A framework for inferring and analyzing pharmacotherapy treatment patterns.

BACKGROUND: To discover pharmacotherapy prescription patterns and their statistical associations with outcomes through a clinical pathway inference framework applied to real-world data. METHODS: We apply machine learning steps in our framework using a 2006 to 2020 cohort of veterans with major depressive disorder (MDD). Outpatient antidepressant pharmacy fills, dispensed inpatient antidepressant medications, emergency department visits, self-harm, and all-cause mortality data were extracted from the Department of Veterans Affairs Corporate Data Warehouse. RESULTS: Our MDD cohort consisted of 252,179 individuals. During the study period there were 98,417 emergency department visits, 1,016 cases of self-harm, and 1,507 deaths from all causes. The top ten prescription patterns accounted for 69.3% of the data for individuals starting antidepressants at the fluoxetine equivalent of 20-39 mg. Additionally, we found associations between outcomes and dosage change. CONCLUSIONS: For 252,179 Veterans who served in Iraq and Afghanistan with subsequent MDD noted in their electronic medical records, we documented and described the major pharmacotherapy prescription patterns implemented by Veterans Health Administration providers. Ten patterns accounted for almost 70% of the data. Associations between antidepressant usage and outcomes in observational data may be confounded. The low numbers of adverse events, especially those associated with all-cause mortality, make our calculations imprecise. Furthermore, our outcomes are also indications for both disease and treatment. Despite these limitations, we demonstrate the usefulness of our framework in providing operational insight into clinical practice, and our results underscore the need for increased monitoring during critical points of treatment.

Active Surveillance and Contact Precautions for Preventing Methicillin-Resistant Staphylococcus aureus Healthcare-Associated Infections During the COVID-19 Pandemic.

BACKGROUND: Statistically significant decreases in methicillin-resistant Staphylococcus aureus (MRSA) healthcare-associated infections (HAIs) occurred in Veterans Affairs (VA) hospitals from 2007 to 2019 using a national policy of active surveillance (AS) for facility admissions and contact precautions for MRSA colonized (CPC) or infected (CPI) patients, but the impact of suspending these measures to free up laboratory resources for testing and conserve personal protective equipment for coronavirus disease 2019 (COVID-19) on MRSA HAI rates is not known. METHODS: From July 2020 to June 2022 all 123 acute care VA hospitals nationwide were given the rolling option to suspend (or re-initiate) any combination of AS, CPC, or CPI each month, and MRSA HAIs in intensive care units (ICUs) and non-ICUs were tracked. RESULTS: There were 917 591 admissions, 5 225 174 patient-days, and 568 MRSA HAIs. The MRSA HAI rate/1000 patient-days in ICUs was 0.20 (95% confidence interval [CI], .15-.26) for facilities practicing "AS + CPC + CPI" compared to 0.65 (95% CI, .41-.98; P < .001) for those not practicing any of these strategies, and in non-ICUs was 0.07 (95% CI, .05-.08) and 0.12 (95% CI, .08-.19; P = .01) for the respective policies. Accounting for monthly COVID-19 facility admissions using a negative binomial regression model did not change the relationships between facility policy and MRSA HAI rates. There was no significant difference in monthly facility urinary catheter-associated infection rates, a non-equivalent dependent variable, in the policy categories in either ICUs or non-ICUs. CONCLUSIONS: Facility removal of MRSA prevention practices was associated with higher rates of MRSA HAIs in ICUs and non-ICUs.

Optimal Urine Culture Diagnostic Stewardship Practice-Results from an Expert Modified-Delphi Procedure.

BACKGROUND: Urine cultures are nonspecific and often lead to misdiagnosis of urinary tract infection and unnecessary antibiotics. Diagnostic stewardship is a set of procedures that modifies test ordering, processing, and reporting in order to optimize diagnosis and downstream treatment. In this study, we aimed to develop expert guidance on best practices for urine culture diagnostic stewardship. METHODS: A RAND-modified Delphi approach with a multidisciplinary expert panel was used to ascertain diagnostic stewardship best practices. Clinical questions to guide recommendations were grouped into three thematic areas (ordering, processing, reporting) in practice settings of emergency department, inpatient, ambulatory, and long-term care. Fifteen experts ranked recommendations on a 9-point Likert scale. Recommendations on which the panel did not reach agreement were discussed during a virtual meeting, then a second round of ranking by email was completed. After secondary review of results and panel discussion, a series of guidance statements was developed. RESULTS: One hundred and sixty-five questions were reviewed. The panel reaching agreement on 104, leading to 18 overarching guidance statements. The following strategies were recommended to optimize ordering urine cultures: requiring documentation of symptoms, sending alerts to discourage ordering in the absence of symptoms, and cancelling repeat cultures. For urine culture processing, conditional urine cultures and urine white blood cell count as criteria were supported. For urine culture reporting, appropriate practices included nudges to discourage treatment under specific conditions and selective reporting of antibiotics to guide therapy decisions. CONCLUSIONS: These 18 guidance statements can optimize use of urine cultures for better patient outcomes.

Trends in Illness Severity, Hospitalization, and Mortality for Community-Onset Pneumonia at 118 US Veterans Affairs Medical Centers.

BACKGROUND: Deaths from pneumonia were decreasing globally prior to the COVID-19 pandemic, but it is unclear whether this was due to changes in patient populations, illness severity, diagnosis, hospitalization thresholds, or treatment. Using clinical data from the electronic health record among a national cohort of patients initially diagnosed with pneumonia, we examined temporal trends in severity of illness, hospitalization, and short- and long-term deaths. DESIGN: Retrospective cohort PARTICIPANTS: All patients >18 years presenting to emergency departments (EDs) at 118 VA Medical Centers between 1/1/2006 and 12/31/2016 with an initial clinical diagnosis of pneumonia and confirmed by chest imaging report. EXPOSURES: Year of encounter. MAIN MEASURES: Hospitalization and 30-day and 90-day mortality. Illness severity was defined as the probability of each outcome predicted by machine learning predictive models using age, sex, comorbidities, vital signs, and laboratory data from encounters during years 2006-2007, and similar models trained on encounters from years 2015 to 2016. We estimated the changes in hospitalizations and 30-day and 90-day mortality between the first and the last 2 years of the study period accounted for by illness severity using time covariate decompositions with model estimates. RESULTS: Among 196,899 encounters across the study period, hospitalization decreased from 71 to 63%, 30-day mortality 10 to 7%, 90-day mortality 16 to 12%, and 1-year mortality 29 to 24%. Comorbidity risk increased, but illness severity decreased. Decreases in illness severity accounted for 21-31% of the decrease in hospitalizations, and 45-47%, 32-24%, and 17-19% of the decrease in 30-day, 90-day, and 1-year mortality. Findings were similar among underrepresented patients and those with only hospital discharge diagnosis codes. CONCLUSIONS: Outcomes for community-onset pneumonia have improved across the VA healthcare system after accounting for illness severity, despite an increase in cases and comorbidity burden.

Pre-endoscopy coronavirus disease 2019 screening and severe acute respiratory syndrome coronavirus-2 nucleic acid amplification testing in the Veterans Affairs healthcare system: clinical practice patterns, outcomes, and relationship to procedure volume.

BACKGROUND AND AIMS: The coronavirus disease 2019 (COVID-19) pandemic has had profound impacts worldwide, including on the performance of GI endoscopy. We aimed to describe the performance and outcomes of pre-endoscopy COVID-19 symptom and exposure screening and severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) nucleic acid amplification testing (NAAT) across the national Veterans Affairs healthcare system and describe the relationship of SARS-CoV-2 NAAT use and resumption of endoscopy services. METHODS: COVID-19 screening and NAAT results from March 2020 to April 2021 were analyzed to determine use, performance characteristics of screening, and association between testing and endoscopic volume trends. RESULTS: Of 220,891 completed endoscopies identified, 115,890 (52.5%) had documented preprocedure COVID-19 symptom and exposure screenings and 154,127 (69.8%) had preprocedure NAAT results within 7 days before scheduled endoscopy. Of 131,894 total canceled endoscopies, 26,475 (20.1%) had screening data and 28,505 (21.6%) had SARS-CoV-2 NAAT results. Overall, positive NAAT results were reported in 1.8% of all individuals tested and in 1.3% of those who screened negative. Among completed and canceled endoscopies, COVID-19 screening had a 34.6% sensitivity (95% confidence interval [CI], 32.4%-36.8%) and 96.4% specificity (95% CI, 96.2%-96.5%) when compared with NAAT. COVID-19 screening had a positive predictive value of 15.0% (95% CI, 14.0%-16.1%) and a negative predictive value of 98.7% (95% CI, 98.7%-98.8%). There was a very weak correlation between monthly testing and monthly endoscopy volume by site (Spearman rank correlation coefficient = .09). CONCLUSIONS: These findings have important implications for decisions about preprocedure testing, especially given breakthrough infections among vaccinated individuals during the SARS-CoV-2 delta and omicron variant surge.

Epidemiology and outcomes associated with carbapenem-resistant Acinetobacter baumannii and carbapenem-resistant Pseudomonas aeruginosa: a retrospective cohort study.

BACKGROUND: Carbapenem-resistant Acinetobacter baumannii (CRAB) and carbapenem-resistant Pseudomonas aeruginosa (CRPA) are a growing threat. The objective of this study was to describe CRAB and CRPA epidemiology and identify factors associated with mortality and length of stay (LOS) post-culture. METHODS: This was a national retrospective cohort study of Veterans with CRAB or CRPA positive cultures from 2013 to 2018, conducted at Hines Veterans Affairs Hospital. Carbapenem resistance was defined as non-susceptibility to imipenem, meropenem and/or doripenem. Multivariable cluster adjusted regression models were fit to assess the association of post-culture LOS among inpatient and long-term care (LTC) and to identify factors associated with 90-day and 365-day mortality after positive CRAB and CRPA cultures. RESULTS: CRAB and CRPA were identified in 1,048 and 8,204 unique patients respectively, with 90-day mortality rates of 30.3% and 24.5% and inpatient post-LOS of 26 and 27 days. Positive blood cultures were associated with an increased odds of 90-day mortality compared to urine cultures in patients with CRAB (OR 6.98, 95% CI 3.55-13.73) and CRPA (OR 2.82, 95% CI 2.04-3.90). In patients with CRAB and CRPA blood cultures, higher Charlson score was associated with increased odds of 90-day mortality. In CRAB and CRPA, among patients from inpatient care settings, blood cultures were associated with a decreased LOS compared to urine cultures. CONCLUSIONS: Positive blood cultures and more comorbidities were associated with higher odds for mortality in patients with CRAB and CRPA. Recognizing these factors would encourage clinicians to treat these patients in a timely manner to improve outcomes of patients infected with these organisms.

A flexible framework for visualizing and exploring patient misdiagnosis over time.

Diagnosis is a complex and ambiguous process and yet, it is the critical hinge point for all subsequent clinical reasoning and decision-making. Tracking the quality of the patient diagnostic process has the potential to provide valuable insights in improving the diagnostic accuracy and to reduce downstream errors but needs to be informative, timely, and efficient at scale. However, due to the rate at which healthcare data are captured on a daily basis, manually reviewing the diagnostic history of each patient would be a severely taxing process without efficient data reduction and representation. Application of data visualization and visual analytics to healthcare data is one promising approach for addressing these challenges. This paper presents a novel flexible visualization and analysis framework for exploring the patient diagnostic process over time (i.e., patient diagnosis paths). Our framework allows users to select a specific set of patients, events and/or conditions, filter data based on different attributes, and view further details on the selected patient cohort while providing an interactive view of the resulting patient diagnosis paths. A practical demonstration of our system is presented with a case study exploring infection-based patient diagnosis paths.

Attributable Cost of Healthcare-Associated Methicillin-Resistant Staphylococcus aureus Infection in a Long-term Care Center.

BACKGROUND: Studies have shown that healthcare-associated infections (HAIs) due to methicillin-resistant Staphylococcus aureus (MRSA) can lead to substantial healthcare costs in acute care settings. However, little is known regarding the consequences of these infections on patients in long-term care centers (LTCCs). The purpose of this study was to estimate the attributable cost of MRSA HAIs in LTCCs within the Department of Veterans Affairs (VA). METHODS: We performed a retrospective cohort study of patients admitted to VA LTCCs between 1 January 2009 and 30 September 2015. MRSA HAIs were defined as a positive clinical culture at least 48 hours after LTCC admission so as to exclude community-acquired infections. Positive cultures were further classified by site (sterile or nonsterile). We used multivariable generalized linear models and 2-part models to compare the LTCC and acute care costs between patients with and without an MRSA HAI. RESULTS: In our primary analysis, there was no difference in LTCC costs between patients with and without a MRSA HAI. There was, however, a significant increase in the odds of being transferred to an acute care facility (odds ratio, 4.40 [95% confidence interval {CI}, 3.40-5.67]) and in acute care costs ($9711 [95% CI, $6961-$12 462]). CONCLUSIONS: Our findings of high cost and increased risk of transfer from LTCC to acute care are important because they highlight the substantial clinical and economic impact of MRSA infections in this population.

Risk Factors Associated With Carbapenemase-Producing Carbapenem-Resistant Enterobacteriaceae Positive Cultures in a Cohort of US Veterans.

BACKGROUND: Carbapenem-resistant Enterobacteriaceae (CRE) cause approximately 13 100 infections, with an 8% mortality rate in the United States annually. Carbapenemase-producing CRE (CP-CRE) a subset of CRE infections infections have much higher mortality rates (40%-50%). There has been little research on characteristics unique to CP-CRE. The goal of the current study was to assess differences between US veterans with non-CP-CRE and those with CP-CRE cultures. METHODS: A retrospective cohort of veterans with CRE cultures from 2013-2018 and their demographic, medical, and facility level covariates were collected. Clustered multiple logistic regression models were used to assess independent factors associated with CP-CRE. RESULTS: The study included 3096 unique patients with cultures positive for either non-CP-CRE or CP-CRE. Being African American (odds ratio, 1.44 [95% confidence interval, 1.15-1.80]), diagnosis in 2017 (3.11 [2.13-4.54]) or 2018 (3.93 [2.64-5.84]), congestive heart failure (1.35 [1.11-1.64]), and gastroesophageal reflux disease (1.39 [1.03-1.87]) were associated with CP-CRE cultures. There was no known antibiotic exposure in the previous year for 752 patients (24.3% of the included patients). Those with no known antibiotic exposure had increased frequency of prolonged proton pump inhibitor use (17.3%) compared to those with known antibiotic exposure (5.6%). DISCUSSION: Among a cohort of patients with CRE, African Americans, patients with congestive heart failure, and those with gastroesophageal reflux disease had greater odds of having a CP-CRE culture. Roughly 1 in 4 patients with CP-CRE had no known antibiotic exposure in the year before their positive culture.

Expanding an Economic Evaluation of the Veterans Affairs (VA) Methicillin-resistant Staphylococcus aureus (MRSA) Prevention Initiative to Include Prevention of Infections From Other Pathogens.

BACKGROUND: In October 2007, Veterans Affairs (VA) launched a nationwide effort to reduce methicillin-resistant Staphylococcus aureus (MRSA) transmission called the National MRSA Prevention Initiative. Although the initiative focused on MRSA, recent evidence suggests that it also led to a significant decrease in hospital-onset (HO) gram-negative rod (GNR) bacteremia, vancomycin-resistant Enterococci (VRE), and Clostridioides difficile infections. The objective of this analysis was to evaluate the cost-effectiveness and the budget impact of the initiative taking into account MRSA, GNR, VRE, and C. difficile infections. METHODS: We developed an economic model using published data on the rate of MRSA hospital-acquired infections (HAIs) and HO-GNR bacteremia in the VA from October 2007 to September 2015, estimates of the attributable cost and mortality of these infections, and the costs associated with the intervention obtained through a microcosting approach. We explored several different assumptions for the rate of infections that would have occurred if the initiative had not been implemented. Effectiveness was measured in life-years (LYs) gained. RESULTS: We found that during fiscal years 2008-2015, the initiative resulted in an estimated 4761-9236 fewer MRSA HAIs, 1447-2159 fewer HO-GNR bacteremia, 3083-3602 fewer C. difficile infections, and 2075-5393 fewer VRE infections. The initiative itself was estimated to cost $561 million over this 8-year period, whereas the cost savings from prevented MRSA HAIs ranged from $165 to $315 million and from prevented HO-GNR bacteremia, CRE and C. difficile infections ranged from $174 to $200 million. The incremental cost-effectiveness of the initiative ranged from $12 146 to $38 673/LY when just including MRSA HAIs and from $1354 to $4369/LY when including the additional pathogens. The overall impact on the VA's budget ranged from $67 to$195 million. CONCLUSIONS: An MRSA surveillance and prevention strategy in VA may have prevented a substantial number of infections from MRSA and other organisms. The net increase in cost from implementing this strategy was quite small when considering infections from all types of organisms. Including spillover effects of organism-specific prevention efforts onto other organisms can provide a more comprehensive evaluation of the costs and benefits of these interventions.

Simulated Adoption of 2019 Community-Acquired Pneumonia Guidelines Across 114 Veterans Affairs Medical Centers: Estimated Impact on Culturing and Antibiotic Selection in Hospitalized Patients.

BACKGROUND: The 2019 American Thoracic Society/Infectious Diseases Society of America guidelines for community-acquired pneumonia (CAP) revised recommendations for culturing and empiric broad-spectrum antibiotics. We simulated guideline adoption in Veterans Affairs (VA) inpatients. METHODS: For all VA acute hospitalizations for CAP from 2006-2016 nationwide, we compared observed with guideline-expected proportions of hospitalizations with initial blood and respiratory cultures obtained, empiric antibiotic therapy with activity against methicillin-resistant Staphylococcus aureus (anti-MRSA) or Pseudomonas aeruginosa (antipseudomonal), empiric "overcoverage" (receipt of anti-MRSA/antipseudomonal therapy without eventual detection of MRSA/P. aeruginosa on culture), and empiric "undercoverage" (lack of anti-MRSA/antipseudomonal therapy with eventual detection on culture). RESULTS: Of 115 036 CAP hospitalizations over 11 years, 17 877 (16%) were admitted to an intensive care unit (ICU). Guideline adoption would slightly increase respiratory culture (30% to 36%) and decrease blood culture proportions (93% to 36%) in hospital wards and increase both respiratory (40% to 100%) and blood (95% to 100%) cultures in ICUs. Adoption would decrease empiric selection of anti-MRSA (ward: 27% to 1%; ICU: 61% to 8%) and antipseudomonal (ward: 25% to 1%; ICU: 54% to 9%) therapies. This would correspond to greatly decreased MRSA overcoverage (ward: 27% to 1%; ICU: 56% to 8%), slightly increased MRSA undercoverage (ward: 0.6% to 1.3%; ICU: 0.5% to 3.3%), with similar findings for P. aeruginosa. For all comparisons, P < .001. CONCLUSIONS: Adoption of the 2019 CAP guidelines in this population would substantially change culturing and empiric antibiotic selection practices, with a decrease in overcoverage and slight increase in undercoverage for MRSA and P. aeruginosa.

ReHouSED: A novel measurement of Veteran housing stability using natural language processing.

Housing stability is an important determinant of health. The US Department of Veterans Affairs (VA) administers several programs to assist Veterans experiencing unstable housing. Measuring long-term housing stability of Veterans who receive assistance from VA is difficult due to a lack of standardized structured documentation in the Electronic Health Record (EHR). However, the text of clinical notes often contains detailed information about Veterans' housing situations that may be extracted using natural language processing (NLP). We present a novel NLP-based measurement of Veteran housing stability: Relative Housing Stability in Electronic Documentation (ReHouSED). We first develop and evaluate a system for classifying documents containing information about Veterans' housing situations. Next, we aggregate information from multiple documents to derive a patient-level measurement of housing stability. Finally, we demonstrate this method's ability to differentiate between Veterans who are stably and unstably housed. Thus, ReHouSED provides an important methodological framework for the study of long-term housing stability among Veterans receiving housing assistance.

Use of Oral Vancomycin for Clostridioides difficile Infection and the Risk of Vancomycin-Resistant Enterococci.

BACKGROUND: Vancomycin is now a preferred treatment for all cases of Clostridioides difficile infection (CDI), regardless of disease severity. Concerns remain that a large-scale shift to oral vancomycin may increase selection pressure for vancomycin-resistant Enterococci (VRE). We evaluated the risk of VRE following oral vancomycin or metronidazole treatment among patients with CDI. METHODS: We conducted a retrospective cohort study of patients with CDI in the US Department of Veterans Affairs health system between 1 January 2006 and 31 December 2016. Patients were included if they were treated with metronidazole or oral vancomycin and had no history of VRE in the previous year. Missing data were handled by multiple imputation of 50 datasets. Patients treated with oral vancomycin were compared to those treated with metronidazole after balancing on patient characteristics using propensity score matching in each imputed dataset. Patients were followed for VRE isolated from a clinical culture within 3 months. RESULTS: Patients treated with oral vancomycin were no more likely to develop VRE within 3 months than metronidazole-treated patients (adjusted relative risk, 0.96; 95% confidence interval [CI], .77 to 1.20), equating to an absolute risk difference of -0.11% (95% CI, -.68% to .47%). Similar results were observed at 6 months. CONCLUSIONS: Our results suggest that oral vancomycin and metronidazole are equally likely to impact patients' risk of VRE. In the setting of stable CDI incidence, replacement of metronidazole with oral vancomycin is unlikely to be a significant driver of increased risk of VRE at the patient level.In this multicenter, retrospective cohort study of patients with Clostridioides difficile infection, the use of oral vancomycin did not increase the risk of vancomycin-resistant Enterococci infection at 3 or 6 months compared to metronidazole.

Decreases in Antimicrobial Use Associated With Multihospital Implementation of Electronic Antimicrobial Stewardship Tools.

BACKGROUND: Antimicrobial stewards may benefit from comparative data to inform interventions that promote optimal inpatient antimicrobial use. METHODS: Antimicrobial stewards from 8 geographically dispersed Veterans Affairs (VA) inpatient facilities participated in the development of antimicrobial use visualization tools that allowed for comparison to facilities of similar complexity. The visualization tools consisted of an interactive web-based antimicrobial dashboard and, later, a standardized antimicrobial usage report updated at user-selected intervals. Stewards participated in monthly learning collaboratives. The percent change in average monthly antimicrobial use (all antimicrobial agents, anti-methicillin-resistant Staphylococcus aureus [anti-MRSA] agents, and antipseudomonal agents) was analyzed using a pre-post (January 2014-January 2016 vs July 2016-January 2018) design with segmented regression and external comparison with uninvolved control facilities (n = 118). RESULTS: Intervention sites demonstrated a 2.1% decrease (95% confidence interval [CI], -5.7% to 1.6%) in total antimicrobial use pre-post intervention vs a 2.5% increase (95% CI, 0.8% to 4.1%) in nonintervention sites (absolute difference, 4.6%; P = .025). Anti-MRSA antimicrobial use decreased 11.3% (95% CI, -16.0% to -6.3%) at intervention sites vs a 6.6% decrease (95% CI, -9.1% to -3.9%) at nonintervention sites (absolute difference, 4.7%; P = .092). Antipseudomonal antimicrobial use decreased 3.4% (95% CI, -8.2% to 1.7%) at intervention sites vs a 3.6% increase (95% CI, 0.8% to 6.5%) at nonintervention sites (absolute difference, 7.0%; P = .018). CONCLUSIONS: Comparative data visualization tool use by stewards at 8 VA facilities was associated with significant reductions in overall antimicrobial and antipseudomonal use relative to uninvolved facilities.

Multidrug-resistant gram-negative organisms and association with 1-year mortality, readmission, and length of stay in Veterans with spinal cord injuries and disorders.

STUDY DESIGN: Retrospective cohort study. OBJECTIVES: The goal of this study was to assess the impact of multidrug resistant gram-negative organisms (MDRGNOs) on outcomes in those with SCI/D. SETTING: VA SCI System of Care, Department of Veterans Affairs, United States. METHODS: Multidrug resistance (MDR) was defined as being non-susceptible to ≥1 antibiotic in ≥3 antibiotic classes. Multivariable cluster-adjusted regression models were fit to assess the association of MDRGNOs with 1-year mortality, 30-day readmission, and postculture length of stay (LOS) stratified by case setting patients. Only the first culture per patient during the study period was included. RESULTS: A total of 8,681 individuals with SCI/D had a culture with gram-negative bacteria during the study period, of which 33.0% had a MDRGNO. Overall, 954 (10.9%) died within 1 year of culture date. Poisson regression showed that MDR was associated with 1-year mortality among outpatients (IRR: 1.28, 95% CI, 1.06-1.54) and long-term care patients (OR: 2.06, 95% CI, 1.28-3.31). MDR significantly impacted postculture LOS in inpatients, as evidenced by a 10% longer LOS in MDR vs. non-MDR (IRR: 1.10, 95% CI, 1.02-1.19). MDR was not associated with increased 30-day readmission. CONCLUSIONS: MDRGNOs are prevalent in SCI/D and MDR may result in poor outcomes. Further attention to prevention of infections, antibiotic stewardship, and management are warranted in this population.

Methicillin-resistant Staphylococcus aureus Colonization and Pre- and Post-hospital Discharge Infection Risk.

Background: The Department of Veterans Affairs implemented an active surveillance program for methicillin-resistant Staphylococcus aureus (MRSA) in 2007 in which acute care inpatients are tested for MRSA carriage on admission, unit-to-unit transfer, and discharge. Using these data, we followed patients longitudinally to estimate the difference in infection rates for those who were not colonized, those who were colonized on admission (importers), and those who acquired MRSA during their stay. We examined MRSA infections that occurred prior to discharge and at 30, 90, 180, and 365 days after discharge. Methods: We constructed a dataset of 985626 first admissions from January 2008 through December 2015 who had surveillance tests performed for MRSA carriage. We performed multivariable Cox proportional hazards and logistic regression models to examine the relationship between MRSA colonization status and infection. Results: The MRSA infection rate across the predischarge and 180-day postdischarge time period was 5.5% in importers and 7.0% in acquirers without a direct admission to the intensive care unit (ICU) and 11.4% in importers and 11.7% in acquirers who were admitted directly to the ICU. The predischarge hazard ratio for MRSA infection was 29.6 (95% confidence interval [CI], 26.5-32.9) for importers and 28.8 (95% CI, 23.5-35.3) for acquirers compared to those not colonized. Fully 63.9% of all MRSA pre- and postdischarge infections among importers and 61.2% among acquirers occurred within 180 days after discharge. Conclusions: MRSA colonization significantly increases the risk of subsequent MRSA infection. In addition, a substantial proportion of MRSA infections occur after discharge from the hospital.

Vital Signs: Trends in Staphylococcus aureus Infections in Veterans Affairs Medical Centers - United States, 2005-2017.

INTRODUCTION: By 2007, all Department of Veterans Affairs medical centers (VAMCs) had initiated a multifaceted methicillin-resistant Staphylococcus aureus (MRSA) prevention program. MRSA and methicillin-susceptible S. aureus (MSSA) infection rates among VAMC inpatients from 2005 to 2017 were assessed. METHODS: Clinical microbiology data from any patient admitted to an acute-care VAMC in the United States from 2005 through 2017 and trends in hospital-acquired MRSA colonization were examined. RESULTS: S. aureus infections decreased by 43% overall during the study period (p<0.001), driven primarily by decreases in MRSA, which decreased by 55% (p<0.001), whereas MSSA decreased by 12% (p = 0.003). Hospital-onset MRSA and MSSA infections decreased by 66% (p<0.001) and 19% (p = 0.02), respectively. Community-onset MRSA infections decreased by 41% (p<0.001), whereas MSSA infections showed no significant decline. Acquisition of MRSA colonization decreased 78% during 2008-2017 (17% annually, p<0.001). MRSA infection rates declined more sharply among patients who had negative admission surveillance MRSA screening tests (annual 9.7% decline) compared with those among patients with positive admission MRSA screening tests (4.2%) (p<0.05). CONCLUSIONS AND IMPLICATIONS FOR PUBLIC HEALTH PRACTICE: Significant reductions in S. aureus infection following the VAMC intervention were led primarily by decreases in MRSA. Moreover, MRSA infection declines were much larger among patients not carrying MRSA at the time of admission than among those who were. Taken together, these results suggest that decreased MRSA transmission played a substantial role in reducing overall S. aureus infections at VAMCs. Recent calls to withdraw infection control interventions designed to prevent MRSA transmission might be premature and inadvisable, at least until more is known about effective control of bacterial pathogen transmission in health care settings. Effective S. aureus prevention strategies require a multifaceted approach that includes adherence to current CDC recommendations for preventing not only device- and procedure-associated infections, but also transmission of health care-prevalent strains.

Attributable Cost and Length of Stay Associated with Nosocomial Gram-Negative Bacterial Cultures.

Few studies have estimated the excess inpatient costs due to nosocomial cultures of Gram-negative bacteria (GNB), and those that do are often subject to time-dependent bias. Our objective was to generate estimates of the attributable costs of the underlying infections associated with nosocomial cultures by using a unique inpatient cost data set from the U.S. Department of Veterans Affairs that allowed us to reduce time-dependent bias. Our study included data from inpatient admissions between 1 October 2007 and 30 November 2010. Nosocomial GNB-positive cultures were defined as clinical cultures positive for Acinetobacter, Pseudomonas, or Enterobacteriaceae between 48 h after admission and discharge. Positive cultures were further classified by site and level of resistance. We conducted analyses using both a conventional approach and an approach aimed at reducing the impact of time-dependent bias. In both instances, we used multivariable generalized linear models to compare the inpatient costs and length of stay for patients with and without a nosocomial GNB culture. Of the 404,652 patients included in the conventional analysis, 12,356 had a nosocomial GNB-positive culture. The excess costs of nosocomial GNB-positive cultures were significant, regardless of specific pathogen, site, or resistance level. Estimates generated using the conventional analysis approach were 32.0% to 131.2% greater than those generated using the approach to reduce time-dependent bias. These results are important because they underscore the large financial burden attributable to these infections and provide a baseline that can be used to assess the impact of improvements in infection control.

Specifying an implementation framework for Veterans Affairs antimicrobial stewardship programmes: using a factor analysis approach.

Objectives: Inappropriate antibiotic use poses a serious threat to patient safety. Antimicrobial stewardship programmes (ASPs) may optimize antimicrobial use and improve patient outcomes, but their implementation remains an organizational challenge. Using the Promoting Action on Research Implementation in Health Services (PARiHS) framework, this study aimed to identify organizational factors that may facilitate ASP design, development and implementation. Methods: Among 130 Veterans Affairs facilities that offered acute care, we classified organizational variables supporting antimicrobial stewardship activities into three PARiHS domains: evidence to encompass sources of knowledge; contexts to translate evidence into practice; and facilitation to enhance the implementation process. We conducted a series of exploratory factor analyses to identify conceptually linked factor scales. Cronbach's alphas were calculated. Variables with large uniqueness values were left as single factors. Results: We identified 32 factors, including six constructs derived from factor analyses under the three PARiHS domains. In the evidence domain, four factors described guidelines and clinical pathways. The context domain was broken into three main categories: (i) receptive context (15 factors describing resources, affiliations/networks, formalized policies/practices, decision-making, receptiveness to change); (ii) team functioning (1 factor); and (iii) evaluation/feedback (5 factors). Within facilitation, two factors described facilitator roles and tasks and five captured skills and training. Conclusions: We mapped survey data onto PARiHS domains to identify factors that may be adapted to facilitate ASP uptake. Our model encompasses mostly mutable factors whose relationships with performance outcomes may be explored to optimize antimicrobial use. Our framework also provides an analytical model for determining whether leveraging existing organizational processes can potentially optimize ASP performance.

In Data We Trust? Comparison of Electronic Versus Manual Abstraction of Antimicrobial Prescribing Quality Metrics for Hospitalized Veterans With Pneumonia.

BACKGROUND: Electronic health records provide the opportunity to assess system-wide quality measures. Veterans Affairs Pharmacy Benefits Management Center for Medication Safety uses medication use evaluation (MUE) through manual review of the electronic health records. OBJECTIVE: To compare an electronic MUE approach versus human/manual review for extraction of antibiotic use (choice and duration) and severity metrics. RESEARCH DESIGN: Retrospective. SUBJECTS: Hospitalizations for uncomplicated pneumonia occurring during 2013 at 30 Veterans Affairs facilities. MEASURES: We compared summary statistics, individual hospitalization-level agreement, facility-level consistency, and patterns of variation between electronic and manual MUE for initial severity, antibiotic choice, daily clinical stability, and antibiotic duration. RESULTS: Among 2004 hospitalizations, electronic and manual abstraction methods showed high individual hospitalization-level agreement for initial severity measures (agreement=86%-98%, κ=0.5-0.82), antibiotic choice (agreement=89%-100%, κ=0.70-0.94), and facility-level consistency for empiric antibiotic choice (anti-MRSA r=0.97, P<0.001; antipseudomonal r=0.95, P<0.001) and therapy duration (r=0.77, P<0.001) but lower facility-level consistency for days to clinical stability (r=0.52, P=0.006) or excessive duration of therapy (r=0.55, P=0.005). Both methods identified widespread facility-level variation in antibiotic choice, but we found additional variation in manual estimation of excessive antibiotic duration and initial illness severity. CONCLUSIONS: Electronic and manual MUE agreed well for illness severity, antibiotic choice, and duration of therapy in pneumonia at both the individual and facility levels. Manual MUE showed additional reviewer-level variation in estimation of initial illness severity and excessive antibiotic use. Electronic MUE allows for reliable, scalable tracking of national patterns of antimicrobial use, enabling the examination of system-wide interventions to improve quality.