To evaluate the impact of implementing a clinical care guideline for uncomplicated gram-negative bloodstream infections (GN-BSI) within a health system.

Retrospective, quasi-experimental study.

A large academic safety-net institution.

Adults (≥18 years) with GN-BSI, defined by at least one positive blood culture for specific gram-negative organisms. Patients with polymicrobial cultures or contaminants were excluded.

Implementation of a GN-BSI clinical care guideline based on a 2021 consensus statement, emphasizing 7-day antibiotic courses, use of highly bioavailable oral antibiotics, and minimizing repeat blood cultures.

The study included 147 patients pre-intervention and 169 post-intervention. Interrupted time series analysis showed a reduction in the median duration of therapy (–2.3 days, P = .0016), with a sustained decline (slope change –0.2103, P = .005) post-intervention. More patients received 7 days of therapy (12.9%–58%, P < .01), oral antibiotic transitions increased (57.8% vs 72.2%, P < .05), and guideline-concordant oral antibiotic selection was high. Repeat blood cultures decreased (50.3% vs 30.2%, P < .01) without an increase in recurrent bacteremia. No significant differences were observed in 90-day length of stay, rehospitalization, recurrence, or mortality.

Guideline implementation was associated with shorter antibiotic therapy durations, increased use of guideline-concordant oral antibiotics, and fewer repeat blood cultures without compromising patient outcomes. These findings support the effectiveness of institutional guidelines in standardizing care, optimizing resource utilization, and promoting evidence-based practices in infectious disease management.

For most common infections requiring hospitalization, antibiotic treatment is completed after hospital discharge. Postdischarge therapy is often unnecessarily broad spectrum and prolonged. We developed an intervention to improve antibiotic selection and shorten treatment durations.

Single center, quasi-experimental retrospective cohort study

Patients prescribed oral antibiotics at hospital discharge before (July 2012–June 2013) and after (October 2014–February 2015) an intervention consisting of (1) institutional guidance for oral step-down antibiotic selection and duration of therapy and (2) pharmacy audit of discharge prescriptions with real-time prescribing recommendations to providers. The primary outcomes measured were total prescribed duration of therapy and use of antibiotics with broad gram-negative activity (ie, fluoroquinolones or amoxicillin-clavulanate).

Overall, 300 cases from the preintervention period and 200 cases from the intervention period were included. Compared with the preintervention period, the use of antibiotics with broad gram-negative activity decreased during the intervention (51% vs 40%; P=.02), particularly fluoroquinolones (38% vs 25%; P=.002). The total duration of therapy decreased from a median of 10 days (interquartile range [IQR], 7–13 days) to 9 days (IQR, 6–13 days) but did not reach statistical significance (P=.13). However, the duration prescribed at discharge declined from 6 days (IQR, 4–10 days) to 5 days (IQR, 3–7 days) (P=.003). During the intervention, there was a nonsignificant increase in the overall appropriateness of discharge prescriptions from 52% to 66% (P=.15).

A multifaceted intervention to optimize antibiotic prescribing at hospital discharge was associated with less frequent use of antibiotics with broad gram-negative activity and shorter postdischarge treatment durations.

Infect Control Hosp Epidemiol 2017;38:534–541

To evaluate changes in outpatient fluoroquinolone (FQ) and nitrofurantoin (NFT) use and resistance among E. coli isolates after a change in institutional guidance to use NFT over FQs for acute uncomplicated cystitis.

Retrospective preintervention–postintervention study.

Urban, integrated healthcare system.

Adult outpatients treated for acute cystitis.

We compared 2 time periods: January 2003–June 2007 when FQs were recommended as first-line therapy, and July 2007–December 2012, when NFT was recommended. The main outcomes were changes in FQ and NFT use and FQ- and NFT-resistant E. coli by time-series analysis.

Overall, 5,714 adults treated for acute cystitis and 11,367 outpatient E. coli isolates were included in the analysis. After the change in prescribing guidance, there was an immediate 26% (95% CI, 20%–32%) decrease in FQ use (P<.001), and a nonsignificant 6% (95% CI, −2% to 15%) increase in NFT use (P=.12); these changes were sustained over the postintervention period. Oral cephalosporin use also increased during the postintervention period. There was a significant decrease in FQ-resistant E. coli of −0.4% per quarter (95% CI, −0.6% to −0.1%; P=.004) between the pre- and postintervention periods; however, a change in the trend of NFT-resistant E. coli was not observed.

In an integrated healthcare system, a change in institutional guidance for acute uncomplicated cystitis was associated with a reduction in FQ use, which may have contributed to a stabilization in FQ-resistant E. coli. Increased nitrofurantoin use was not associated with a change in NFT resistance.

Infect Control Hosp Epidemiol 2017;38:461–468

To evaluate the long-term outcomes of an antimicrobial stewardship program (ASP) implemented in a hospital with low baseline antibiotic use.

Quasi-experimental, interrupted time-series study.

Public safety net hospital with 525 beds.

Implementation of a formal ASP in July 2008.

We conducted a time-series analysis to evaluate the impact of the ASP over a 6.25-year period (July 1, 2008–September 30, 2014) while controlling for trends during a 3-year preintervention period (July 1, 2005–June 30, 2008). The primary outcome measures were total antibacterial and antipseudomonal use in days of therapy (DOT) per 1,000 patient-days (PD). Secondary outcomes included antimicrobial costs and resistance, hospital-onset Clostridium difficile infection, and other patient-centered measures.

During the preintervention period, total antibacterial and antipseudomonal use were declining (−9.2 and −5.5 DOT/1,000 PD per quarter, respectively). During the stewardship period, both continued to decline, although at lower rates (−3.7 and −2.2 DOT/1,000 PD, respectively), resulting in a slope change of 5.5 DOT/1,000 PD per quarter for total antibacterial use (P=.10) and 3.3 DOT/1,000 PD per quarter for antipseudomonal use (P=.01). Antibiotic expenditures declined markedly during the stewardship period (−$295.42/1,000 PD per quarter, P=.002). There were variable changes in antimicrobial resistance and few apparent changes in C. difficile infection and other patient-centered outcomes.

In a hospital with low baseline antibiotic use, implementation of an ASP was associated with sustained reductions in total antibacterial and antipseudomonal use and declining antibiotic expenditures. Common ASP outcome measures have limitations.

Infect Control Hosp Epidemiol 2015;00(0): 1–9

Hospitalizations for acute bacterial skin and skin structure infection (ABSSSI) are common. Optimizing antibiotic use for ABSSSIs requires an understanding of current management. The objective of this study was to evaluate antibiotic prescribing practices and factors affecting prescribing in a diverse group of hospitals

Multicenter, retrospective cohort study.

Seven community and academic hospitals.

Children and adults hospitalized between June 2010 and May 2012 for cellulitis, wound infection, or cutaneous abscess were eligible. The primary endpoint was a composite of 2 prescribing practices representing potentially avoidable antibiotic exposure: (1) use of antibiotics with a broad spectrum of activity against gram-negative bacteria or (2) treatment duration greater than 10 days.

A total of 533 cases were included: 320 with nonpurulent cellulitis, 44 with wound infection or purulent cellulitis, and 169 with abscess. Of 492 cases with complete prescribing data, the primary endpoint occurred in 394 (80%) cases and varied significantly across hospitals (64%–97%; P < .001). By logistic regression, independent predictors of the primary endpoint included wound infection or purulent cellulitis (odds ratio [OR], 5.12 [95% confidence interval (CI)], 1.46–17.88), head or neck involvement (OR, 2.83 [95% CI, 1.17–6.82]), adult cases (OR, 2.20 [95% CI, 1.18–4.11]), and admission to a community hospital (OR, 1.90 [95% CI, 1.05–3.44]).

Among patients hospitalized for ABSSSI, use of antibiotics with broad gram-negative activity or treatment courses longer than 10 days were common. There may be substantial opportunity to reduce antibiotic exposure through shorter courses of therapy targeting gram-positive bacteria.

Infect Control Hosp Epidemiol 2014;35(10):1241–1250

To describe the epidemiology of bloodstream infection caused by USA300 strains of methicillin-resistant Staphylococcus aureus (MRSA), which are traditionally associated with cases of community-acquired infection, in the healthcare setting.

Retrospective cohort study.

Three academically affiliated hospitals in Denver, Colorado.

Review of cases of S. aureus bloodstream infection during the period from 2003 through 2007. Polymerase chain reaction was used to identify MRSA USA300 isolates.

A total of 330 cases of MRSA bloodstream infection occurred during the study period, of which 286 (87%) were healthcare-associated. The rates of methicillin resistance among the S. aureus isolates recovered did not vary during the study period and were similar among the 3 hospitals. However, the percentages of cases of healthcare-associated MRSA bloodstream infection due to USA300 strains varied substantially among the 3 hospitals: 62%, 19%, and 36% (P < .001) for community-onset cases and 33%, 3%, and 33% (P = .005) for hospital-onset cases, in hospitals A, B, and C, respectively. In addition, the number of cases of healthcare-associated MRSA bloodstream infection caused by USA300 strains increased during the study period at 2 of the 3 hospitals. At each hospital, USA300 strains were most common among cases of community-associated infection and were least common among cases of hospital-onset infection. Admission to hospital A (a safety-net hospital), injection drug use, and human immunodeficiency virus infection were independent risk factors for healthcare-associated MRSA bloodstream infection due to USA300 strains.

The prevalence of USA300 strains among cases of healthcare-associated MRSA bloodstream infection varied dramatically among geographically clustered hospitals. USA300 strains are replacing traditional healthcare-related strains of MRSA in some healthcare settings. Our data suggest that the prevalence of USA300 strains in the community is the dominant factor affecting the prevalence of this strain type in the healthcare setting.