To examine the effect of heterogeneous case mix for a benchmarking analysis and interhospital comparison of the prevalence rates of nosocomial infection.

Cross-sectional survey.

Eleven hospitals located in Cyprus and in the region of Crete in Greece.

The survey included all inpatients in the medical, surgical, pediatric, and gynecology-obstetrics wards, as well as those in intensive care units. Centers for Disease Control and Prevention criteria were used to define nosocomial infection. The information collected for all patients included demographic characteristics, primary admission diagnosis, Karnofsky functional status index, Charlson comorbidity index, McCabe- Jackson severity of illness classification, use of antibiotics, and prior exposures to medical and surgical risk factors. Outcome data were also recorded for all patients. Case mix-adjusted rates were calculated by using a multivariate logistic regression model for nosocomial infection risk and an indirect standardization method.

The overall prevalence rate of nosocomial infection was 7.0% (95% confidence interval, 5.9%–8.3%) among 1,832 screened patients. Significant variation in nosocomial infection rates was observed across hospitals (range, 2.2%–9.6%). Logistic regression analysis indicated that the mean predicted risk of nosocomial infection across hospitals ranged from 3.7% to 10.3%, suggesting considerable variation in patient risk. Case mix-adjusted rates ranged from 2.6% to 12.4%, and the relative ranking of hospitals was affected by case-mix adjustment in 8 cases (72.8%). Nosocomial infection was significantly and independently associated with mortality (adjusted odds ratio, 3.6 [95% confidence interval, 2.1–6.1]).

The first attempt to rank the risk of nosocomial infection in these regions demonstrated the importance of accounting for heterogeneous case mix before attempting interhospital comparisons.

Standing order programs (SOPs), which allow for vaccination without an individual physician order, are the most effective mechanism to achieve high vaccination rates. Among the suggested settings for the utilization of SOPs are hospital inpatient units, because they provide care for those most likely to benefit from vaccination. The cost-effectiveness of this approach for elderly hospitalized persons is unknown. The purpose of this study was to estimate the cost-effectiveness of SOPs for pneumococcal polysaccharide vaccine (PPV) vaccination for patients 65 years of age or older in 2 types of hospital.

In 2004, a 1,094-bed tertiary care hospital implemented a pharmacy-based SOP for PPV, and a 225-bed community hospital implemented a nursing-based SOP for PPV. Newly admitted patients 65 years of age or older were screened for PPV eligibility and then offered PPV. Vaccination rates before and after initiation of SOPs in the United States, incidence rates of invasive pneumococcal disease in the United States, and US economic data were the bases of the cost-effectiveness analyses. One-way and multivariate sensitivity analyses were conducted.

PPV vaccination rates increased 30.5% in the tertiary care hospital and 15.3% in the community hospital. In the base-case cost-effectiveness analysis, using a societal perspective, we found that both pharmacy-based and nursing-based SOPs cost less than $10,000 per quality-adjusted life-year gained, with program costs (pharmacy-based SOPs cost $4.16 per patient screened, and nursing-based SOPs cost $4.60 per patient screened) and vaccine costs ($18.33 per dose) partially offset by potential savings from cases of invasive pneumococcal disease avoided ($12,436 per case). Sensitivity analyses showed SOPs for PPV vaccination to be cost-effective, compared with PPV vaccination without SOPs, unless the improvement in vaccination rate was less than 8%.

SOPs do increase PPV vaccination rates in hospitalized elderly patients and are economically favorable, compared with PPV vaccination rates without SOPs.

To determine the timing of community-onset Clostridium difficile–associated disease (CDAD) relative to the patient's last healthcare facility discharge, the association of postdischarge cases with healthcare facility–onset cases, and the influence of postdischarge cases on overall rates and interhospital comparison of rates of CDAD.

Retrospective cohort study for the period January 1, 2005, through December 31, 2005.

Catchment areas of 6 acute care hospitals in North Carolina.

We reviewed medical and laboratory records to determine the date of symptom onset, the dates of hospitalization, and stool C. difficile toxin assay results for patients with CDAD who had diarrhea and positive toxin–assay results. Cases were classified as healthcare facility–onset if they were diagnosed more than 48 hours after admission. Cases were defined as community-onset if they were diagnosed in the community or within 48 hours after admission, and were also classified on the basis of the time since the last discharge: if within 4 weeks, community-onset, healthcare facility–associated (CO-HCFA); if 4-12 weeks, indeterminate exposure; and if more than 12 weeks, community-associated. Pearson's correlation coefficient was used to assess the association between monthly rates of healthcare facility–onset, healthcare facility–associated (HO-HCFA) cases and CO-HCFA cases. We performed interhospital rate comparisons using HO-HCFA cases only and using both HO-HCFA and CO-HCFA cases.

Of 1046 CDAD cases, 442 (42%) were HO-HCFA cases and 604 (58%) were community-onset cases. Of the 604 community-onset cases, 94 (15%) were CO-HCFA, 40 (7%) were of indeterminate exposure, and 208 (34%) community-associated. A modest correlation was found between monthly rates of HO-HCFA cases and CO-HCFA cases across the 6 hospitals (r = 0.63, P<.001). Interhospital rankings changed for 6 of 11 months if CO-HCFA cases were included.

A substantial proportion of community-onset cases of CDAD occur less than 4 weeks after discharge from a healthcare facility, and inclusion of CO-HCFA cases influences interhospital comparisons. Our findings support the use of a proposed definition of healthcare facility–associated CDAD that includes cases that occur within 4 weeks after discharge.

To evaluate the receipt of information and knowledge about influenza and vaccination, as well as influenza vaccination status and reasons for declining vaccination, among registered nurses.

Cross-sectional survey of registered nurses (RNs).

A large tertiary medical center with a long-standing, multifaceted influenza vaccination program and relatively high vaccination rates among employees overall (76.5%).

Randomly selected group of 990 RNs employed as inpatient staff nurses at the institution.

The survey was completed by 513 (51.8%) of 990 RNs. Most RNs (86.7%) had received an influenza vaccination in the past, and 331 (64.5%) intended to receive vaccination during the 2005-2006 influenza season. More than 90% of RNs acknowledged exposure to educational bulletins, and most had received information about influenza severity (383 [74.7%]), transmission (398 [77.6%]), vaccine safety (416 [81.1%]), and the time and location of free vaccination (460 [89.7%]). A majority (436 [85.0%]) felt they had received all the information they needed to make good decisions about vaccination. However, only 49 RNs (9.6%) gave correct answers to more than 85% of the knowledge questions on the survey. The reasons most frequently reported for declining vaccination were doubts about the risk of influenza and the need for vaccination, concerns about vaccine effectiveness and side effects, and dislike of injections.

RNs exposed to a longstanding, multifaceted educational program had received information about influenza vaccination, but misconceptions were common and only 331 (64.5%) intended to receive vaccination. Strategies other than educational interventions are needed to increase influenza vaccination rates and thereby to ensure healthcare worker and patient safety.

A hospital discovered a lapse in the reprocessing procedures for transrectal ultrasound-guided prostate biopsy equipment. An investigation was initiated to assess the risks of transmission of hepatitis B virus (HBV), hepatitis C virus (HCV), human immunodeficiency virus (HIV), and bacteria during prostate biopsies.

We offered testing for HBV, HCV, and HIV infection to patients who had undergone prostate biopsies from January 30, 2003, through January 27, 2006. We reviewed their medical records and obtained information on the reprocessing procedures that were in use at the time for the prostate biopsy equipment.

A healthcare facility in Maine.

Of the 528 patients exposed to improperly reprocessed prostate biopsy equipment, none tested positive for HIV or HCV. Sixteen patients (3%) tested positive for past HBV infection but had no prebiopsy HBV serologic test results available (ie, transmission from improperly reprocessed biopsy equipment was possible), and 11 (2%) had evidence of postbiopsy bacterial infections. The number of cases of HBV and bacterial infections were within reported ranges for this population and were not clustered in time. Review of the reprocessing procedures in use at the time revealed that the manufacturer-recommended brushes for cleaning the reusable biopsy needle guide were never used. Brushes did not come with the equipment and had to be ordered separately.

Despite the lack of evidence of pathogen transmission in this investigation, it is critical to review the manufacturer's reprocessing recommendations and to establish appropriate procedures to avert potential pathogen transmission and subsequent patient concerns. This investigation provides a better understanding of the risks associated with improperly reprocessed transrectal ultrasound prostate biopsy equipment and serves as a methodologic tool for future investigations.

Carbapenem-resistant Klebsiella pneumoniae is an emerging healthcare-associated pathogen.

To describe the epidemiology of and clinical outcomes associated with carbapenem-resistant K. pneumoniae infection and to identify risk factors associated with mortality among patients with this type of infection.

Mount Sinai Hospital, a 1,171-bed tertiary care teaching hospital in New York City.

Two matched case-control studies.

In the first matched case-control study, case patients with carbapenem-resistant K. pneumoniae infection were compared with control patients with carbapenem-susceptible K. pneumoniae infection. In the second case-control study, patients who survived carbapenem-resistant K. pneumoniae infection were compared with those who did not survive, to identify risk factors associated with mortality among patients with carbapenem-resistant K. pneumoniae infection.

There were 99 case patients and 99 control patients identified. Carbapenem-resistant K. pneumoniae infection was independently associated with recent organ or stem-cell transplantation (P = .008), receipt of mechanical ventilation (P = .04), longer length of stay before infection (P = .01), and exposure to cephalosporins (P = .02) and carbapenems (P < .001). Case patients were more likely than control patients to die during hospitalization (48% vs 20%; P < .001) and to die from infection (38% vs 12%; P < .001). Removal of the focus of infection (ie, debridement) was independently associated with patient survival (P = .002). The timely administration of antibiotics with in vitro activity against carbapenem-resistant K. pneumoniae was not associated with patient survival.

Carbapenem-resistant K. pneumoniae infection is associated with numerous healthcare-related risk factors and with high mortality. The mortality rate associated with carbapenem-resistant K. pneumoniae infection and the limited antimicrobial options for treatment of carbapenem-resistant K. pneumoniae infection highlight the need for improved detection of carbapenem-resistant K. pneumoniae infection, identification of effective preventive measures, and development of novel agents with reliable clinical efficacy against carbapenem-resistant K. pneumoniae.

Independent risk factors for surgical site infection (SSI) after cesarean section have not been well documented, despite the large number of cesarean sections performed and the relatively common occurrence of SSI.

To determine independent risk factors for SSI after low transverse cesarean section.

Retrospective case-control study.

Barnes-Jewish Hospital, a 1,250-bed tertiary care hospital.

A total of 1,605 women who underwent low transverse cesarean section during the period from July 1999 to June 2001.

Using the International Classification of Diseases, Ninth Revision, Clinical Modification diagnosis codes for SSI or wound complication and/or data on antibiotic use during the surgical hospitalization or at readmission to the hospital or emergency department, we identified potential cases of SSI in a cohort of patients who underwent a low transverse cesarean section. Cases of SSI were verified by chart review using the definitions from the Centers for Disease Control and Prevention's National Nosocomial Infections Surveillance System. Control patients without SSI or endomyometritis were randomly selected from the population of patients who underwent cesarean section. Independent risk factors for SSI were determined by logistic regression.

SSIs were identified in 81 (5.0%) of 1,605 women who underwent low transverse cesarean section. Independent risk factors for SSI included development of subcutaneous hematoma after the procedure (adjusted odds ratio [aOR], 11.6 [95% confidence interval {CI}, 4.1–33.2]), operation performed by the university teaching service (aOR, 2.7 [95% CI, 1.4–5.2]), and a higher body mass index at admission (aOR, 1.1 [95% CI, 1.0–1.1]). Cephalosporin therapy before or after the operation was associated with a significantly lower risk of SSI (aOR, 0.2 [95% CI, 0.1–0.5]). Use of staples for skin closure was associated with a marginally increased risk of SSI.

These independent risk factors should be incorporated into approaches for the prevention and surveillance of SSI after surgery.

To assess the rate of and the risk factors for the detection of methicillin-resistant S. aureus (MRSA) and vancomycin-resistant enterococci (VRE) on the protective gowns and gloves of healthcare workers (HCWs).

We observed the interactions between HCWs and patients during routine clinical activities in a 29-bed medical intensive care unit at the University of Maryland Medical Center, an urban tertiary care academic hospital. Samples for culture were obtained from HCWs' hands prior to their entering a patient's room, from HCWs' disposable gowns and gloves after they completed patient care activities, and from HCWs' hands immediately after they removed their protective gowns and gloves.

Of 137 HCWs caring for patients colonized or infected with MRSA and/or VRE, 24 (17.5%; 95% confidence interval, 11.6%–24.4%) acquired the organism on their gloves, gown, or both. HCW contact with the endotracheal tube or tracheostomy site of a patient (P < .05), HCW contact with the head and/or neck of a patient (P < .05), and HCW presence in the room of a patient with a percutaneous endoscopic gastrostomy and/or jejunostomy tube (P < .05) were associated with an increased risk of acquiring these organisms.

The gloves and gowns of HCWs frequently become contaminated with MRSA and VRE during the routine care of patients, and particularly during care of the patient's respiratory tract and any associated indwelling devices. As part of a larger infection control strategy, including high-compliance hand disinfection, they likely provide a useful barrier to transmitting antibiotic-resistant organisms among patients in an inpatient setting.

The quality of environmental hygiene in hospitals is under increasing scrutiny from both healthcare providers and consumers because the prevalence of serious infections due to multidrug-resistant pathogens has reached alarming levels. On the basis of the results from a small number of hospitals, we undertook a study to evaluate the thoroughness of disinfection and cleaning in the patient's immediate environment and to identify opportunities for improvement in a diverse group of acute care hospitals.

Prospective multicenter study to evaluate the thoroughness of terminal room cleaning in hospitals using a novel targeting method to mimic the surface contamination of objects in the patient's immediate environment.

Twenty-three acute care hospitals.

The overall thoroughness of terminal cleaning, expressed as a percentage of surfaces evaluated, was 49% (range for all 23 hospitals, 35%-81%). Despite the tight clustering of overall cleaning rates in 21 of the hospitals, there was marked variation within object categories, which was particularly notable with respect to the cleaning of toilet handholds, bedpan cleaners, light switches, and door knobs (mean cleaning rates, less than 30%; institutional ranges, 0%-90%). Sinks, toilet seats, and tray tables, in contrast, were consistently relatively well cleaned (mean cleaning rates, over 75%). Patient telephones, nurse call devices, and bedside rails were inconsistently cleaned.

We identified significant opportunities in all participating hospitals to improve the cleaning of frequently touched objects in the patient's immediate environment. The information obtained from such assessments can be used to develop focused administrative and educational interventions that incorporate ongoing feedback to the environmental services staff, to improve cleaning and disinfection practices in healthcare institutions.

To compare and contrast the epidemiology of polymicrobial and monomicrobial bloodstream infections (BSIs) in newborn intensive care unit (NICU) patients.

Retrospective, matched case-control study.

The Yale-New Haven Hospital NICU from 1989 through 2006.

NICU patients with BSIs.

Each neonate with polymicrobial BSI (case patient) was matched to one neonate with monomicrobial BSI (control patient), by birth date, weight, and sex; and univariate and multivariate analyses were performed.

One hundred five cases of polymicrobial BSI were identified in 102 infants, representing 10% of all neonatal BSIs in our institution. Coagulase-negative staphylococci were the most common organisms recovered from culture. Infants with polymicrobial BSI had later onset of infection than infants with monomicrobial BSI (mean day of life, 37.5 vs 24.0; P< .001). Polymicrobial BSI occurred more frequently among infants with a severe underlying condition than in those without such a condition (odds ratio [OR], 1.8; 95% confidence interval [CI], 1.1-3.2) and among infants requiring an indwelling central venous catheter for a prolonged duration (mean, 16.9 days, compared with 9.8 days for infants with monomicrobial BSI; P = .001). Multivariate analysis revealed that later onset of infection (adjusted OR [aOR], 1.02; 95% CI, 1.00-1.04) and presence of a severe underlying condition (aOR, 1.91; 95% CI, 1.12-3.38) were independent risk factors for polymicrobial BSI. No differences in outcome or mortality were observed.

Changes in the microbiology and epidemiology of NICU-related polymicrobial BSI have occurred since the last North American review. In the present study, although differences were observed, most risk factors and outcomes were similar between monomicrobial BSI and polymicrobial BSI. Epidemiologic surveillance is critical to identify trends associated with neonatal polymicrobial BSI, particularly those that may impact preventative strategies, diagnostic measures, and therapeutic interventions.

There are limited data from prospective studies to indicate whether improvement in hand hygiene associated with the use of alcohol-based hand hygiene products results in improved patient outcomes.

A 2-year, prospective, controlled, cross-over trial of alcohol-based hand gel.

The study was conducted in 2 medical-surgical ICUs for adults, each with 12 beds, from August 2001 to September 2003 at a university-associated, tertiary care teaching hospital.

An alcohol-based hand gel was provided in one critical care unit and not provided in the other. After 1 year, the assignment was reversed. The hand hygiene adherence rate and the incidence of nosocomial infection were monitored. Samples for culture were obtained from nurses' hands every 2 months.

During 17,994 minutes of observation, which included 3,678 opportunities for hand hygiene, adherence rates improved dramatically after the introduction of hand gel, increasing from 37% to 68% in one unit and from 38% to 69% in the other unit (P < .001). Improvement was observed among all groups of healthcare workers. Hand hygiene rates were better at higher workloads when hand gel was available in the unit (P = .02). No substantial change in the rates of device-associated infection, infection due to multidrug-resistant pathogens, or infection due to Clostridium difficile was observed. Culture of samples from the hands of nursing staff revealed that an increased number of microbes and an increased number of microbe species was associated with longer fingernails (ie, more than 2 mm long), the wearing of rings, and/or lack of access to hand gel.

The introduction of alcohol-based gel resulted in a significant and sustained improvement in the rate of hand hygiene adherence. Fingernail length greater than 2 mm, wearing rings, and lack of access to hand gel were associated with increased microbial carriage on the hands. This improvement in the hand hygiene adherence rate was not associated with detectable changes in the incidence of healthcare-associated infection.

To describe variability in rates of antibacterial use in a large sample of US hospitals and to create risk-adjusted models for interhospital comparison.

We retrospectively surveyed the use of 87 antibacterial agents on the basis of electronic claims data from 130 medical-surgical hospitals in the United States for the period August 2002 to July 2003; these records represented 1,798,084 adult inpatients. Hospitals were assigned randomly to the derivation data set (65 hospitals) or the validation data set (65 hospitals). Multivariable models predicting rates of antibacterial use were created using the derivation data set. These models were then used to predict rates of antibacterial use in the validation data set, which was compared with observed rates of antibacterial use. Rates of antibacterial use was measured in days of therapy per 1,000 patient-days.

Across the surveyed hospitals, a mean of 59.3% of patients received at least 1 dose of an antimicrobial agent during hospitalization (range for individual hospitals, 44.4%-73.6%). The mean total rate of antibacterial use was 789.8 days of therapy per 1,000 patient-days (range, 454.4-1,153.4). The best model for the total rate of antibacterial use explained 31% of the variance in rates of antibacterial use and included the number of hospital beds, the number of days in the intensive care unit per 1,000 patient-days, the number of surgeries per 1,000 discharges, and the number of cases of pneumonia, bacteremia, and urinary tract infection per 1,000 discharges. Five hospitals in the validation data set were identified as having outlier rates on the basis of observed antibacterial use greater than the upper bound of the 90% prediction interval for predicted antibacterial use in that hospital.

Most adult inpatients receive antimicrobial agents during their hospitalization, but there is substantial variability between hospitals in the volume of antibacterials used. Risk-adjusted models can explain a significant proportion of this variation and allow for comparisons between hospitals for benchmarking purposes.

To describe the frequency of selected antimicrobial resistance patterns among pathogens causing device-associated and procedure-associated healthcare-associated infections (HAIs) reported by hospitals in the National Healthcare Safety Network (NHSN).

Data are included on HAIs (ie, central line-associated bloodstream infections, catheter-associated urinary tract infections, ventilator-associated pneumonia, and surgical site infections) reported to the Patient Safety Component of the NHSN between January 2006 and October 2007. The results of antimicrobial susceptibility testing of up to 3 pathogenic isolates per HAI by a hospital were evaluated to define antimicrobial-resistance in the pathogenic isolates. The pooled mean proportions of pathogenic isolates interpreted as resistant to selected antimicrobial agents were calculated by type of HAI and overall. The incidence rates of specific device-associated infections were calculated for selected antimicrobial-resistant pathogens according to type of patient care area; the variability in the reported rates is described.

Overall, 463 hospitals reported 1 or more HAIs: 412 (89%) were general acute care hospitals, and 309 (67%) had 200-1,000 beds. There were 28,502 HAIs reported among 25,384 patients. The 10 most common pathogens (accounting for 84% of any HAIs) were coagulase-negative staphylococci (15%), Staphylococcus aureus (15%), Enterococcus species (12%), Candida species (11%), Escherichia coli (10%), Pseudomonas aeruginosa (8%), Klebsiella pneumoniae (6%), Enterobacter species (5%), Acinetobacter baumannii (3%), and Klebsiella oxytoca (2%). The pooled mean proportion of pathogenic isolates resistant to antimicrobial agents varied significantly across types of HAI for some pathogen-antimicrobial combinations. As many as 16% of all HAIs were associated with the following multidrug-resistant pathogens: methicillin-resistant S. aureus (8% of HAIs), vancomycin-resistant Enterococcus faecium (4%), carbapenem-resistant P. aeruginosa (2%), extended-spectrum cephalosporin-resistant K. pneumoniae (1%), extended-spectrum cephalosporin-resistant E. coli (0.5%), and carbapenem-resistant A. baumannii, K. pneumoniae, K. oxytoca, and E. coli (0.5%). Nationwide, the majority of units reported no HAIs due to these antimicrobial-resistant pathogens.