Daniel J. Livorsi

Comparative Effectiveness of Cefazolin Versus Nafcillin or Oxacillin for Treatment of Methicillin-Susceptible Staphylococcus aureus Infections Complicated by Bacteremia: A Nationwide Cohort Study

Background To treat patients with methicillin-susceptible Staphylococcus aureus (MSSA) infections, β-lactams are recommended for definitive therapy; however, the comparative effectiveness of individual β-lactams is unknown. This study compared definitive therapy with cefazolin vs nafcillin or oxacillin among patients with MSSA infections complicated by bacteremia. Methods This retrospective study included patients admitted to 119 Veterans Affairs hospitals from 2003 to 2010. Patients were included if they had a blood culture positive for MSSA and received definitive therapy with cefazolin, nafcillin, or oxacillin. Cox proportional hazards regression and ordinal logistic regression were used to identify associations between antibiotic therapy and mortality or recurrence. A recurrent infection was defined as a MSSA blood culture between 45 and 365 days after the first MSSA blood culture. Results Of 3167 patients, 1163 (37%) patients received definitive therapy with cefazolin. Patients who received cefazolin had a 37% reduction in 30-day mortality (hazard ratio [HR], 0.63; 95% confidence interval [CI], .51-.78) and a 23% reduction in 90-day mortality (HR, 0.77; 95% CI, .66-.90) compared with patients receiving nafcillin or oxacillin, after controlling for other factors. The odds of recurrence (odds ratio, 1.13; 95% CI, .94-1.36) were similar among patients who received cefazolin compared with patients who received nafcillin or oxacillin, after controlling for other factors. Conclusions In this large, multicenter study, patients who received cefazolin had a lower risk of mortality and similar odds of recurrent infections compared with nafcillin or oxacillin for MSSA infections complicated by bacteremia. Physicians might consider definitive therapy with cefazolin for these infections.

Association of Evidence-Based Care Processes With Mortality in Staphylococcus aureus Bacteremia at Veterans Health Administration Hospitals, 2003-2014

Importance Staphylococcus aureus bacteremia is common and frequently associated with poor outcomes. Evidence indicates that specific care processes are associated with improved outcomes for patients with S aureus bacteremia, including appropriate antibiotic prescribing, use of echocardiography to identify endocarditis, and consultation with infectious diseases (ID) specialists. Whether use of these care processes has increased in routine care for S aureus bacteremia or whether use of these processes has led to large-scale improvements in survival is unknown. Objective To examine the association of evidence-based care processes in routine care for S aureus bacteremia with mortality. Design, Setting, and Participants This retrospective observational cohort study examined all patients admitted to Veterans Health Administration (VHA) acute care hospitals who had a first episode of S aureus bacteremia from January 1, 2003, through December 31, 2014. Exposures Use of appropriate antibiotic therapy, echocardiography, and ID consultation. Main Outcomes and Measures Thirty-day all-cause mortality. Results Analyses included 36 868 patients in 124 hospitals (mean [SD] age, 66.4 [12.5] years; 36 036 [97.7%] male), including 19 325 (52.4%) with infection due to methicillin-resistant S aureus and 17 543 (47.6%) with infection due to methicillin-susceptible S aureus. Risk-adjusted mortality decreased from 23.5% (95% CI, 23.3%-23.8%) in 2003 to 18.2% (95% CI, 17.9%-18.5%) in 2014. Rates of appropriate antibiotic prescribing increased from 2467 (66.4%) to 1991 (78.9%), echocardiography from 1256 (33.8%) to 1837 (72.8%), and ID consultation from 1390 (37.4%) to 1717 (68.0%). After adjustment for patient characteristics, cohort year, and other care processes, receipt of care processes was associated with lower mortality, with adjusted odds ratios of 0.74 (95% CI, 0.68-0.79) for appropriate antibiotics, 0.73 (95% CI, 0.68-0.78) for echocardiography, and 0.61 (95% CI, 0.56-0.65) for ID consultation. Mortality decreased progressively as the number of care processes that a patient received increased (adjusted odds ratio for all 3 processes compared with none, 0.33; 95% CI, 0.30-0.36). An estimated 57.3% (95% CI, 48.4%-69.9%) of the decrease in mortality between 2003 and 2014 could be attributed to increased use of these evidence-based care processes. Conclusions and Relevance Mortality associated with S aureus bacteremia decreased significantly in VHA hospitals, and a substantial portion of the decreasing mortality may have been attributable to increased use of evidence-based care processes. The experience in VHA hospitals demonstrates that increasing application of these care processes may improve survival among patients with S aureus bacteremia in routine health care settings.

The Effect of a Nationwide Infection Control Program Expansion on Hospital-Onset Gram-Negative Rod Bacteremia in 130 Veterans Health Administration Medical Centers: An Interrupted Time-Series Analysis

BACKGROUND The Veterans Health Administration (VHA) introduced the Methicillin-Resistant Staphylococcus aureus (MRSA) Prevention Initiative in March 2007. Although the initiative has been perceived as a vertical intervention focusing on MRSA, it also expanded infection prevention and control programs and resources. We aimed to assess the horizontal effect of the initiative on hospital-onset (HO) gram-negative rod (GNR) bacteremia. METHODS This retrospective cohort included all patients who had HO bacteremia due to Escherichia coli, Klebsiella species, or Pseudomonas aeruginosa at 130 VHA facilities from January 2003 to December 2013. The effects were assessed using segmented linear regression with autoregressive error models, incorporating autocorrelation, immediate effect, and time before and after the initiative. Community-acquired (CA) bacteremia with same species was also analyzed as nonequivalent dependent controls. RESULTS A total of 11 196 patients experienced HO-GNR bacteremia during the study period. There was a significant change of slope in HO-GNR bacteremia incidence rates from before the initiative (+0.3%/month) to after (-0.4%/month) (P < .01), while CA GNR incidence rates did not significantly change (P = .08). Cumulative effect of the intervention on HO-GNR bacteremia incidence rates at the end of the study period was estimated to be -43.2% (95% confidence interval, -51.6% to -32.4%). Similar effects were observed in subgroup analyses of each species and antimicrobial susceptibility profile. CONCLUSIONS Within 130 VHA facilities, there was a sustained decline in HO-GNR bacteremia incidence rates after the implementation of the MRSA Prevention Initiative. As these organisms were not specifically targeted, it is likely that horizontal components of the initiative contributed to this decline.

Audit and Feedback Processes Among Antimicrobial Stewardship Programs: A Survey of the Society for Healthcare Epidemiology of America Research Network.

Optimal implementation of audit-and-feedback is an important part of advancing antimicrobial stewardship programs. Our survey demonstrated variability in how 61 programs approach audit-and-feedback. The median (interquartile range) number of recommendations per week was 9 (5-19) per 100 hospital-beds. A major perceived barrier to more comprehensive stewardship was lack of resources. Infect Control Hosp Epidemiol 2016;37:704-706.

A Novel Metric to Monitor the Influence of Antimicrobial Stewardship Activities

The antimicrobial use (AU) option within the National Healthcare Safety Network summarizes antimicrobial prescribing data as a standardized antimicrobial administration ratio (SAAR). A hospitals antimicrobial stewardship program found that greater involvement of an infectious disease physician in prospective audit and feedback procedures was associated with reductions in SAAR values across multiple antimicrobial categories. Infect Control Hosp Epidemiol 2017;38:721-723.

Developing Local Treatment Guidelines for Healthcare-Associated Pneumonia

TO THE EDITOR—We read with interest the meta-analysis by Chalmers et al [1], which demonstrates that the healthcareassociated pneumonia (HCAP) definition poorly predicts the presence of resistant pathogens. Based on these findings, the authors encourage treatment for HCAP to be guided by the local prevalence of multidrug-resistant pathogens. In hopes of constructing a local syndromic antibiogram specific to HCAP, we retrospectively identified inpatients treated for pneumonia at our facility, the Richard L. Roudebush VA Medical Center, between 1 January 2011 and 31 December 2012. The Roudebush center is a tertiary care facility that provides complete medical care for 85 000 adults in Indianapolis, Indiana. Potential cases were identified by the following International Classification of Diseases, Ninth Revision codes: 480.0–480.9, 481, 482.0– 482.9, 483.0–483.8, 484.1–484.8, 485, 486, and 487. All medical records were reviewed, and only cases that met criteria for HCAP were selected for further analysis [2]. A total of 113 cases of HCAP were identified; 98% of patients were men, and the mean age was 71 years. Blood cultures were obtained in 103 patients (91%), sputum cultures in 47 (42%), and bronchoalveolar lavage specimens in 2 (2%). The sputum specimen was graded as good in 15 (32%), fair in 29 (62%), and poor in 3 (6%). At least 1 microbiologic pathogen was identified by either blood or respiratory samples in only 26 cases (23%). Enterobacteriaceae were isolated in 10 cases (38%), methicillinsusceptible Staphylococcus aureus in 5 (19%), Pseudomonas aeruginosa in 4 (15%), Streptococcus pneumoniae in 4 (15%), and methicillin-resistant S. aureus (MRSA) in 3 (12%). Although we collected 2 years of data, our sample size of culture-positive cases (n = 26) was small. The culture-positive rate of 23% is similar to that in several other HCAP studies [3–7]. This low culture-positive rate may reflect both the difficulty of collecting sputum samples in nonventilated patients and the poor quality of the samples that were collected [8]. To augment our limited microbiologic data, we have also monitored clinical outcomes inpatientswhohadnomicrobiologic

Implementation of a mobile clinical decision support application to augment local antimicrobial stewardship

Background: Medical applications for mobile devices allow clinicians to leverage microbiological data and standardized guidelines to treat patients with infectious diseases. We report the implementation of a mobile clinical decision support (CDS) application to augment local antimicrobial stewardship. Methods: We detail the implementation of our mobile CDS application over 20 months. Application utilization data were collected and evaluated using descriptive statistics to quantify the impact of our implementation. Results: Project initiation focused on engaging key stakeholders, developing a business case, and selecting a mobile platform. The preimplementation phase included content development, creation of a pathway for content approval within the hospital committee structure, engaging clinical leaders, and formatting the first version of the guide. Implementation involved a media campaign, staff education, and integration within the electronic medical record and hospital mobile devices. The postimplementation phase required ongoing quality improvement, revision of outdated content, and repeated staff education. The evaluation phase included a guide utilization analysis, reporting to hospital leadership, and sustainability and innovation planning. The mobile application was downloaded 3056 times and accessed 9259 times during the study period. The companion web viewer was accessed 8214 times. Conclusions: Successful implementation of a customizable mobile CDS tool enabled our team to expand beyond microbiological data to clinical diagnosis, treatment, and antimicrobial stewardship, broadening our influence on antimicrobial prescribing and incorporating utilization data to inspire new quality and safety initiatives. Further studies are needed to assess the impact on antimicrobial utilization, infection control measures, and patient care outcomes.

Research Agenda for Antimicrobial Stewardship in the Veterans Health Administration

Author(s): Suda, Katie J; Livorsi, Daniel J; Goto, Michihiko; Forrest, Graeme N; Jones, Makoto M; Neuhauser, Melinda M; Hoff, Brian M; Ince, Dilek; Carrel, Margaret; Nair, Rajeshwari; Knobloch, Mary Jo; Goetz, Matthew B

Identifying Opportunities to Improve Guideline-Concordant Antibiotic Prescribing in Veterans with Acute Respiratory Infections or Cystitis

We investigated the frequency and determinants of guideline-discordant antibiotic prescribing in outpatients with respiratory infections or cystitis. Antibiotic prescribing was guideline discordant in 60% of patients. The most common reason for discordance was prescribing an antibiotic when not indicated. In a multivariate analysis, physicians in training had the highest likelihood of guideline-concordant antibiotic prescribing. Infect Control Hosp Epidemiol 2017;38:724-728.

Antimicrobial Nonsusceptibility of Gram-Negative Bloodstream Isolates, Veterans Health Administration System, United States, 2003–20131

Bacteremia caused by gram-negative bacteria is associated with serious illness and death, and emergence of antimicrobial drug resistance in these bacteria is a major concern. Using national microbiology and patient data for 2003–2013 from the US Veterans Health Administration, we characterized nonsusceptibility trends of community-acquired, community-onset; healthcare-associated, community-onset; and hospital-onset bacteremia for selected gram-negative bacteria (Escherichia coli, Klebsiella spp., Pseudomonas aeruginosa, and Acinetobacter spp.). For 47,746 episodes of bacteremia, the incidence rate was 6.37 episodes/10,000 person-years for community-onset bacteremia and 4.53 episodes/10,000 patient-days for hospital-onset bacteremia. For Klebsiella spp., P. aeruginosa, and Acinetobacter spp., we observed a decreasing proportion of nonsusceptibility across nearly all antimicrobial drug classes for patients with healthcare exposure; trends for community-acquired, community-onset isolates were stable or increasing. The role of infection control and antimicrobial stewardship efforts in inpatient settings in the decrease in drug resistance rates for hospital-onset isolates needs to be determined.