To determine antibiotic prescribing appropriateness for respiratory tract diagnoses (RTD) by season.

Retrospective cohort study.

Primary care practices in a university health system.

Patients who were seen at an office visit with diagnostic code for RTD.

Office visits for the entire cohort were categorized based on ICD-10 codes by the likelihood that an antibiotic was indicated (tier 1: always indicated; tier 2: sometimes indicated; tier 3: rarely indicated). Medical records were reviewed for 1,200 randomly selected office visits to determine appropriateness. Based on this reference standard, metrics and prescriber characteristics associated with inappropriate antibiotic prescribing were determined. Characteristics of antibiotic prescribing were compared between winter and summer months.

A significantly greater proportion of RTD visits had an antibiotic prescribed in winter [20,558/51,090 (40.2%)] compared to summer months [11,728/38,537 (30.4%)][standardized difference (SD) = 0.21]. A significantly greater proportion of winter compared to summer visits was associated with tier 2 RTDs (29.4% vs 23.4%, SD = 0.14), but less tier 3 RTDs (68.4% vs 74.4%, SD = 0.13). A greater proportion of visits in winter compared to summer months had an antibiotic prescribed for tier 2 RTDs (80.2% vs 74.2%, SD = 0.14) and tier 3 RTDs (22.9% vs 16.2%, SD = 0.17). The proportion of inappropriate antibiotic prescribing was higher in winter compared to summer months (72.4% vs 62.0%, P < .01).

Increases in antibiotic prescribing for RTD visits from summer to winter were likely driven by shifts in diagnoses as well as increases in prescribing for certain diagnoses. At least some of this increased prescribing was inappropriate.

Early administration of antibiotics in sepsis is associated with improved patient outcomes, but safe and generalizable approaches to de-escalate or discontinue antibiotics after suspected sepsis events are unknown.

We used a modified Delphi approach to identify safety criteria for an opt-out protocol to guide de-escalation or discontinuation of antibiotic therapy after 72 hours in non-ICU patients with suspected sepsis. An expert panel with expertise in antimicrobial stewardship and hospital epidemiology rated 48 unique criteria across 3 electronic survey rating tools. Criteria were rated primarily based on their impact on patient safety and feasibility for extraction from electronic health record review. The 48 unique criteria were rated by anonymous electronic survey tools, and the results were fed back to the expert panel participants. Consensus was achieved to either retain or remove each criterion.

After 3 rounds, 22 unique criteria remained as part of the opt-out safety checklist. These criteria included high-risk comorbidities, signs of severe illness, lack of cultures during sepsis work-up or antibiotic use prior to blood cultures, or ongoing signs and symptoms of infection.

The modified Delphi approach is a useful method to achieve expert-level consensus in the absence of evidence suifficient to provide validated guidance. The Delphi approach allowed for flexibility in development of an opt-out trial protocol for sepsis antibiotic de-escalation. The utility of this protocol should be evaluated in a randomized controlled trial.

To determine metrics and provider characteristics associated with inappropriate antibiotic prescribing for respiratory tract diagnoses (RTDs).

Retrospective cohort study.

Primary care practices in a university health system.

Patients seen by an attending physician or advanced practice provider (APP) at their primary care office visit with International Classification of Disease, Tenth Revision, Clinical Modification (ICD-10-CM)–coded RTDs.

Medical records were reviewed for 1,200 randomly selected office visits in which an antibiotic was prescribed to determine appropriateness. Based on this gold standard, metrics and provider characteristics associated with inappropriate antibiotic prescribing were determined.

Overall, 69% of antibiotics were inappropriate. Metrics utilizing prespecified RTDs most strongly associated with inappropriate prescribing were (1) proportion prescribing for RTDs for which antibiotics are almost never required (eg, bronchitis) and (2) proportion prescribing for any RTD. Provider characteristics associated with inappropriate antibiotic prescribing were APP versus physician (72% vs 58%; P = .02), family medicine versus internal medicine (76% vs 63%; P = .01), board certification 1997 or later versus board certification before 1997 (75% vs 63%; P = .02), nonteaching versus teaching practice (73% vs 51%; P < .01), and nonurban vs urban practice (77% vs 57%; P < .01).

Metrics utilizing proportion prescribing for RTDs for which antibiotics are almost never required and proportion prescribing for any RTD were most strongly associated with inappropriate prescribing. APPs and clinicians with family medicine training, with board certification 1997 or later, and who worked in nonteaching or nonurban practices had higher proportions of inappropriate prescribing. These findings could inform design of interventions to improve prescribing and could represent an efficient way to track inappropriate prescribing.

Fluoroquinolones (FQs) and extended-spectrum cephalosporins (ESCs) are associated with higher risk of Clostridioides difficile infection (CDI). Decreasing the unnecessary use of FQs and ESCs is a goal of antimicrobial stewardship. Understanding how prescribers perceive the risks and benefits of FQs and ESCs is needed.

We conducted interviews with clinicians from 4 hospitals. Interviews elicited respondent perceptions about the risk of ESCs, FQs, and CDI. Interviews were audio recorded, transcribed, and analyzed using a flexible coding approach.

Interviews were conducted with 64 respondents (38 physicians, 7 nurses, 6 advance practice providers, and 13 pharmacists). ESCs and FQs were perceived to have many benefits, including infrequent dosing, breadth of coverage, and greater patient adherence after hospital discharge. Prescribers stated that it was easy to make decisions about these drugs, so they were especially appealing to use in the context of time pressures. They described having difficulty discontinuing these drugs when prescribed by others due to inertia and fear. Prescribers were skeptical about targeting specific drugs as a stewardship approach and felt that the risk of a negative outcome from under treatment of a suspected bacterial infection was a higher priority than the prevention of CDI.

Prescribers in this study perceived many advantages to using ESCs and FQs, especially under conditions of time pressure and uncertainty. In making decisions about these drugs, prescribers balance risk and benefit, and they believed that the risk of CDI was acceptable in compared with the risk of undertreatment.

To describe the pattern of blood culture utilization in an academic university hospital setting.

Retrospective cohort study.

A 789-bed tertiary-care university hospital that processes 40,000+blood cultures annually.

We analyzed blood cultures collected from adult inpatients at the Hospital of the University of Pennsylvania between July 1, 2014, and June 30, 2015. Descriptive statistics and regression models were used to analyze patterns of blood culture utilization: frequency of blood cultures, use of repeat cultures following a true-positive culture, and number of sets drawn per day.

In total, 38,939 blood culture sets were drawn during 126,537 patient days (incidence rate, 307.7 sets per 1,000 patient days). The median number of blood culture sets drawn per hospital encounter was 2 (range, 1–76 sets). The median interval between blood cultures was 2 days (range, 1–71 days). Oncology services and cultures with gram-positive cocci were significantly associated with greater odds of having repeat blood cultures drawn the following day. Emergency services had the highest rate of drawing single blood-culture sets (16.9%), while oncology services had the highest frequency of drawing ≥5 blood culture sets within 24 hours (0.91%). Approximately 10% of encounters had at least 1 true-positive culture, and 89.2% of those encounters had repeat blood cultures drawn. The relative risk of a patient having repeat blood cultures was lower for those in emergency, surgery, and oncology services than for those in general medicine.

Ordering practices differed by service and culture results. Analyzing blood culture utilization can contribute to the development of guidelines and benchmarks for appropriate usage.

The decision to utilize antimicrobials in end-of-life situations is complex. Understanding the reasons why physicians prescribe antimicrobials in this patient population is important for informing the design of antimicrobial stewardship interventions.

A 51-item survey containing both closed and open-ended questions on end-of-life antimicrobial use was administered to physicians affiliated with the University of Pennsylvania and Children’s Hospital of Philadelphia from January through April 2017. A mixed-methods approach was used to analyze responses.

Of 637 physicians surveyed, 283 responses (44.4%) were received. Most (86.2%) physicians believed that respecting a patient’s wish to continue antimicrobials was important. Approximately half of physicians (49.8%) believed that antimicrobial use at the end of life contributes to resistance. A higher proportion of pediatricians would often or always continue antimicrobial treatment for active infections and for hospice patients whose death was imminent compared to adult physicians (P<.001). Analysis of free-text responses revealed additional reasons why physicians may continue antimicrobials at end of life, including meeting family expectations, wanting to avoid the perception of “giving up,” uncertainty about prognosis, and reducing patient pain or discomfort.

Physician decision making concerning antimicrobial use in patients at the end of life is multifactorial. Clinicians may overweigh the benefits of antimicrobial therapy in end-of-life situations and view the importance of adhering to stewardship policies differently. Pediatric and adult clinicians have different approaches to this patient population. Better understanding of the complex decision making that occurs in the end-of-life patient population can help guide antimicrobial stewardship policies and improve patient care.

Infect Control Hosp Epidemiol 2018;39:383–390

To evaluate the effectiveness of a computerized clinical decision support intervention aimed at reducing inappropriate Clostridium difficile testing

Retrospective cohort study

University of Pennsylvania Health System, comprised of 3 large tertiary-care hospitals

All adult patients admitted over a 2-year period

Providers were required to use an order set integrated into a commercial electronic health record to order C. difficile toxin testing. The order set identified patients who had received laxatives within the previous 36 hours and displayed a message asking providers to consider stopping laxatives and reassessing in 24 hours prior to ordering C. difficile testing. Providers had the option to continue or discontinue laxatives and to proceed with or forgo testing. The primary endpoint was the change in inappropriate C. difficile testing, as measured by the number of patients who had C. difficile testing ordered while receiving laxatives.

Compared to the 1-year baseline period, the intervention resulted in a decrease in the proportion of inappropriate C. difficile testing (29.6% vs 27.3%; P=.02). The intervention was associated with an increase in the number of patients who had laxatives discontinued and did not undergo C. difficile testing (5.8% vs 46.4%; P<.01) and who had their laxatives discontinued and underwent testing (5.4% vs 35.2%; P<.01). We observed a nonsignificant increase in the proportion of patients with C. difficile related complications (5.0% vs 8.9%; P=.11).

A C. difficile order set was successful in decreasing inappropriate C. difficile testing and improving the timely discontinuation of laxatives.

Infect Control Hosp Epidemiol 2017;38:1204–1208

To assess the likelihood of antimicrobial streamlining between 2 antimicrobial stewardship methods.

Retrospective cohort study.

Large academic medical center.

Frequency and time to antimicrobial streamlining were compared during a prior authorization and a prospective audit period. Streamlining was defined as an antimicrobial change to a narrower agent if available or to a broader agent if the isolate was resistant to empiric therapy. Patients included were ≥18 years old with monomicrobial bacteremia with S. aureus, Enterococcus spp., or any aerobic Gram-negative organism.

A total of 665 cases of bacteremia met inclusion criteria. Frequency of streamlining was similar between periods for all cases of bacteremia (audit vs restriction: 60.7% vs 53.2%; P=.12), S. aureus bacteremia (73.2% vs 76.9%; P=.671), and Enterococcus bacteremia (81.6% vs 71.9%; P=.335). Compared to restriction, the audit period was associated with an increased frequency of streamlining for cases of Gram-negative bacteremia (51.4% vs 35.6%; odds ratio [OR], 1.85; 95% confidence interval [CI], 1.06–3.25), those on the medical service (67.9% vs 53.1%; OR, 1.86; 95% CI, 1.09–3.16), and those admitted through the emergency department (71.6% vs 51.4%; OR, 2.32; 95% CI, 1.24–4.34). Characteristics associated with increased streamlining included: absence of β-lactam allergy (P<.001), Gram-negative bacteremia (P<.001), admission through the emergency department (P=.001), and admission to a medical service (P=.011).

Compared with prior authorization, prospective audit increased antimicrobial streamlining for cases of Gram-negative bacteremia, those admitted through the emergency department, and those admitted to a medical but not surgical service.

Infect Control Hosp Epidemiol 2016:1–7

To evaluate the association between hospital room square footage and acquisition of nosocomial Clostridium difficile infection (CDI).

A case-control study was conducted at a university hospital during the calendar year of 2011. Case patients were adult inpatients with nosocomial CDI. Control patients were hospitalized patients without CDI and were randomly selected and matched to cases in a 2:1 ratio on the basis of hospital length of stay in 3-day strata. A multivariate model was developed using conditional logistic regression to evaluate risk factors for nosocomial CDI.

A total of 75 case patients and 150 control patients were included. On multivariate analyses, greater square footage of the hospital room was associated with a significantly increased risk of acquiring CDI (odds ratio for every 50 ft2 increase, 3.00; 95% CI, 1.75–5.16; P<.001). Other factors associated with an increased risk of CDI were location in a single room (odds ratio, 3.43; 95% CI, 1.31–9.05; P=.01), malignant tumor (4.56; 1.82–11.4; P=.001), and receipt of cefepime (2.48; 1.06–5.82; P=.04) or immunosuppressants (6.90; 2.07–23.0; P=.002) within the previous 30 days.

Greater room square footage increased the risk of acquisition of CDI in the hospital setting, likely owing to increased environmental contamination and/or difficulty in effective disinfection. Future studies are needed to determine feasible and effective cleaning protocols based on patient and room characteristics.

Infect Control Hosp Epidemiol 2015;00(0): 1–5

In studies of the association between antibiotic-resistant infection and mortality, the importance of controlling for the underlying severity of illness is well recognized. However, it is unclear when the severity of illness should be assessed. Controlling for severity of illness on the day the culture specimen is obtained may underestimate the true association between resistance and mortality.

TO assess the impact of calculating the Acute Physiology and Chronic Health Evaluation (APACHE) II score at different time points on the association between antimicrobial resistance and mortality.

We used an existing data set from a study that investigated the association between fluoroquinolone resistance and mortality. The APACHE II score was calculated at 3 time points: the day the culture specimen was obtained, 1 day before the culture specimen was obtained, and 2 days before the culture specimen was obtained. Separate multivariable models were constructed using the 3 different APACHE II scores. These models were compared qualitatively.

Of 91 total subjects, 51 were infected with a fluoroquinolone-resistant strain and 40 with a fluoroquinolone-susceptible strain. The median APACHE II score for all subjects was 13 (95% confidence interval [CI], 11-15) when calculated on the day the culture specimen was obtained, 12 (95% CI, 11-13) when calculated 1 day before, and 11 (95% CI, 10-13) when calculated 2 days before the culture specimen was obtained. Of 91 subjects, 12 (13.2%) died. The 3 multivariable models (each with the APACHE II score calculated on a different day) were not substantively different; the adjusted odds ratio for the association between fluoroquinolone-resistant infection and mortality varied only from 1.38 to 1.65 in the 3 models.

APACHE II scores calculated at different time points relative to obtainment of the culture specimen did not differ substantively. Furthermore, when the adjusted association between fluoroquinolone resistance and mortality was assessed, there were no substantive differences across multivariable models that incorporated APACHE II scores calculated at different time points.