaluated evidence for faropenem resistance and cross-resistance to carbapenems. PubMed, Embase, J-STAGE and CiNii were searched for relevant English- or Japanese-language articles published between 1 January 1996 and 6 August 2021. Key Findings: From 705 unique publications, 29 eligible articles were included (16 in vitro studies; 10 clinical trials; 2 in vitro and in vivo studies; and 1 retrospective medical chart review). Limited evidence described faropenem to treat infectious disease; only four randomized clinical trials were identified. Faropenem dosing regimens varied broadly within and between indications. One study indicated potential dependence of penem efficacy on underlying antibiotic resistance mechanisms, while several studies reported UTI persistence or recurrence after faropenem treatment. In vitro MIC data suggested some potential bacterial resistance to faropenem, while limited clinical data showed resistance emergence after faropenem treatment. Preliminary in vitro evidence suggested faropenem resistance might foster cross-resistance to carbapenems. Overall, very limited clinical evidence describes faropenem for treating infectious diseases. Preclinical and clinical research investment and dedicated community surveillance monitoring is crucial for understanding faropenem treatment patterns, resistance and potential cross-resistance to carbapenems.

Impact of suboptimal or inappropriate treatment on healthcare resource use and cost among patients with uncomplicated urinary tract infection: an analysis of integrated delivery network electronic health records.

BACKGROUND: Although uncomplicated urinary tract infections (uUTIs; occurring in female patients without urological abnormalities or history of urological procedures or complicating comorbidities) are one of the most common community infections in the United States (US), limited data are available concerning associations between antibiotic resistance, suboptimal prescribing, and the economic burden of uUTI. We examined the prevalence of suboptimal antibiotic prescribing and antibiotic resistance and its effects on healthcare resource use and costs. METHODS: This retrospective cohort study utilized electronic health record data from a large Mid-Atlantic US integrated delivery network database, collected July 2016-March 2020. Female patients aged ≥ 12 years with a uUTI, who received ≥ 1 oral antibiotic treatment within ± 5 days of index uUTI diagnosis, and had ≥ 1 urine culture with antimicrobial susceptibility test, were eligible for inclusion in the study. The study examined the proportion of antibiotics that were inappropriately or suboptimally prescribed among patients with confirmed uUTI, and total healthcare costs (all-cause and UTI-related) within 6 months after a uUTI, stratified by antibiotic susceptibility and/or inappropriate or suboptimal treatment. Patient outcomes were assessed after 1:1 propensity score matching of patients with antibiotic-susceptible versus not-susceptible isolates and then by other covariates (e.g., demographics and recent healthcare use). A similar propensity score calculation was used to analyze the effect of inappropriate/suboptimal treatment on health outcomes. Costs were adjusted to 2020 US dollars ($). RESULTS: Among 2565 patients with a uUTI included in the analysis, the most commonly prescribed antibiotics were nitrofurantoin (61%), trimethoprim-sulfamethoxazole (19%), and ciprofloxacin (15%). More than one-third of the sample (40.2%) had isolates that were not-susceptible to ≥ 1 antibiotic indicated for treating patients with uUTI. Two-thirds (66.6%) of study-eligible patients were prescribed appropriate treatment; 29.9% and 11.9% were prescribed suboptimal and/or inappropriate treatment, respectively. Inappropriate or suboptimally prescribed patients had greater all-cause and UTI-related costs compared with appropriately prescribed patients. Differences were most striking among patients with antibiotic not-susceptible isolates. CONCLUSIONS: These findings highlight how the increasing prevalence of antibiotic resistance combined with suboptimal treatment of patients with uUTI increases the burden on healthcare systems. The finding underlines the need for improved prescribing accuracy by better understanding regional resistance rates and developing improved diagnostic tests.

Treatment patterns, healthcare resource use, and costs associated with uncomplicated urinary tract infection among female patients in the United States.

BACKGROUND: We evaluated associations between antibiotic prescription and healthcare resource use and costs (Part A), and between antibiotic switching and healthcare resource use, costs, and uncomplicated urinary tract infection recurrence (Part B) in female patients with uncomplicated urinary tract infection in the United States. METHODS: This retrospective cohort study of linked Optum and Premier Healthcare Database data included female patients ≥12 years old with an uncomplicated urinary tract infection diagnosis (index date), who were prescribed antibiotics during an outpatient/emergency department visit between January 1, 2013 and December 31, 2018. In Part A, patients were stratified by antibiotic prescription appropriateness: appropriate and optimal (compliant with Infectious Diseases Society of America 2011 guidelines for drug class/treatment duration) versus inappropriate/suboptimal (inappropriate drug class/treatment duration per Infectious Diseases Society of America 2011 guidelines, and/or treatment failure). In Part B, patients were stratified by treatment pattern (antibiotic switch vs no antibiotic switch). Healthcare resource use and costs during index episode (within 28 days of index date) and 12-month follow-up were compared. RESULTS: Of 5870 patients (mean age 44.5 years), 2762 (47.1%) had inappropriate/suboptimal prescriptions and 567 (9.7%) switched antibiotic. Inappropriate/suboptimal prescriptions were associated with higher healthcare resource use (mean number of ambulatory care and pharmacy claims [both p < 0.001]), and higher total mean cost (inpatient, outpatient/emergency department, ambulatory visits, and pharmacy costs) per patient ($2616) than appropriate and optimal prescriptions ($649; p < 0.001) (Part A). Antibiotic switching was associated with more pharmacy claims and higher total mean costs (p ≤ 0.01), and a higher incidence of recurrent uncomplicated urinary tract infection (18.9%) than no antibiotic switching (14.2%; p < 0.001) (Part B). CONCLUSIONS: Inappropriate/suboptimal prescriptions and antibiotic switching were associated with high costs, ambulatory care, and pharmacy claims, suggesting a need for improved uncomplicated urinary tract infection prescribing practices in the United States.

Systematic Review and Meta-Analysis to Estimate the Treatment Effect and Inform a Noninferiority Margin for a Phase 3 Noninferiority Trial in Uncomplicated Urogenital Gonorrhea.

BACKGROUND: Active-controlled noninferiority studies are used to investigate novel agents for uncomplicated urogenital gonorrhea (uUGC) as placebo-controlled trials are unethical. A systematic literature review and meta-analysis were conducted to estimate the ceftriaxone and proxy-for-placebo microbiological treatment effect and determine an appropriate noninferiority margin for phase 3 trials. METHODS: Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines were followed. To account for interstudy variability, a weighted, noniterative random-effects model was fitted using "R" software to estimate the microbiological response rate and 95% confidence intervals (CIs) for ceftriaxone and proxy-for-placebo (treatment with an antibiotic the isolate was subsequently confirmed resistant to, or spontaneous resolution without treatment). I2 , τ2 , and P values were computed and included in the meta-analysis forest plot. RESULTS: Seventeen studies were included in the meta-analysis; 14 reported ceftriaxone response in micro-intent-to-treat and microbiologically evaluable populations, and 3 reported proxy-for-placebo treatment response in uUGC (microbiologically evaluable population only). Microbiological treatment effect was estimated by subtracting the upper end of the CI for placebo from the lower end of the CI for ceftriaxone. Overall microbiological response was 98% (95% CI, 97-99) for ceftriaxone and 44% (95% CI, 34-54) for proxy-for-placebo, resulting in a microbiological treatment effect of 43%. A noninferiority margin of 15% preserved 65% of the ceftriaxone treatment effect, exceeding the 50% recommended per US Food and Drug Administration guidance for noninferiority studies. CONCLUSIONS: Results of this systematic literature review and meta-analysis could help inform the design, conduct, and analysis of future clinical studies in uUGC.

Economic burden of antibiotic-not-susceptible isolates in uncomplicated urinary tract infection: Analysis of a US integrated delivery network database.

BACKGROUND: Uncomplicated urinary tract infections (uUTIs) are one of the most common bacterial infections in the United States (US). Contemporary data are important for understanding the health economic impact of antimicrobial-resistant uUTIs. We compared the economic burden among patients with uUTI isolates susceptible or not-susceptible to the initial antibiotic prescription. METHODS: This retrospective cohort study utilized electronic health record data (1 July 2016-31 March 2020) from a large Mid-Atlantic US integrated delivery network database. Patients were females aged ≥ 12 years with a uUTI, who received oral antibiotic treatment and had ≥ 1 urine culture within ± 5 days of diagnosis. The primary outcome was the difference in healthcare resource use and costs (all-cause, urinary tract infection [UTI]-related) among patients with susceptible versus not-susceptible isolates during the 6 months after the index uUTI diagnosis. Secondary outcomes included: pharmacy costs, hospital admissions and emergency department visits, as well as the probability of uUTI progressing to complicated UTI (cUTI) between patients with susceptible and not-susceptible isolates. Patient outcomes were compared using 1:1 propensity score matching. Winsorized costs were adjusted to 2020 quarter 1 US dollars ($). RESULTS: A total of 2565 patients were eligible for analysis. The propensity score-matched sample comprised 2018 patients, with an average age of 44.0 and 41.0 years for the susceptible and not-susceptible populations, respectively. In the 6 months post-index uUTI event, patients with not-susceptible isolates had significantly more all-cause prescriptions orders (+ 1.41 [P = 0.001]), UTI-related prescriptions orders (+ 0.26 [P < 0.001]) and a higher probability of all-cause inpatient (+ 1.4% [P = 0.009]), outpatient (+ 6.1% [P = 0.006]), or UTI-related outpatient (+ 3.7% [P = 0.039]) encounters. Patients with a uUTI and an antibiotic-not-susceptible isolate were significantly more likely to progress to cUTI than those with susceptible isolates (odds ratio: 2.35 [confidence interval: 1.66-3.33; P < 0.001]). Over 6 months, patients with not-susceptible versus susceptible isolates had significantly higher all-cause costs (+ $426 [P = 0.031]) and UTI-related costs (+ $157 [P = 0.034]). CONCLUSIONS: Patients with a uUTI caused by antibiotic-not-susceptible isolates had higher healthcare resource usage, costs, and increased likelihood of progressing to cUTI than those with antibiotic-susceptible isolates.

Risk Factors Associated With Antimicrobial Resistance and Adverse Short-Term Health Outcomes Among Adult and Adolescent Female Outpatients With Uncomplicated Urinary Tract Infection.

Background: Increasing antimicrobial resistance makes treating uncomplicated urinary tract infections (uUTIs) difficult. We compared whether adverse short-term outcomes among US female patients were more common when initial antimicrobial therapy did not cover the causative uropathogen. Methods: This retrospective cohort study used data from female outpatients aged ≥12 years, with a positive urine culture and dispensing of an oral antibiotic ±1 day from index culture. Isolate susceptibility to the antimicrobial initially dispensed, patient age, and history of antimicrobial exposure, resistance, and all-cause hospitalization within 12 months of index culture were evaluated for associations with adverse outcomes during 28-day follow up. Outcomes assessed were new antimicrobial dispensing, all-cause hospitalization, and all-cause outpatient emergency department/clinic visits. Results: Of 2366 uUTIs, 1908 (80.6%) were caused by isolates susceptible and 458 (19.4%) by isolates not susceptible (intermediate/resistant) to initial antimicrobial treatment. Within 28 days, patients with episodes caused by not susceptible isolates were 60% more likely to receive a new antimicrobial versus episodes with susceptible isolates (29.0% vs 18.1%; 95% confidence interval, 1.3-2.1; P < .0001). Other variables associated with new antibiotic dispenses within 28 days were older age, prior antimicrobial exposure, or prior nitrofurantoin-not-susceptible uropathogens (P < .05). Older age, prior antimicrobial-resistant urine isolates, and prior hospitalization were associated with all-cause hospitalization (P < .05). Prior fluoroquinolone-not-susceptible isolates or oral antibiotic dispensing within 12 months of index culture were associated with subsequent all-cause outpatient visits (P < .05). Conclusions: New antimicrobial dispensing within the 28-day follow-up period was associated with uUTIs where the uropathogen was not susceptible to initial antimicrobial treatment. Older age and prior antimicrobial exposure, resistance, and hospitalization also identified patients at risk of adverse outcomes.

Antimicrobial Resistance Trends in Urine Escherichia coli Isolates From Adult and Adolescent Females in the United States From 2011 to 2019: Rising ESBL Strains and Impact on Patient Management.

BACKGROUND: Uncomplicated urinary tract infection (uUTI) is predominantly caused by Escherichia coli, which has increasing antimicrobial resistance (AMR) at the United States (US)-community level. As uUTI is often treated empirically, assessing AMR is challenging, and there are limited contemporary data characterizing period prevalence in the US. METHODS: This was a retrospective study of AMR using Becton, Dickinson and Company Insights Research Database (Franklin Lakes, New Jersey, US) data collected 2011-2019. Thirty-day, nonduplicate Escherichia coli urine isolates from US female outpatients (aged ≥12 years) were included. Isolates were evaluated for nonsusceptibility (intermediate/resistant) to trimethoprim-sulfamethoxazole, fluoroquinolones, or nitrofurantoin, and assessed for extended-spectrum ß-lactamase production (ESBL+) and for ≥2 or ≥3 drug-resistance phenotypes. Generalized estimating equations were used to model AMR trends over time and by US census region. RESULTS: Among 1 513 882 E. coli isolates, the overall prevalence of isolates nonsusceptible to trimethoprim-sulfamethoxazole, fluoroquinolones, and nitrofurantoin was 25.4%, 21.1%, and 3.8%, respectively. Among the isolates, 6.4% were ESBL+, 14.4% had ≥2 drug-resistance phenotypes, and 3.8% had ≥3. Modeling demonstrated a relative average yearly increase of 7.7% (95% confidence interval [CI], 7.2-8.2%) for ESBL+ isolates and 2.7% (95% CI, 2.2-3.2%) for ≥3 drug-phenotypes (both P < .0001). Modeling also demonstrated significant variation in AMR prevalence between US census regions (P < .001). CONCLUSIONS: Period prevalence of AMR among US outpatient urine-isolated E. coli was high, and for multidrug-resistance phenotypes increased during the study period with significant variation between census regions. Knowledge of regional AMR rates helps inform empiric treatment of community-onset uUTI and highlights the AMR burden to physicians.

Using rapid point-of-care tests to inform antibiotic choice to mitigate drug resistance in gonorrhoea.

BackgroundThe first cases of extensively drug resistant gonorrhoea were recorded in the United Kingdom in 2018. There is a public health need for strategies on how to deploy existing and novel antibiotics to minimise the risk of resistance development. As rapid point-of-care tests (POCTs) to predict susceptibility are coming to clinical use, coupling the introduction of an antibiotic with diagnostics that can slow resistance emergence may offer a novel paradigm for maximising antibiotic benefits. Gepotidacin is a novel antibiotic with known resistance and resistance-predisposing mutations. In particular, a mutation that confers resistance to ciprofloxacin acts as the 'stepping-stone' mutation to gepotidacin resistance.AimTo investigate how POCTs detecting Neisseria gonorrhoeae resistance mutations for ciprofloxacin and gepotidacin can be used to minimise the risk of resistance development to gepotidacin.MethodsWe use individual-based stochastic simulations to formally investigate the aim.ResultsThe level of testing needed to reduce the risk of resistance development depends on the mutation rate under treatment and the prevalence of stepping-stone mutations. A POCT is most effective if the mutation rate under antibiotic treatment is no more than two orders of magnitude above the mutation rate without treatment and the prevalence of stepping-stone mutations is 1-13%.ConclusionMutation frequencies and rates should be considered when estimating the POCT usage required to reduce the risk of resistance development in a given population. Molecular POCTs for resistance mutations and stepping-stone mutations to resistance are likely to become important tools in antibiotic stewardship.

Systematic review and meta-analysis to estimate the antibacterial treatment effect of nitrofurantoin for a non-inferiority trial in uncomplicated urinary tract infection.

OBJECTIVES: Active-comparator, non-inferiority study designs are used in uncomplicated urinary tract infection (uUTI) to establish the efficacy of a new antibacterial, given the availability of effective antibiotics. Here we estimated the treatment effect of a planned antimicrobial comparator (nitrofurantoin) from historical trial data to properly design an upcoming non-inferiority trial in uUTI. METHODS: A systematic literature review and meta-analysis was conducted in compliance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, which incorporate recommendations for standardised data quality assessment, reporting of results, risk of bias assessment and sensitivity analyses. To account for interstudy variability, a weighted, non-iterative, random-effects model was fit using R software to obtain estimates of the microbiological response rate and corresponding 95% confidence interval (CI) for nitrofurantoin and placebo treatment. Interstudy heterogeneity was assessed with Cochran's χ2 test for interstudy heterogeneity; I2 statistic and P-values were computed and included in the forest plot of the meta-analysis. RESULTS: Twelve unique studies met the final eligibility criteria for meta-analysis inclusion; three trials assessed placebo efficacy, eight trials assessed nitrofurantoin efficacy, and one study assessed both nitrofurantoin and placebo efficacy in uUTI. The overall microbiological response (95% CI) was 0.766 (0.665-0.867) for nitrofurantoin and 0.342 (0.288-0.397) for placebo. CONCLUSION: The corresponding treatment effect estimate for nitrofurantoin was 26.8%, which supports a conservative non-inferiority margin of 12.5% and is consistent with the recently published draft FDA guidance. The findings from this systematic review and meta-analysis may inform future antibacterial trials by providing non-inferiority margin justification.

Systematic Review and Meta-Analysis To Estimate Antibacterial Treatment Effect in Acute Bacterial Skin and Skin Structure Infection.

A systematic literature review and meta-analysis were conducted to estimate the antibacterial treatment effect for linezolid and ceftaroline to inform on the design of acute bacterial skin and skin structure infection (ABSSSI) noninferiority trials. The primary endpoints included an early clinical treatment response (ECTR) defined as cessation of lesion spread at 48 to 72 h postrandomization and the test-of-cure (TOC) response defined as total resolution of the infection at 7 to 14 days posttreatment. The systematic review identified no placebo-controlled trials in ABSSSI, 4 placebo-controlled trials in uncomplicated skin and soft tissue infection as a proxy for placebo in ABSSSI, 12 linezolid trials in ABSSSI, 3 ceftaroline trials in ABSSSI, and 2 trials for nonantibacterial treatment. The ECTR rates at 48 to 72 h and corresponding 95% confidence intervals (CI) were 78.7% (95% CI, 61.1 to 96.3%) for linezolid, 74.0% (95% CI, 69.7 to 78.3%) for ceftaroline, and 59.0% (95% CI, 52.8 to 65.3%) for nonantibacterial treatment. The early clinical treatment effect could not be estimated, given no available placebo or proxy for placebo data for this endpoint. Clinical, methodological, and statistical heterogeneity influenced the selection of trials for the meta-analysis of the TOC treatment effect estimation. The pooled estimates of the TOC treatment response were 31.0% (95% CI, 6.2 to 55.9%) for the proxy for placebo, 88.1% (95% CI, 81.0 to 95.1%) for linezolid, and 86.1% (95% CI, 83.7 to 88.6%) for ceftaroline. The TOC clinical treatment effect estimation was 25.1% for linezolid and 27.8% for ceftaroline. The antibacterial treatment effect estimation at TOC will inform on the design and analysis of future noninferiority ABSSSI clinical trials.

Systematic review and meta-analysis of antimicrobial treatment effect estimation in complicated urinary tract infection.

Noninferiority trial design and analyses are commonly used to establish the effectiveness of a new antimicrobial drug for treatment of serious infections such as complicated urinary tract infection (cUTI). A systematic review and meta-analysis were conducted to estimate the treatment effects of three potential active comparator drugs for the design of a noninferiority trial. The systematic review identified no placebo trials of cUTI, four clinical trials of cUTI with uncomplicated urinary tract infection as a proxy for placebo, and nine trials with reports of treatment effect estimates for doripenem, levofloxacin, or imipenem-cilastatin. In the meta-analysis, the primary efficacy endpoint of interest was the microbiological eradication rate at the test-of-cure visit in the microbiological intent-to-treat population. The estimated eradication rates and corresponding 95% confidence intervals (CI) were 31.8% (26.5% to 37.2%) for placebo, 81% (77.7% to 84.2%) for doripenem, 79% (75.9% to 82.2%) for levofloxacin, and 80.5% (71.9% to 89.1%) for imipenem-cilastatin. The treatment effect estimates were 40.5% for doripenem, 38.7% for levofloxacin, 34.7% for imipenem-cilastatin, and 40.8% overall. These treatment effect estimates can be used to inform the design and analysis of future noninferiority trials in cUTI study populations.

The incidence of idiopathic thrombocytopenic purpura among adults: a population-based study and literature review.

Published data on the epidemiology of idiopathic thrombocytopenic purpura (ITP) among adults are very limited. We conducted a study of ITP incidence using the General Practice Research Database in the United Kingdom. From 1992 to 2005, there were 840 cases of ITP among adults considering 21 749 623 person-years (PYs) of follow-up, for a crude incidence of 3.9 per 100 000 PYs [95% confidence interval (CI): 3.6, 4.1]. The incidence was higher among women [4.5 per 100 000 PYs (95% CI: 4.2, 4.9)] than men [3.2 per 100 000 PYs (95% CI: 2.8, 3.5)]. Among both women and men, incidence was higher at older ages and in later study years. In a systematic review of previously published literature, incidence of ITP among adults ranged from 1.6 to 2.68 per 100 000 persons per year; prevalence ranged from 9.5 to 23.6 per 100 000 persons. In order to improve the understanding of the disease burden of ITP, future studies should include a clearly defined definition of ITP and focus on well-described source populations that are geographically and ethnically diverse.