Evaluate the evidence for effects of inpatient antimicrobial stewardship programs (ASPs) on patient, prescribing, and microbial outcomes.

Systematic review.

Search of MEDLINE (2000 through November 2013), Cochrane Library, and reference lists of relevant studies. We included English language studies with patient populations relevant to the United States (ie, infectious conditions and prescriptions required for antimicrobials) that evaluated ASP interventions and reported outcomes of interest. Study characteristics and outcomes data were extracted and reviewed by investigators and trained research personnel.

Few intervention types (eg, audit and feedback, guideline implementation, and decision support) substantially impacted patient outcomes, including mortality, length of stay, readmission, or incidence of Clostridium difficile infection. However, most interventions were not powered adequately to demonstrate impacts on patient outcomes. Most interventions were associated with improved prescribing patterns as measured by decreased antimicrobial use or increased appropriate use. Where reported, ASPs were generally associated with improvements in microbial outcomes, including institutional resistance patterns or resistance in the study population. Few data were provided on harms, sustainability, or key intervention components. Studies were typically of short duration, low in methodological quality, and varied in study design, populations enrolled, hospital setting, ASP intent, intervention composition and implementation, comparison group, and outcomes assessed.

Numerous studies suggest that ASPs can improve prescribing and microbial outcomes. Strength of evidence was low, and most studies were not designed adequately to detect improvements in mortality or other patient outcomes, but obvious adverse effects on patient outcomes were not reported.

To assess the effect of multiple sources of bias on state- and hospital-specific National Healthcare Safety Network (NHSN) laboratory-identified Clostridium difficile infection (CDI) rates.

Sensitivity analysis.

A total of 124 New York hospitals in 2010.

New York NHSN CDI events from audited hospitals were matched to New York hospital discharge billing records to obtain additional information on patient age, length of stay, and previous hospital discharges. “Corrected” hospital-onset (HO) CDI rates were calculated after (1) correcting inaccurate case reporting found during audits, (2) incorporating knowledge of laboratory results from outside hospitals, (3) excluding days when patients were not at risk from the denominator of the rates, and (4) adjusting for patient age. Data sets were simulated with each of these sources of bias reintroduced individually and combined. The simulated rates were compared with the corrected rates. Performance (ie, better, worse, or average compared with the state average) was categorized, and misclassification compared with the corrected data set was measured.

Counting days patients were not at risk in the denominator reduced the state HO rate by 45% and resulted in 8% misclassification. Age adjustment and reporting errors also shifted rates (7% and 6% misclassification, respectively).

Changing the NHSN protocol to require reporting of age-stratified patient-days and adjusting for patient-days at risk would improve comparability of rates across hospitals. Further research is needed to validate the risk-adjustment model before these data should be used as hospital performance measures.

The National Healthcare Safety Network surgical site infections risk models for hip (HPRO) and knee (KPRO) replacement are intended for case-mix adjustment when reporting surgical site infection rates across institutions, but they are not validated in external data sets

To evaluate the validity of HPRO and KPRO risk models and improvement in risk prediction with inclusion of information on morbid obesity and diabetes mellitus.

Retrospective cohort study.

A single-center cohort of 21,941 hip and knee replacement procedures performed between 2002 and 2009.

Discriminative ability was assessed using the concordance statistic (C statistic). Calibration was assessed using the Hosmer-Lemeshow goodness-of-fit tests.

The discrimination of HPRO was good, with a C statistic of 0.695 for surgical site infections and 0.749 for prosthetic joint infections. The discrimination of KPRO was worse than that of HPRO, with a C statistic of 0.592 for surgical site infections and 0.675 for prosthetic joint infections. Adding morbid obesity and diabetes mellitus to the HPRO and KPRO risk models modestly improved discrimination. There was no significant evidence of miscalibration based on the Hosmer-Lemeshow tests, but calibration of HPRO models appeared to be better than that of the KPRO models.

HPRO performed better than the KPRO in predicting surgical site infections after hip and knee replacements. Both fared well in predicting prosthetic joint infections.

Infect Control Hosp Epidemiol 2014;35(11):1323–1329

To determine whether increases in contact isolation precautions are associated with decreased adherence to isolation practices among healthcare workers (HCWs).

Prospective cohort study from February 2009 to October 2009.

Eleven teaching hospitals.

HCWs.

One thousand thirteen observations conducted on HCWs. Additional data included the number of persons in isolation, types of HCWs, and hospital-specific contact precaution practices. Main outcome measures included compliance with individual components of contact isolation precautions (hand hygiene before and after patient encounter, donning of gown and glove upon entering a patient room, and doffing upon exiting) and overall compliance (all 5 measures together) during varying burdens of isolation.

Compliance with hand hygiene was as follows: prior to donning gowns/gloves, 37.2%; gowning, 74.3%; gloving, 80.1%; doffing of gowns/gloves, 80.1%; after gown/glove removal, 61%. Compliance with all components was 28.9%. As the burden of isolation increased (20% or less to greater than 60%), a decrease in compliance with hand hygiene (43.6%—4.9%) and with all 5 components (31.5%—6.5%) was observed. In multivariable analysis, there was an increase in noncompliance with all 5 components of the contact isolation precautions bundle (odds ratio [OR], 6.6 [95% confidence interval (CI), 1.15-37.44]; P = .03) and in noncompliance with hand hygiene prior to donning gowns and gloves (OR, 10.1 [95% CI, 1.84—55.54]; P = .008) associated with increasing burden of isolation.

As the proportion of patients in contact isolation increases, compliance with contact isolation precautions decreases. Placing 40% of patients under contact precautions represents a tipping point for noncompliance with contact isolation precautions measures.

To define the relationships between age, sex and hospital-acquired infection (HAI) rates in a national cohort of hospitalized patients.

Analysis of chart-abstracted Medicare Patient Safety Monitoring System data from randomly selected medical records of patients hospitalized between January 1, 2009, and December 31, 2011, for acute cardiovascular disease, pneumonia, or major surgery associated with 1 of 6 HAIs. Patients were stratified into 6 groups. We then analyzed the association of age, sex, and 2 outcomes; the rate of occurrence of HAI for patients who were at risk and the rate of patients having at least 1 HAI.

Among 85,461 patients, all groups except younger female surgical patients had higher catheter-associated urinary tract infection (CAUTI) rates than male patients. After adjustment for comorbidities, there was no overall evidence of higher HAI rates among elderly patients. In patients with acute cardiovascular disease, women had higher rates of HAIs. Among patients with pneumonia, there was no significant difference in the rate of HAIs among most age and sex groups. Among surgical patients, all age and sex groups had a significantly higher adjusted rate of developing at least 1 HAI except females 65 years of age or older. Similar results were seen for the outcome of the occurrence rate of HAIs.

There was not an overall increased risk of HAIs among older patients hospitalized for acute cardiovascular disease, pneumonia, and major surgery after adjustment for comorbidities. The relationship between sex and the rate of HAIs varied depending upon the underlying acute reason for hospitalization.

To describe the implementation of a population-based surveillance system for multidrug-resistant gram-negative bacilli (MDR-GNB).

Population-based active surveillance by the Georgia Emerging Infections Program.

Metropolitan Atlanta, starting November 2010.

Residents with MDR-GNB isolated from urine or a normally sterile site culture.

Surveillance was implemented in 3 phases: (1) surveying laboratory antibiotic susceptibility testing practices, (2) piloting surveillance to estimate the proportion of GNB that were MDR, and (3) maintaining ongoing active surveillance for carbapenem-nonsusceptible Enterobacteriaceae and Acinetobacter baumannii using the 2010 Clinical and Laboratory Standards Institute (CLSI) breakpoints. Pilot surveillance required developing and installing queries for GNB on the 3 types of automated testing instruments (ATIs), such as MicroScan, in Atlanta's clinical laboratories. Ongoing surveillance included establishing a process to extract data from ATIs consistently, review charts, manage data, and provide feedback to laboratories.

Output from laboratory information systems typically used for surveillance would not reliably capture the CLSI breakpoints, but queries developed for the 3 ATIs did. In November 2010, 0.9% of Enterobacteriaceae isolates and 35.7% of A. baumannii isolates from 21 laboratories were carbapenem nonsusceptible. Over a 5-month period, 82 Enterobacteriaceae and 59 A. baumannii were identified as carbapenem nonsusceptible.

Directly querying ATIs, a novel method of active surveillance for MDR-GNB, proved to be a reliable, sustainable, and accurate method that required moderate initial investment and modest maintenance. Ongoing surveillance is critical to assess the burden of and changes in MDR-GNB to inform prevention efforts.

Our goal was to estimate the performance statistics of an electronic surveillance system for surgical site infections (SSIs), generally applicable in French hospitals

Three detection algorithms using 2 different data sources were tested retrospectively on 9 types of surgical procedures performed between January 2010 and December 2011 in the University Hospital of Nantes. The first algorithm was based on administrative codes, the second was based on bacteriological data, and the third used both data sources. For each algorithm, sensitivity, specificity, and positive and negative predictive values (PPV and NPV) were calculated. The reference method was the hospital’s routine surveillance: a comprehensive review of the computerized medical charts of the patients who underwent one of the targeted procedures during the study period.

A 3,000-bed teaching hospital in western France.

We analyzed 4,400 targeted surgical procedures.

Sensitivity results varied significantly between the three algorithms, from 25% (95% confidence interval, 17–33) when using only administrative codes to 87% (80%–93%) with the bacteriological data and 90% (85%–96%) with the combined algorithm. Fewer variations were observed for specificity (91%–98%), PPV (21%–25%), and NPV (98% to nearly 100%). Overall, performance statistics were higher for deep SSIs than for superficial infections.

A reliable computer-enhanced SSI surveillance can easily be implemented in French hospitals using common data sources. This should allow infection control professionals to spend more time on prevention and education duties. However, a multicenter study should be conducted to assess the generalizability of this method.

Infect Control Hosp Epidemiol 2014;35(11):1330–1335

Our aim was to evaluate the impact of aerators on water microbiological contamination in at-risk hospital departments, with a view to quantifying the possible risk of patient exposure to waterborne microorganisms.

We analyzed the microbiological and chemical-physical characteristics of hot and cold water in some critical hospital departments.

Two hospitals in northern Italy.

We took 304 water samples over a 1-year period, at 3-month intervals, from taps used by healthcare personnel for handwashing, surgical washing, and the washing of medical equipment. We analyzed heterotrophic plate counts (HPCs) at 36°C and 22°C, nonfastidious gram-negative bacteria (GNB-NE), and Legionella pneumophila.

The percentages of positivity and mean values of HPCs at 22°C, HPCs at 36°C, and GNB-NE loads were significantly higher at outlet points than in the plumbing system. In particular, GNB-NE positivity was higher at outlet points than in the plumbing system in both the cold water (31.58% vs 6.58% of samples were positive) and hot water (21.05% vs 3.95%) supplies. Our results also revealed contamination by L. pneumophila both in the plumbing system and at outlet points, with percentages of positive samples varying according to the serogroup examined (serogroups 1 and 2-14). The mean concentrations displayed statistically significant (P < .001) differences between the outlet points (27,382.89 ± 42,245.33 colony-forming units [cfu]/L) and the plumbing system (19,461.84 ± 29,982.11 cfu/L).

These results reveal a high level of contamination of aerators by various species of gram-negative opportunists that are potentially very dangerous for immunocompromised patients and, therefore, the need to improve the management of these devices.