Variability In Antibiotic Use Research Articles

1390. Assessing the Relationship between Community Social Vulnerability and Antibiotic Use in Nursing Homes

Abstract Background Health inequities impact healthcare delivery and outcomes, but the impacts of health inequities on antibiotic use and AR infections have been less frequently studied in nursing home residents. Nursing home residents are typically older, often have increased care needs requiring frequent contact with staff, and often have comorbidities or in-dwelling devices that make them vulnerable to infection. The community served by a nursing home may play a role in frequency and variability in antibiotic use, as health inequities may impact healthcare delivery and health status of patients, since both patients and caregivers are likely to be drawn from the surrounding community. We hypothesize that antibiotic use in nursing homes is impacted by the social vulnerability of the surrounding community. Methods We collected all reports of the proportion of residents who received antibiotics in the previous 7 days in 2019, which are reported monthly to the CMS Minimum Data Set. We assessed the proportion of facility residents using antibiotics by social vulnerability measures (from CDC Social Vulnerability Index) of the surrounding healthcare-seeking community (Hospital Service Areas from Dartmouth Health Atlas), using a hierarchical model to control for facility factors. Results We find considerable variability in antibiotic use across 14,908 US nursing homes (Figure 1A). After controlling for facility characteristics, facilities located in areas of greater community-level social vulnerability were associated with higher antibiotic use (Figure 1B). Figure 1. Antibiotic use in nursing homes and relationships with community social vulnerability. A) The distribution of the proportion of patients using antibiotics within the previous 7 days by facility. B) Coefficient estimates of a multilevel regression model. Controlling for facility-level factors (blue), community-level social vulnerability index appears to be related with more antibiotic use. Conclusion These findings indicate that community social vulnerability is associated with healthcare delivery within facilities. This association may result from differences in antibiotic prescribing behavior, infection prevention practices, or from disparity-driven differences in the health status of the resident population. This work is important for informing epidemiological models within healthcare facilities: failing to include heterogeneity of the surrounding community could bias transmission models and decrease the accuracy of targeted public health interventions to vulnerable facilities and communities. Disclosures All Authors: No reported disclosures.

Antibiotic Use in Lateral Skull Base Surgery: A Survey of the North American Skull Base Society.

Objectives Antibiotic use in lateral skull base surgery (LSBS) has not been thoroughly investigated in the literature. There is wide variability in antibiotic use and insufficient data to guide management. This study aims to describe the factors and patterns influencing antibiotic use in LSBS among the membership of the North American Skull Base Society (NASBS). Design An online-based survey was designed and distributed to the membership of the NASBS. Data was analyzed using bivariate analysis and logistic regression modeling. Setting Online-based questionnaire. Participants NASBS membership. Main Outcome Measures Use of intraoperative antibiotics and use of postoperative antibiotics. Results The survey response rate was 26% (208 respondents). Of the 208 total respondents, 143 (69%) respondents performed LSBS. Most respondents are neurosurgeons (69%) with the remaining being otolaryngologists (31%). The majority of respondents (79%) are fellowship-trained in skull base surgery. Academic or government physicians make up 69% of respondents and 31% are in private practice with or without academic affiliations. Bivariate analysis showed that practice setting significantly influenced intraoperative antibiotic use ( p = 0.01). Geographic location significantly affected postoperative antibiotic use ( p = 0.01). Postoperative antibiotic duration was significantly affected by presence of chronic otitis media, cerebrospinal fluid leak, and surgeon training ( p = 0.02, p = 0.01, and p = 0.006, respectively). Logistic regression modeling showed that the motivation to reduce infection significantly impacted postoperative antibiotic use ( p = 0.03). Conclusion This study demonstrates significant variations in intraoperative and postoperative antibiotic use in LSBS among the NASBS membership. Appropriate guidelines for optimal perioperative antibiotic use patterns should be determined with randomized studies in the future.

Description of antibiotic use variability among US nursing homes using electronic health record data.

Antibiotics are frequently prescribed in nursing homes; national data describing facility-level antibiotic use are lacking. The objective of this analysis was to describe variability in antibiotic use in nursing homes across the United States using electronic health record orders. A retrospective cohort study of antibiotic orders for 309,884 residents in 1,664 US nursing homes in 2016 were included in the analysis. Antibiotic use rates were calculated as antibiotic days of therapy (DOT) per 1,000 resident days and were compared by type of stay (short stay ≤100 days vs long stay >100 days). Prescribing indications and the duration of nursing home-initiated antibiotic orders were described. Facility-level correlations of antibiotic use, adjusting for resident health and facility characteristics, were assessed using multivariate linear regression models. In 2016, 54% of residents received at least 1 systemic antibiotic. The overall rate of antibiotic use was 88 DOT per 1,000 resident days. The 3 most common antibiotic classes prescribed were fluoroquinolones (18%), cephalosporins (18%), and urinary anti-infectives (9%). Antibiotics were most frequently prescribed for urinary tract infections, and the median duration of an antibiotic course was 7 days (interquartile range, 5-10). Higher facility antibiotic use rates correlated positively with higher proportions of short-stay residents, for-profit ownership, residents with low cognitive performance, and having at least 1 resident on a ventilator. Available facility-level characteristics only predicted a small proportion of variability observed (Model R2 version 0.24 software). Using electronic health record orders, variability was found among US nursing-home antibiotic prescribing practices, highlighting potential opportunities for targeted improvement of prescribing practices.

Factors favouring the evolution of multidrug resistance in bacteria

The evolution of multidrug antibiotic resistance in commensal bacteria is an important public health concern. Commensal bacteria such as Escherichia coli, Streptococcus pneumoniae or Staphylococcus aureus, are also opportunistic pathogens causing a large fraction of the community-acquired and hospital-acquired bacterial infections. Multidrug resistance (MDR) makes these infections harder to treat with antibiotics and may thus cause substantial additional morbidity and mortality. Here, we develop an evolutionary epidemiology model to identify the factors favouring the evolution of MDR in commensal bacteria. The model describes the evolution of antibiotic resistance in a commensal bacterial species evolving in a host population subjected to multiple antibiotic treatments. We combine statistical analysis of a large number of simulations and mathematical analysis to understand the model behaviour. We find that MDR evolves more readily when it is less costly than expected from the combinations of single resistances (positive epistasis). MDR frequently evolves when bacteria are in contact with multiple drugs prescribed in the host population, even if individual hosts are only treated with a single drug at a time. MDR is favoured when the host population is structured in different classes that vary in their rates of antibiotic treatment. However, under most circumstances, recombination between loci involved in resistance does not meaningfully affect the equilibrium frequency of MDR. Together, these results suggest that MDR is a frequent evolutionary outcome in commensal bacteria that encounter the variety of antibiotics prescribed in the host population. A better characterization of the variability in antibiotic use across the host population (e.g. across age classes or geographical location) would help predict which MDR genotypes will most readily evolve.

Considerable variability in antibiotic use among US children's hospitals in 2017-2018.

To characterize the prevalence of and seasonal and regional variation in inpatient antibiotic use among hospitalized US children in 2017-2018. We conducted a cross-sectional examination of hospitalized children. The assessments were conducted on a single day in spring (May 3, 2017), summer (August 2, 2017), fall (October 25, 2017), and winter (January 31, 2018). The main outcome of interest was receipt of an antibiotic on the study day. The study included 51 freestanding US children's hospitals that participate in the Pediatric Health Information System (PHIS). This study included all patients <18 years old who were admitted to a participating PHIS hospital, excluding patients who were admitted solely for research purposes. Of 52,769 total hospitalized children, 19,174 (36.3%) received antibiotics on the study day and 6,575 of these (12.5%) received broad-spectrum antibiotics. The overall prevalence of antibiotic use varied across hospitals from 22.3% to 51.9%. Antibiotic use prevalence was 29.2% among medical patients and 47.7% among surgical patients. Although there was no significant seasonal variation in antibiotic use prevalence, regional prevalence varied, ranging from 32.7% in the Midwest to 40.2% in the West (P < .001). Among units, pediatric intensive care unit patients had the highest prevalence of both overall and broad-spectrum antibiotic use at 58.3% and 26.6%, respectively (P < .001). On any given day in a national network of children's hospitals, more than one-third of hospitalized children received an antibiotic, and 1 in 8 received a broad-spectrum antibiotic. Variation across hospitals, setting and regions identifies potential opportunities for enhanced antibiotic stewardship activities.

Antibiotic Use in the Neonatal Intensive Care Unit Correlates Poorly with Sepsis Incidence

Previous studies in a group of neonatal intensive care units (NICUs) in California highlight wide variability in antibiotic use (NEJM JW Pediatr

1137. Variability of Antibiotic Use in Neonatal Intensive Care Units in the United States

BackgroundAlthough antibiotics are often indicated to treat early-life infections, such exposure may lead to serious adverse outcomes. Few studies have characterized patterns of antibiotic use among neonatal intensive care units (NICUs).MethodsWe performed a cross-sectional study of antibiotic use in 51 NICUs participating in the Pediatric Health Information System (PHIS), a database that includes clinical and resource utilization data for standalone children’s hospitals in the United States. Assessments were conducted on a single mid-week day of 2017. We examined the use of any antibiotic and broad-spectrum antibiotics using charge data in children admitted in each NICU on the study day. We compared antibiotic use among NICUs and geographical regions, and assessed its association with the NICU median case mix index (CMI) (as a surrogate for clinical complexity).Results2813 infants were hospitalized in NICUs on the study day; the median number of patients at each study site was 47 (IQR = 34 – 62). 90% were <1 month old, 56% were male, 46% were white, and 62% were extremely/very preterm. Overall, 23% received at least one antibiotic and 6% received broad-spectrum antibiotics. Broad-spectrum antibiotic use was twice as prevalent in surgical compared with medical patients. Antibiotic use prevalence varied by region, ranging from 19% in the Midwest to 26% in the West (table). Ampicillin, gentamicin and vancomycin were the most common antibiotics used (25.2%, 18.8% and 9.9%, respectively). Antibiotic use prevalence varied substantially across NICUs (Figure 1). There was a moderate but significant positive correlation between overall or broad-spectrum antibiotic use and median NICU CMI (Figure 2).ConclusionThere is substantial variability in antibiotic use among US NICUs, which seems partially explained by patient case-mix. Additional studies are needed to identify drivers of unwarranted variability in antibiotic use among NICUs. DisclosuresRitu Banerjee, MD, PhD, Accelerate Diagnostics: Grant/Research Support; BioFire: Research Grant; Biomerieux: Research Grant; Roche: Research Grant.

1126. Variability in Antibiotic Use in Children’s Hospitals in the United States

BackgroundUnderstanding patterns of inpatient antibiotic use is necessary to enhance appropriate use and minimize preventable harm at hospitals. Few studies have characterized antibiotic use in the inpatient setting in children.MethodsWe conducted a cross-sectional study in children admitted to 51 freestanding US children’s hospitals included in the Pediatric Health Information System (PHIS). Overall and broad-spectrum antibiotic use (see Table) were measured using charge data, and prevalence of use was assessed on a single day of each 2017–2018 season over one year. Comparisons were made based on clinical setting (medical vs. surgical), clinical unit (PICU, NICU, and all others), hospital, and region. We assessed the relationship between antibiotic use and median hospital case-mix index (CMI), a surrogate for clinical complexity.ResultsOf 52769 hospitalized children assessed on a study day, 19174 (36%) received antibiotics, and 6575 (12%) received broad-spectrum antibiotics (table). Overall antibiotic use prevalence varied across hospitals from 22% to 52% (Figure 1). Median hospital CMI had no significant relationship with overall antibiotic use and only a weak correlation (ρ=0.29) with broad-spectrum antibiotic use (Figure 2). Antibiotic use prevalence varied minimally by season, ranging from 36% in fall to 37% in summer. Antibiotic use prevalence was 29% (9470/32436) among medical patients and 48% (9704/20333) among surgical patients. The antibiotics most commonly administered in medical patients were ceftriaxone and ampicillin, while surgical patients most commonly received cefazolin and vancomycin. Regional prevalence ranged from 33% (Midwest) to 40% (West). By unit, PICU patients had the highest prevalence of overall [58% (4006/6874)] and broad-spectrum [27% (1830/6874)] antibiotic use. Children with complex chronic conditions accounted for 63% of hospitalized children but represented 72% of children receiving any antibiotic and 85% of those receiving broad-spectrum antibiotics.ConclusionWe observed large and apparently unexplained variability in antibiotic use prevalence among children’s hospitals, clinical settings, and regions. This indicates potential opportunities for enhanced antibiotic stewardship activities. DisclosuresRitu Banerjee, MD, PhD, Accelerate Diagnostics: Grant/Research Support; BioFire: Research Grant; Biomerieux: Research Grant; Roche: Research Grant

Regional variability in outpatient antibiotic use in Ontario, Canada: a retrospective cross-sectional study.

Regional variability in antibiotic use is associated with both antibiotic overuse and antimicrobial resistance. Our objectives were to benchmark outpatient antibiotic use and to evaluate geographic variability among health regions in the province of Ontario, Canada. This was a cross-sectional study of antibiotics dispensed from outpatient retail pharmacies in Ontario between March 2016 and February 2017. We analyzed variability in the number of antibiotic prescriptions dispensed per 1000 population among Ontario's 14 health regions with crude and adjusted Poisson regression models. Adjusted models controlled for rurality, 4 physician characteristics and 6 population characteristics. There were 8 352 578 antibiotics dispensed during the 1-year study period or 621 per 1000 population. The most commonly prescribed antibiotic classes were narrow-spectrum penicillins, macrolides, first-generation cephalosporins and second-generation fluoroquinolones, with adult women receiving the highest rate of prescriptions: 985 antibiotic prescriptions per 1000 population. There was geographic variability in total and class-specific antibiotic use. In the health region with the highest use 778 antibiotics were dispensed per 1000 population whereas in the health region with the lowest use 534 antibiotics were dispensed per 1000 population. The adjusted marginal standardized antibiotic prescription rates for the health regions with the highest and lowest use were 787 (95% confidence interval [CI] 658-934) and 546 (95% CI 494-606) antibiotic prescriptions per 1000 population, respectively. We described baseline antibiotic usage in Ontario over a 12-month period, noting variability among some health regions. Our findings highlight the need for interventions to optimize antibiotic use and slow the emergence of antimicrobial resistance.

Assessing the impact of antibiotic stewardship program elements on antibiotic use across acute-care hospitals: an observational study.

Antibiotic use varies widely between hospitals, but the influence of antimicrobial stewardship programs (ASPs) on this variability is not known. We aimed to determine the key structural and strategic aspects of ASPs associated with differences in risk-adjusted antibiotic utilization across facilities. Observational study of acute-care hospitals in Ontario, Canada METHODS: A survey was sent to hospitals asking about both structural (8 elements) and strategic (32 elements) components of their ASP. Antibiotic use from hospital purchasing data was acquired for January 1 to December 31, 2014. Crude and adjusted defined daily doses per 1,000 patient days, accounting for hospital and aggregate patient characteristics, were calculated across facilities. Rate ratios (RR) of defined daily doses per 1,000 patient days were compared for hospitals with and without each antimicrobial stewardship element of interest. Of 127 eligible hospitals, 73 (57%) participated in the study. There was a 7-fold range in antibiotic use across these facilities (min, 253 defined daily doses per 1,000 patient days; max, 1,872 defined daily doses per 1,000 patient days). The presence of designated funding or resources for the ASP (RRadjusted, 0·87; 95% CI, 0·75-0·99), prospective audit and feedback (RRadjusted, 0·80; 95% CI, 0·67-0·96), and intravenous-to-oral conversion policies (RRadjusted, 0·79; 95% CI, 0·64-0·99) were associated with lower risk-adjusted antibiotic use. Wide variability in antibiotic use across hospitals may be partially explained by both structural and strategic ASP elements. The presence of funding and resources, prospective audit and feedback, and intravenous-to-oral conversion should be considered priority elements of a robust ASP.

Examination of high-antibiotic users in a multi-institutional cohort of chronic rhinosinusitis patients.

In addition to known concerns regarding antibiotic overuse, recent research indicates that excessive antibiotic use is associated with poorer long-term health. Given that rhinosinusitis is the leading condition accounting for antibiotic prescriptions in the ambulatory setting, we aimed to evaluate characteristics associated with greater antibiotic use in chronic rhinosinusitis (CRS). Adult CRS patients enrolled in a prospective, multi-institutional, observational cohort study evaluating treatment outcomes were included in this analysis. Study participants were asked to report the number of days out of the previous 90 days that systemic antibiotics were taken for sinus disease. Patient demographics, disease characteristics, and measures of disease severity were evaluated. A total of 561 patients from 4 institutions were included in the analysis, with mean antibiotic use of 17.4 ± 22.4 out of the prior 90 days. No differences between antibiotic-use groups were found for objective measures of disease severity (computed tomography [CT], endoscopy, Brief Smell Identification Test [BSIT] scores), however, increased patient-reported symptom burden (22-item Sino-Nasal Outcome Test [SNOT-22], Rhinosinusitis Disability Index [RSDI]) was associated with more antibiotic use. Patients reporting the most antibiotic use were older (p = 0.004) but no ethnic or gender differences were seen. Comorbid diagnoses of allergy, asthma, diabetes, depression, or fibromyalgia were not associated with increased antibiotic use. In accordance with literature recommendations, CRS with nasal polyps (CRSwNP) patients were less likely to have used antibiotics. Endoscopic sinus surgery (ESS) significantly decreased antibiotic use. Variability in antibiotic use in CRS appears to be driven by symptom burden, independent of objective measures of disease severity, patient demographics, and presence of comorbid disease. Clear guidelines are essential to define appropriate antibiotic use in CRS.

Variability in antibiotic use across Ontario acute care hospitals.

Antibiotic stewardship is a required organizational practice for Canadian acute care hospitals, yet data are scarce regarding the quantity and composition of antibiotic use across facilities. We sought to examine the variability, and risk-adjusted variability, in antibiotic use across acute care hospitals in Ontario, Canada's most populous province. Antibiotic purchasing data from IMS Health, previously demonstrated to correlate strongly with internal antibiotic dispensing data, were acquired for 129 Ontario hospitals from January to December 2014 and linked to patient day (PD) denominator data from administrative datasets. Hospital variation in DDDs/1000 PDs was determined for overall antibiotic use, class-specific use and six practices of clinical or ecological significance. Multivariable risk adjustment for hospital and patient characteristics was used to compare observed versus expected utilization. There was 7.4-fold variability in the quantity of antibiotic use across the 129 acute care hospitals, from 253 to 1873 DDDs/1000 PDs. Variation was evident within hospital subtypes, exceeded that explained by hospital and patient characteristics, and included wide variability in proportion of broad-spectrum antibiotics (IQR 36%-48%), proportion of fluoroquinolones among respiratory antibiotics (IQR 40%-62%), proportion of ciprofloxacin among urinary anti-infectives (IQR 44%-60%), proportion of antibiotics with highest risk for Clostridium difficile (IQR 29%-40%), proportion of 'reserved-use' antibiotics (IQR 0.8%-3.5%) and proportion of anti-pseudomonal antibiotics among antibiotics with Gram-negative coverage (IQR 26%-40%). There is extensive variability in antibiotic use, and risk-adjusted use, across acute care hospitals. This could motivate, focus and benchmark antibiotic stewardship efforts.

Variability in Antibiotic Use in Pediatric Intensive Care Units

Variability in Antibiotic Use in Pediatric Intensive Care Units

Variability in Antibiotic Use Across Nursing Homes and the Risk of Antibiotic-Related Adverse Outcomes for Individual Residents.

Antibiotics are frequently and often inappropriately prescribed to patients in nursing homes. These antibiotics pose direct risks to recipients and indirect risks to others residing in the home. To examine whether living in a nursing home with high antibiotic use is associated with an increased risk of antibiotic-related adverse outcomes for individual residents. In this longitudinal open-cohort study performed from January 1, 2010, through December 31, 2011, we studied 110,656 older adults residing in 607 nursing homes in Ontario, Canada. Nursing home-level antibiotic use was defined as use-days per 1000 resident-days, and facilities were classified as high, medium, and low use according to tertile of use. Multivariable logistic regression modeling was performed to assess the effect of nursing home-level antibiotic use on the individual risk of antibiotic-related adverse outcomes. Antibiotic-related harms included Clostridium difficile, diarrhea or gastroenteritis, antibiotic-resistant organisms (which can directly affect recipients and indirectly affect nonrecipients), allergic reactions, and general medication adverse events (which can affect only recipients). Antibiotics were provided on 2,783,000 of 50,953,000 resident-days in nursing homes (55 antibiotic-days per 1000 resident-days). Antibiotic use was highly variable across homes, ranging from 20.4 to 192.9 antibiotic-days per 1000 resident-days. Antibiotic-related adverse events were more common (13.3%) in residents of high-use homes than among residents of medium-use (12.4%) or low-use homes (11.4%) (P < .001); this trend persisted even among the residents who did not receive antibiotic treatments. The primary analysis indicated that residence in a high-use nursing home was associated with an increased risk of a resident experiencing an antibiotic-related adverse event (adjusted odds ratio, 1.24; 95% CI, 1.07-1.42; P = .003). A sensitivity analysis examining nursing home-level antibiotic use as a continuous variable confirmed an increased risk of resident-level antibiotic-related harms (adjusted odds ratio, 1.004 per additional day of nursing home antibiotic use; 95% CI, 1.001-1.006; P = .01). Antibiotic use is highly variable across nursing homes; residents of high-use homes are exposed to an increased risk of antibiotic-related harms even if they have not directly received these agents. Antibiotic stewardship is needed to improve the safety of all nursing home residents.

Trends and Seasonal Variation in Outpatient Antibiotic Prescription Rates in the United States, 2006 to 2010

Antibiotic-resistant bacteria are an increasing threat to the effectiveness of antibiotics. The majority of antibiotics are prescribed in primary care settings for upper respiratory tract infections. The purpose of this study was to describe seasonal trends in outpatient antibiotic prescriptions (Rx) in the United States over a 5-year period. This study was a retrospective, cross-sectional observation of systemic antibiotic prescriptions in the outpatient setting from 2006 to 2010. Winter months were defined as the first and fourth quarters of the calendar year. Antibiotic prescribing rates were calculated (prescriptions/1,000 population) using annual U.S. Census Bureau population data. Over 1.34 billion antibiotic prescriptions were dispensed over the 5-year period. The antibiotic prescription (Rx) rate decreased from 892 Rx/1,000 population in 2006 to 867 Rx/1,000 population in 2010. Penicillins and macrolides were the primary antibiotic classes prescribed, but penicillin prescribing decreased while macrolide prescribing increased over the study period. Overall, antibiotic prescriptions were 24.5% higher in winter months than in the summer, with the largest difference (28.8%) in 2008 and the smallest (20.4%) in 2010. This seasonality was consistently drug class dependent, driven by 75% and 100% increases in penicillin and macrolide prescriptions, respectively, in the winter months. The mean outpatient antibiotic prescription rate decreased in the United States from 2006 to 2010. More antibiotic prescribing, predominately driven by the macrolide and penicillin classes, in the outpatient setting was observed in the winter months. Understanding annual variability in antibiotic use can assist with designing interventions to improve the judicious use of antibiotics.

Antibiotic prescriptions in the paediatric population in the Lazio Region of Italy: association with children's and physician's characteristics.

Estimating prevalence rates for antibacterial use in 0-14 year old children in 2009 in Lazio (Italy). Antibiotic prescriptions has been selected as drugs belonging to the J01 main therapeutic of the Anatomical Therapeutic Chemical system. Prevalence data by sex and age were calculated. The proportion of children who underwent 1, 2 or ≥ 3 treatments was calculated. Relation between use of antibiotics and incidence of influenza cases was evaluated. The association of children's and physician's characteristics with prescription was assessed by multi-level Poisson regression model. 45% of children received one antibiotic with a peak in the 1-2 age. Penicillins combinations and beta-lactamase inhibitors were the most frequently prescribed group. Multilevel model highlighted prescription rate decreases with doctor's increasing age, if the doctor is a paediatrician and female. Contrarily, doctors with >900 patients present higher probability to prescribe antibiotics. The study highlights the variability in antibiotic use and the fact that several children's and primary care doctors' characteristics are associated with antibiotic prescription. Paper findings appear to be coherent with other Italian studies but prevalence rate is definitively higher comparing to other countries.

Identifying Targets for Antimicrobial Stewardship in Children's Hospitals

Antimicrobial stewardship programs (ASPs) are recommended to optimize antimicrobial use for hospitalized patients. Although mechanisms for the implementation of ASPs have been described, data-driven approaches to prioritize specific conditions and antimicrobials for intervention have not been established. We aimed to develop a strategy for identifying high-impact targets for antimicrobial stewardship efforts. Retrospective cross-sectional study. Children admitted to 32 freestanding children's hospitals in the United States in 2010. We identified the conditions with the largest proportional contribution to the total days of antibiotic therapy prescribed to all hospitalized children. For the 4 highest-using conditions, we examined variability between hospitals in antibiotic selection patterns for use of either first- or second-line therapies depending on the condition. Antibiotic use was determined using standardized probability of exposure to selected agents and standardized days of therapy per 1,000 patient-days, adjusting for patient demographics and severity of illness. In 2010, 524,364 children received 2,082,929 days of antibiotic therapy. Surgical patients received 43% of all antibiotics. The 4 highest-using conditions-pneumonia, appendicitis, cystic fibrosis, and skin and soft-tissue infection-represent 1% of all conditions yet accounted for more than 10% of all antibiotic use. Wide variability in antibiotic use occurred for 3 of these 4 conditions. Antibiotic use in children's hospitals varied broadly across institutions when examining diagnoses individually and adjusting for severity of illness. Identifying conditions with both frequent and variable antimicrobial use informs the prioritization of high-impact targets for future antimicrobial stewardship interventions.

Variation in hospital antibiotic prescribing practices for children with acute lymphoblastic leukemia

Antibiotic variation among pediatric oncology patients has not been well-described. Identification of significant variability in antibiotic use within this population would warrant evaluation of its clinical impact. We conducted a retrospective cohort study of newly diagnosed patients with pediatric acute lymophoblastic leukemia (ALL) hospitalized from 1999 to 2009 in 39 freestanding US children's hospitals within the Pediatric Health Information System. Medication use data were obtained for the first 30 days from each patient's index ALL admission date. Antibiotic exposure rates were reported as antibiotic days/1000 hospital days. Unadjusted composite broad-spectrum antibiotic exposure rates varied from 577 to 1628 antibiotic days/1000 hospital days. This wide range of antibiotic exposure was unaffected by adjustment for age, gender, race and days of severe illness (adjusted range: 532–1635 days of antibiotic therapy/1000 hospital days). Antibiotic use for children with newly diagnosed ALL varies widely across children's hospitals and is not explained by demographics or illness severity.

Antibiotic use in long-term care facilities

Evaluation and optimization of antibiotic use (antibiotic stewardship) is being increasingly promoted as a means to reduce antibiotic resistance, adverse events, treatment complications and costs within institutions. Our goal was to examine the prevalence of antibiotic use among long-term care facility residents and the extent of variability across these institutions. We conducted a population-based, point-prevalence study of antibiotic use among elderly individuals (n = 37,371) residing in long-term care facilities (n = 363 institutions) in Ontario between April and June 2009, using linked healthcare databases from Canada's largest province. Facilities were grouped into quintiles according to their mean antibiotic dispensing rates and variation was compared across quintiles. There were 2190 (5.9%) long-term care residents receiving antibiotic prescriptions on the study date. The three most prevalent antibiotics were agents most commonly used for the treatment of urinary tract infections, including nitrofurantoin (365, 15.4%), trimethoprim/sulfamethoxazole (338, 14.3%) and ciprofloxacin (304, 12.8%). The majority of treatment courses were at least 10 days in duration (1482, 62.6%), and many exceeded 90 days (495, 20.9%), suggesting chronic prophylaxis. There was substantial variability in antibiotic use across facilities, with a 5-fold variation from the highest-use quintile (10.8%) to the lowest-use quintile (2.2%). This variation persisted after adjustment for multiple facility-level and resident-level factors, including demographic characteristics, healthcare utilization statistics, co-morbidity prevalence, functional status and device dependence. Antibiotic use is common among long-term care residents, variable across institutions, and may benefit from focused antimicrobial stewardship interventions to standardize treatment indications and duration.

Antibiotic use in adult outpatients in Switzerland in relation to regions, seasonality and point of care tests

The use of antibiotics is highest in primary care and directly associated with antibiotic resistance in the community. We assessed regional variations in antibiotic use in primary care in Switzerland and explored prescription patterns in relation to the use of point of care tests. Defined daily doses of antibiotics per 1000 inhabitants (DDD1000pd) were calculated for the year 2007 from reimbursement data of the largest Swiss health insurer, based on the anatomic therapeutic chemical classification and the DDD methodology recommended by WHO. We present ecological associations by use of descriptive and regression analysis. We analysed data from 1 067 934 adults, representing 17.1% of the Swiss population. The rate of outpatient antibiotic prescriptions in the entire population was 8.5 DDD1000pd, and varied between 7.28 and 11.33 DDD1000pd for northwest Switzerland and the Lake Geneva region. DDD1000pd for the three most prescribed antibiotics were 2.90 for amoxicillin and amoxicillin-clavulanate, 1.77 for fluoroquinolones, and 1.34 for macrolides. Regions with higher DDD1000pd showed higher seasonal variability in antibiotic use and lower use of all point of care tests. In regression analysis for each class of antibiotics, the use of any point of care test was consistently associated with fewer antibiotic prescriptions. Prescription rates of primary care physicians showed variations between Swiss regions and were lower in northwest Switzerland and in physicians using point of care tests. Ecological studies are prone to bias and whether point of care tests reduce antibiotic use has to be investigated in pragmatic primary care trials.