Although prior authorization and prospective audit with feedback are both effective antimicrobial stewardship program (ASP) strategies, the relative impact of these approaches remains unclear. We compared these core ASP strategies at an academic medical center.

Quasi-experimental study.

We compared antimicrobial use during the 24 months before and after implementation of an ASP strategy change. The ASP used prior authorization alone during the preintervention period, June 2007 through May 2009. In June 2009, many antimicrobials were unrestricted and prospective audit was implemented for cefepime, piperacillin/tazobactam, and vancomycin, marking the start of the postintervention period, July 2009 through June 2011. All adult inpatients who received more than or equal to 1 dose of an antimicrobial were included. The primary end point was antimicrobial consumption in days of therapy per 1,000 patient-days (DOT/1,000-PD). Secondary end points included length of stay (LOS).

In total, 55,336 patients were included (29,660 preintervention and 25,676 postintervention). During the preintervention period, both total systemic antimicrobial use (−9.75 DOT/1,000-PD per month) and broad-spectrum anti-gram-negative antimicrobial use (−4.00 DOT/1,000-PD) declined. After the introduction of prospective audit with feedback, however, both total antimicrobial use (+9.65 DOT/1,000-PD per month; P < .001) and broad-spectrum anti-gram-negative antimicrobial use (+4.80 DOT/1,000-PD per month; P < .001) increased significantly. Use of cefepime and piperacillin/tazobactam both significantly increased after the intervention (P = .03). Hospital LOS and LOS after first antimicrobial dose also significantly increased after the intervention (P = .016 and .004, respectively).

Significant increases in antimicrobial consumption and LOS were observed after the change in ASP strategy.

Infect Control Hosp Epidemiol 2014;35(9):1092-1099

Development of a numerical score to measure the microbial spectrum of antibiotic regimens (spectrum score) and method to identify antibiotic de-escalation events based on application of the score.

Web-based modified Delphi method.

Physician and pharmacist antimicrobial stewards practicing in the United States recruited through infectious diseases–focused listservs.

Three Delphi rounds investigated: organisms and antibiotics to include in the spectrum score, operationalization of rules for the score, and de-escalation measurement. A 4-point ordinal scale was used to score antibiotic susceptibility for organism-antibiotic domain pairs. Antibiotic regimen scores, which represented combined activity of antibiotics in a regimen across all organism domains, were used to compare antibiotic spectrum administered early (day 2) and later (day 4) in therapy. Changes in spectrum score were calculated and compared with Delphi participants’ judgments on de-escalation with 20 antibiotic regimen vignettes and with non-Delphi steward judgments on de-escalation of 300 pneumonia regimen vignettes. Method sensitivity and specificity to predict expert de-escalation status were calculated.

Twenty-four participants completed all Delphi rounds. Expert support for concepts utilized in metric development was identified. For vignettes presented in the Delphi, the sign of change in score correctly classified de-escalation in all vignettes except those involving substitution of oral antibiotics. The sensitivity and specificity of the method to identify de-escalation events as judged by non-Delphi stewards were 86.3% and 96.0%, respectively.

Identification of de-escalation events based on an algorithm that measures microbial spectrum of antibiotic regimens generally agreed with steward judgments of de-escalation status.

Infect Control Hosp Epidemiol 2014;35(9):1103-1113

To explore current practices and decision making regarding antimicrobial prescribing among emergency department (ED) clinical providers.

We conducted a survey of ED providers recruited from 8 sites in 3 cities. Using purposeful sampling, we then recruited 21 providers for in-depth interviews. Additionally, we observed 10 patient-provider interactions at one of the ED sites. SAS 9.3 was used for descriptive and predictive statistics. Interviews were audio recorded, transcribed, and analyzed using a thematic, constructivist approach with consensus coding using NVivo 10.0. Field and interview notes collected during the observational study were aligned with themes identified through individual interviews.

Of 150 survey respondents, 76% agreed or strongly agreed that antibiotics are overused in the ED, while half believed they personally did not overprescribe. Eighty-nine percent used a smartphone or tablet in the ED for antibiotic prescribing decisions. Several significant differences were found between attending and resident physicians. Interview analysis identified 42 codes aggregated into the following themes: (1) resource and environmental factors that affect care; (2) access to and quality of care received outside of the ED consult; (3) patient-provider relationships; (4) clinical inertia; and (5) local knowledge generation. The observational study revealed limited patient understanding of antibiotic use. Providers relied heavily upon diagnostics and provided limited education to patients. Most patients denied a priori expectations of being prescribed antibiotics.

Patient, provider, and healthcare system factors should be considered when designing interventions to improve antimicrobial stewardship in the ED setting.

Infect Control Hosp Epidemiol 2014;35(9):1114-1125

Patients in the neonatal intensive care unit (NICU) are at high risk for healthcare-associated infections. Variability in reported infection rates among NICUs exists, possibly related to differences in prevention strategies. A better understanding of current prevention practices may help identify prevention gaps and areas for further research.

We surveyed infection control staff in NICUs reporting to the National Healthcare Safety Network (NHSN) to assess strategies used to prevent methicillin-resistant Staphylococcus aureus (MRSA) transmission and central line–associated bloodstream infections in NICUs.

Staff from 162 of 342 NICUs responded (response rate, 47.3%). Most (92.3%) NICUs use central line insertion and maintenance bundles, but maintenance practices varied, including agents used for antisepsis and frequency of dressing changes. Forty-two percent reported routine screening for MRSA colonization upon admission for all patients. Chlorhexidine gluconate (CHG) use for central line care for at least 1 indication (central line insertion, dressing changes, or port/cap antisepsis) was reported in 82 NICUs (51.3%). Among sixty-five NICUs responding to questions on CHG use restrictions, 46.2% reported no restrictions.

Our survey illustrated heterogeneity of CLABSI and MRSA prevention practices and underscores the need for further research to define optimal strategies and evidence-based prevention recommendations for neonates.

Infect Control Hosp Epidemiol 2014;35(9):1126-1132

To determine the association between state legal mandates for data submission of central line–associated bloodstream infections (CLABSIs) in neonatal intensive care units (NICUs) with process and outcome measures.

Cross-sectional study.

Participants. National sample of level II/III and III NICUs participating in National Healthcare Safety Network (NHSN) surveillance.

State mandates for data submission of CLABSIs in NICUs in place by 2011 were compiled and verified with state healthcare-associated infection coordinators. A web-based survey of infection control departments in October 2011 assessed CLABSI prevention practices, ie, compliance with checklist/bundle components (process measures) in ICUs including NICUs. Corresponding 2011 NHSN NICU CLABSI rates (outcome measures) were used to calculate standardized infection ratios (SIRs). Association between mandates and process and outcome measures was assessed by multivariable logistic regression.

Among 190 study NICUs, 107 (56.3%) were located in states with mandates, with mandates in place >3 years in 52 (49%). More NICUs in states with mandates reported ≥95% compliance to at least 1 CLABSI prevention practice (52.3%–66.4%) than NICUs in states without mandates (28.9%–48.2%). Mandates were predictors of ≥95% compliance with all practices (odds ratio, 2.8; 95% confidence interval, 1.4–6.1). NICUs in states with mandates reported lower mean CLABSI rates in the ≤750-g birth weight group (2.4 vs 5.7 CLABSIs/1,000 central line–days) but not in others. Mandates were not associated with SIR <1.

State mandates for NICU CLABSI data submission were significantly associated with ≥95% compliance with CLABSI prevention practices, which declined with the duration of mandate but not with lower CLABSI rates.

Infect Control Hosp Epidemiol 2014;35(9):1133-1139

The current central line–associated bloodstream infection (CLABSI) surveillance rate calculation does not account for multiple concurrent central venous catheters (CVCs). The presence of multiple CVCs creates more points of entry into the bloodstream, potentially increasing CLABSI risk. Multiple CVCs may be used in sicker patients, making it difficult to separate the relative contributions of multiple CVCs and comorbidities to CLABSI risk. We explored the relative impact of multiple CVCs, patient comorbidities, and disease severity on the risk of CLABSI.

Case-control study.

A total of 197 case patients and 201 control subjects with a CVC inserted during hospitalization at a tertiary care academic medical center from January 1, 2008, to December 31, 2010.

Multiple CVCs was the exposure of interest; the primary outcome was CLABSI. Multivariable logistic regression was conducted to estimate odds ratios (ORs) and 95% confidence intervals (CIs) describing the association between CLABSI and multiple CVCs with and without controlling for Acute Physiology and Chronic Health Evaluation (APACHE) II and Charlson comorbidity index (CCI) scores as measures of disease severity and patient comorbidities, respectively.

Patients with multiple CVCs (n = 78) showed a 4.2 (95% CI, 2.2–8.4) times greater risk of CLABSI compared with patients with 1 CVC after adjusting for CLABSI risk factors. When including APACHE II and CCI scores, multiple CVCs remained an independent risk factor for CLABSI (OR, 3.4 [95% CI, 1.7–6.9]).

Multiple CVCs is an independent risk factor for CLABSI even after adjusting for severity of illness. Adjustment for this risk may be necessary to accurately compare rates between hospitals.

Infect Control Hosp Epidemiol 2014;35(9):1140-1146

To evaluate the usability and effectiveness of a computerized clinical decision support (CDS) intervention aimed at reducing the duration of urinary tract catheterizations.

Retrospective cohort study.

Academic healthcare system.

All adult patients admitted from March 2009 through May 2012.

A CDS intervention was integrated into a commercial electronic health record. Providers were prompted at order entry to specify the indication for urinary catheter insertion. On the basis of the indication chosen, providers were alerted to reassess the need for the urinary catheter if it was not removed within the recommended time. Three time periods were examined: baseline, after implementation of the first intervention (stock reminder), and after a second iteration (homegrown reminder). The primary endpoint was the usability of the intervention as measured by the proportion of reminders through which providers submitted a remove urinary catheter order. Secondary endpoints were the urinary catheter utilization ratio and the rate of hospital-acquired catheter-associated urinary tract infections (CAUTIs).

The first intervention displayed limited usability, with 2% of reminders resulting in a remove order. Usability improved to 15% with the revised reminder. The catheter utilization ratio declined over the 3 time periods (0.22, 0.20, and 0.19, respectively; P < .001), as did CAUTIs per 1,000 patient-days (0.84, 0.70, and 0.51, respectively; P < .001).

A urinary catheter removal reminder system was successfully integrated within a healthcare system’s electronic health record. The usability of the reminder was highly dependent on its user interface, with a homegrown version of the reminder resulting in higher impact than a stock reminder.

Infect Control Hosp Epidemiol 2014;35(9):1147-1155

Hand hygiene and environmental cleaning are essential infection prevention strategies, but the relative impact of each is unknown. This information is important in assessing resource allocation.

We developed an agent-based model of patient-to-patient transmission—via the hands of transiently colonized healthcare workers and incompletely terminally cleaned rooms—in a 20-patient intensive care unit. Nurses and physicians were modeled and had distinct hand hygiene compliance levels on entry and exit to patient rooms. We simulated the transmission of Acinetobacter baumannii, methicillin-resistant Staphylococcus aureus, and vancomycin-resistant enterococci for 1 year using data from the literature and observed data to inform model input parameters.

We simulated 175 parameter-based scenarios and compared the effects of hand hygiene and environmental cleaning on rates of multidrug-resistant organism acquisition. For all organisms, increases in hand hygiene compliance outperformed equal increases in thoroughness of terminal cleaning. From baseline, a 2∶1 improvement in terminal cleaning compared with hand hygiene was required to match an equal reduction in acquisition rates (eg, a 20% improvement in terminal cleaning was required to match the reduction in acquisition due to a 10% improvement in hand hygiene compliance).

Hand hygiene should remain a priority for infection control programs, but environmental cleaning can have significant benefit for hospitals or individual hospital units that have either high hand hygiene compliance levels or low terminal cleaning thoroughness.

Infect Control Hosp Epidemiol 2014;35(9):1156-1162

Hand hygiene surveillance programs that rely on direct observations of healthcare worker activity may be limited by the Hawthorne effect. In addition, comparing compliance rates from period to period requires adequately sized samples of observations. We aimed to statistically determine whether the Hawthorne effect is stable over an observation period and statistically derive sample sizes of observations necessary to compare compliance rates.

Prospective multicenter cohort study.

Five intensive care units and 6 medical/surgical wards in 3 geographically distinct acute care hospitals.

Trained observers monitored hand hygiene compliance during routine care in fixed 1-hour periods, using a standardized collection tool. We estimated the impact of the Hawthorne effect using empirical fluctuation processes and F tests for structural change. Standard sample-size calculation methods were used to estimate how many hand hygiene opportunities are required to accurately measure hand hygiene across various levels of baseline and target compliance.

Exit hand hygiene compliance increased after 14 minutes of observation (from 56.2% to 60.5%; P < .001) and increased further after 50 minutes (from 60.5% to 66.0%; P < .001). Entry compliance increased after 38 minutes (from 40.4% to 43.4%; P = .005). Between 79 and 723 opportunities are required during each period, depending on baseline compliance rates (range, 35%–90%) and targeted improvement (5% or 10%).

Limiting direct observation periods to approximately 15 minutes to minimize the Hawthorne effect and determining required number of hand hygiene opportunities observed per period on the basis of statistical power calculations would be expected to improve the validity of hand hygiene surveillance programs.

Infect Control Hosp Epidemiol 2014;35(9):1163-1168

To study a cluster of Mycobacterium wolinskyi surgical site infections (SSIs).

Observational and case-control study.

Academic hospital.

Subjects who developed SSIs with M. wolinskyi following cardiothoracic surgery.

Electronic surveillance was performed for case finding as well as electronic medical record review of infected cases. Surgical procedures were observed. Medical chart review was conducted to identify risk factors. A case-control study was performed to identify risk factors for infection; Fisher exact or Kruskal-Wallis tests were used for comparisons of proportions and medians, respectively. Patient isolates were studied using pulsed-field gel electrophoresis (PFGE). Environmental microbiologic sampling was performed in operating rooms, including high-volume water sampling.

Six definite cases of M. wolinskyi SSI following cardiothoracic surgery were identified during the outbreak period (October 1, 2008–September 30, 2011). Having cardiac surgery in operating room A was significantly associated with infection (odds ratio, 40; P = .0027). Observational investigation revealed a cold-air blaster exclusive to operating room A as well a microbially contaminated, self-contained water source used in heart-lung machines. The isolates were indistinguishable or closely related by PFGE. No environmental samples were positive for M. wolinskyi.

No single point source was established, but 2 potential sources, including a cold-air blaster and a microbially contaminated, self-contained water system used in heart-lung machines for cardiothoracic operations, were identified. Both of these potential sources were removed, and subsequent active surveillance did not reveal any further cases of M. wolinskyi SSI.

Infect Control Hosp Epidemiol 2014;35(9):1169-1175