Mortality attributable to hospital acquired infections with multidrug-resistant bacteria in a large group of German hospitals.

BACKGROUND: According to extrapolations, around 35,000 patients in Germany develop hospital acquired infections (HAI) with a multidrug-resistant organism (MDRO) every year, and about 1500 of them die. Previous estimations were based on laboratory data and prevalence studies. Aim of this study was to establish the incidences of hospital acquired MDRO infections and the resulting deaths by expert review. METHODS: Data on patients suffering from a hospital acquired MDRO infection were collected from 32 hospitals from all care levels. Records of patients with MDRO infection who died in the year 2016 underwent an onsite review by two experts to determine the impact of the infection, if any, on the cause of death. RESULTS: A total of 714,108 in-patients were treated in 32 hospitals participating in the study. Of these patients, 1136 suffered a hospital acquired MDRO infection (1.59 per 1000 patients). 215 patients with an MDRO infection died [0.301 per 1000, (95% CI 0,261-0,341)], but only in 78 cases this was estimated as the cause of death [0.109 per 1000 patients (95% CI 0.085-0.133)]. CONCLUSION: By putting the above rates in relation to the total number of in-patients in Germany, it can be rated that around 31,052 patients per year suffer a hospital acquired MDRO infection, and 2132 patients die from it. These results from our reviewer investigation confirm earlier extrapolations.

Representativeness of the surveillance data in the intensive care unit component of the German nosocomial infections surveillance system.

OBJECTIVE: To assess the representativeness of the data in the Krankenhaus Infektions Surveillance System (KISS), which is a nosocomial infections surveillance system for intensive care units (ICUs) in Germany. DESIGN: Prospective and retrospective surveillance study. SETTING: Medical-surgical ICUs in Germany. METHODS: A sample of medical-surgical ICUs from all over Germany, stratified according to hospital size, was randomly selected. Surveillance personnel from the hospitals were trained in surveillance of nosocomial infections, and they subsequently conducted a 2-month surveillance in their ICUs. Data were compared with KISS data for medical-surgical ICUs. RESULTS: During the period from 2004 through 2005, a total of 50 medical-surgical ICUs agreed to participate in our study: 21,832 patient-days were surveyed, and 262 cases of nosocomial infection were registered, 176 of which were cases of device-associated nosocomial infection (100 cases of lower respiratory tract infection, 47 cases of urinary tract infection, and 29 cases of bloodstream infection). The overall incidence density of all types of nosocomial infections was estimated to be 10.65 cases per 1,000 patient-days. Device utilization rates in the study ICUs and in the KISS medical-surgical ICUs were similar. The pooled mean device-associated infection rates were higher in the study ICUs than in the KISS medical-surgical ICUs (10.2 vs 5.1 cases of pneumonia; 2.0 vs 1.2 cases of bloodstream infection; and 2.7 vs 1.2 cases of urinary tract infection), but the pooled mean device-associated infection rates in the study ICUs were comparable to those of the KISS ICUs during their first year of participation in KISS. The incidence density for nosocomial infections in the study ICUs varied according hospital size, with ICUs in larger hospitals having a higher incidence density than those in smaller hospitals. CONCLUSIONS: KISS ICUs started with nosocomial infection rates comparable to those found in our study ICUs. Over the years of participation, however, a decrease in nosocomial infections is seen. Thus, rates of nosocomial infection from KISS should be used as benchmarks, but estimations for Germany that are based on KISS data may underestimate the real burden of nosocomial infections.

Use of central venous catheter and peripheral venous catheter as risk factors for nosocomial bloodstream infection in very-low-birth-weight infants.

OBJECTIVE: To describe the relationship between the use of central and peripheral venous catheters and the risk of nosocomial, primary, laboratory-confirmed bloodstream infection (BSI) for neonates with a birth weight less than 1,500 g (very-low-birth-weight [VLBW] infants). METHODS: Cox proportional hazard regression analysis with time-dependent variable was used to determine the risk factors for the occurrence of BSI in a cohort of VLBW infants. We analyzed previously collected surveillance data from the German national nosocomial surveillance system for VLBW infants. All VLBW infants in 22 participating neonatal departments who had a complete daily record of patient information were included. RESULTS: Of 2,126 VLBW infants, 261 (12.3%) developed a BSI. The incidence density for BSI was 3.3 per 1,000 patient-days. The multivariate analysis identified the following significant independent risk factors for BSI: lower birth weight (hazard ratio [HR], 1.1-2.2), vaginal delivery (HR, 1.5), central venous catheter use (HR, 6.2) or peripheral venous catheter use (HR, 6.0) within 2 days before developing BSI, and the individual departments (HR, 0.0-4.6). CONCLUSIONS: After adjusting for other risk factors, use of peripheral venous catheter and use of central venous catheter were significantly related to occurrence of BSI in VLBW infants.

Is there an association between nosocomial infection rates and bacterial cross transmissions?

OBJECTIVE: Surveillance data of nosocomial infection rates are increasingly used for public reporting and interhospital comparisons. Approximately 15% of nosocomial infections on intensive care units are the result of patient-to-patient transmissions of the causative organisms. These exogenous infections could be prevented by adherence to basic infection control measures. The association between bacterial cross transmissions and nosocomial infection rates was analyzed. DESIGN: Prospective cohort study during 24 months. SETTING: Eleven intensive care units from two university hospitals. PATIENTS: All inpatients. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Primary isolates of six indicator organisms (Acinetobacter baumannii, Enterococcus faecalis and E. faecium, Klebsiella pneumoniae, Pseudomonas aeruginosa, Staphylococcus aureus) cultured from clinical samples or methicillin-resistant S. aureus surveillance testing of all inpatients were genotyped. Indistinguishable isolates in > or =2 patients defined potential episodes of transmissions. Surveillance of nosocomial infection rates was performed according to the German nosocomial infection surveillance system, Krankenhaus Infektions Surveillance System. Transmission events and nosocomial infection rates were pooled by intensive care unit to calculate Spearman's rank-correlation test. During 100,781 patient days, 100,829 microbiological specimens from 24,362 patients were sampled (average investigation density: 1.0 sample per patient and day) and 3419 primary indicator organisms were cultured. Altogether, 462 transmissions (incidence density of 4.6 transmissions per 1000 patient days; range, 1.4-8.4 days) and 1216 nosocomial infections (incidence density of 12.1 per 1000 patient days; range, 6.2-16.6 days) were discerned. Correlation analysis was unable to reveal any association between the incidence of cross transmissions and nosocomial infections, duration of hospitalization, or device use. CONCLUSIONS: Differences in nosocomial infection rates between study intensive care units are not explained solely by cross transmissions. Other factors, like the severity of the patient's underlying diseases, the patient's endogenous flora, or invasive procedures, likely have a dominant effect on the magnitude of nosocomial infection rates.

Outbreak of carbapenem-resistant Acinetobacter baumannii carrying the carbapenemase OXA-23 in a German university medical centre.

A prolonged outbreak of carbapenem-resistant Acinetobacter baumannii in a German university medical centre in 2006 was investigated; the investigation included a descriptive epidemiological analysis, a case-control study, environmental sampling, molecular typing of A. baumannii isolates using PFGE and repetitive-sequence-based PCR (rep-PCR) typing, and detection of OXA-type carbapenemases by multiplex PCR. Thirty-two patients acquired the outbreak strain in five intensive care units (ICUs) and two regular wards at a tertiary care hospital within 10 months. The outbreak strain was resistant to penicillins, cephalosporins, ciprofloxacin, gentamicin, tobramycin, imipenem and meropenem, and carried the bla(OXA-23)-like gene. Based on PFGE and rep-PCR typing, it was shown to be related to the pan-European A. baumannii clone II. The most likely mode of transmission was cross-transmission from colonized or infected patients via the hands of health-care workers, with the severity of disease and intensity of care (therapeutic intervention scoring system 28 score >median) being independently associated with acquisition of the outbreak strain (odds ratio 6.67, 95 % confidence interval 1.55-36.56). Control of the outbreak was achieved by enforcement of standard precautions, education of personnel, screening of ICU patients for carbapenem-resistant A. baumannii and cohorting of patients. This is believed to be the first report of an outbreak of A. baumannii carrying the carbapenemase OXA-23 in Germany.

Early- and late-onset pneumonia: is this still a useful classification?

The choice of empirical treatment of nosocomial pneumonia in the intensive-care unit (ICU) used to rely on the interval after the start of mechanical ventilation. Nowadays, however, the question of whether in fact there is a difference in the distribution of causative pathogens is under debate. Data from 308 ICUs from the German National Nosocomial Infection Surveillance System, including information on relevant pathogens isolated in 11,285 cases of nosocomial pneumonia from 1997 to 2004, were used for our evaluation. Each individual pneumonia case was allocated either to early- or to late-onset pneumonia, with three differentiation criteria: onset on the 4th day, the 5th day, or the 7th day in the ICU. The frequency of pathogens was evaluated according to these categories. A total of 5,066 additional cases of pneumonia were reported from 2005 to 2006, after the CDC criteria had been modified. From 1997 to 2004, the most frequent microorganisms were Staphylococcus aureus (2,718 cases, including 720 with methicillin [meticillin]-resistant S. aureus), followed by Pseudomonas aeruginosa (1,837 cases), Klebsiella pneumoniae (1,305 cases), Escherichia coli (1,137 cases), Enterobacter spp. (937 cases), streptococci (671 cases), Haemophilus influenzae (509 cases), Acinetobacter spp. (493 cases), and Stenotrophomonas maltophilia (308 cases). The order of the four most frequent pathogens (accounting for 53.7% of all pathogens) was the same in both groups and was independent of the cutoff categories applied: S. aureus was first, followed by P. aeruginosa, K. pneumoniae, and E. coli. Thus, the predictabilities of the occurrence of pathogens were similar for the earlier (1997-to-2004) and later (2005-to-2006) time frames. This classification is no longer helpful for empirical antibiotic therapy, since the pathogens are the same for both groups.

Ten years of KISS: the most important requirements for success.

Ten years ago, in January 1997, data collection for the German national nosocomial infection surveillance system was established, which is known by the acronym KISS (Krankenhaus-Infektions-Surveillance-System). Meanwhile KISS was able to demonstrate a beneficial effect from ongoing surveillance activities and appropriate feedback to the users in combination with reference data for ventilator associated pneumonia, primary bloodstream infections and surgical site infections. Significant reductions of infection rates between 20-30% over 3 years periods in the components for intensive care units, operative departments and neonatal intensive care units were demonstrated. Due to our experience the following requirements have to be fulfilled to keep a surveillance system successful over longer periods: close contact between the participating institutions, consideration of new developments, timely regular data feedback and constant reevaluation of the way of data presentation, data validity and demonstration of its contribution to the reduction of healthcare associated infections (HAI). The article describes in more detail how KISS tries to fulfill these requirements.

Operating room ventilation with laminar airflow shows no protective effect on the surgical site infection rate in orthopedic and abdominal surgery.

OBJECTIVE: To evaluate whether operating room (OR) ventilation with (vertical) laminar airflow impacts on surgical site infection (SSI) rates. DESIGN: Retrospective cohort-study based on routine surveillance data. PATIENTS AND METHODS: Sixty-three surgical departments participating voluntarily in the German national nosocomial infections surveillance system "KISS" were included (a total of 99,230 operations). Active SSI surveillance was performed according to the methods and definitions given by the US National Nosocomial Infection Surveillance system. Surgical departments were stratified according to type of OR ventilation used: (1) turbulent ventilation with high-efficiency particulate air-filtered air, and (2) HEPA-filtered (vertical) laminar airflow ventilation. Multivariate analyses were performed by the generalized estimating equations method to control for the following variables as possible confounders: (a) Patient-based: wound contamination class, ASA score, operation duration, patients' age and gender, endoscopic operation; (b) Hospital-based: the number of beds in the hospital, its academic status, operation frequency, and long-term participation in KISS. RESULTS: The risk for severe SSI after hip prosthesis implantation was significantly higher using laminar airflow OR ventilation (1.63 < 1.06; 2.52>), as compared with turbulent ventilation. The adjusted odds ratios for the other operative procedures analyzed were: knee prosthesis 1.76 < 0.80, 3.85>; appendectomy 1.52 < 0.91, 2.53>; cholecystectomy 1.37 < 0.63, 2.97>; colon surgery 0.85 < 0.49, 1.49>; and herniorrhaphy 1.48 < 0.67; 3.25>. CONCLUSIONS: Unexpectedly, in this analysis, which controlled for many patient and hospital-based confounders, OR ventilation with laminar airflow showed no benefit and was even associated with a significantly higher risk for severe SSI after hip prosthesis.

Risk factors for the development of nosocomial pneumonia and mortality on intensive care units: application of competing risks models.

INTRODUCTION: Pneumonia is a very common nosocomial infection in intensive care units (ICUs). Many studies have investigated risk factors for the development of infection and its consequences. However, the evaluation in most of theses studies disregards the fact that there are additional competing events, such as discharge or death. METHODS: A prospective cohort study was conducted over 18 months in five intensive care units at one university hospital. All patients that were admitted for at least 2 days were included, and surveillance of nosocomial pneumonia was conducted. Various potential risk factors (baseline- and time-dependent) were evaluated in two competing risks models: the acquisition of nosocomial pneumonia and discharge (dead or alive; model 1) and for the risk of death in the ICU and discharge alive (model 2). RESULTS: Patients from 1,876 admissions were included. A total of 158 patients developed nosocomial pneumonia. The main risk factors for nosocomial pneumonia in the multivariate analysis in model 1 were: elective surgery (cause-specific hazard ratio = 1.95; 95% CI 1.33 to 2.85) or emergency surgery (1.59; 95% CI 1.10 to 2.28) prior to ICU admission, usage of a nasogastric tube (3.04; 95% CI 1.25 to 7.37) and mechanical ventilation (5.90; 95% CI 2.47 to 14.09). Nosocomial pneumonia prolonged the length of ICU stay but was not directly associated with a fatal outcome (p = 0.55). CONCLUSION: More studies using competing risk models, which provide more accurate data compared to naive survival curves or logistic models, should be carried out to verify the impact of risk factors and patient characteristics for the acquisition of nosocomial infections and infection-associated mortality.

Transmission-associated nosocomial infections: prolongation of intensive care unit stay and risk factor analysis using multistate models.

BACKGROUND: Almost all studies investigating prolongation of stay because of nosocomial infections (NI) took into account all cases of NI, regardless whether they were associated with transmission of nosocomial pathogens (and therefore preventable) or not. We investigated the prolongation of intensive care unit (ICU) length of stay (LOS) because of transmission-associated NI (TANI) in a prospective study on 5 ICUs with normal NI rates over an 18-month period. METHODS: All clinical isolates and nose swabs were collected at admission. Pulsed-field gel electrophoresis and arbitrary primed polymerase length polymorphism methods were used for identifying transmissions. A NI was considered as TANI if indistinguishable pathogens were found in patients treated in temporal proximity and in the same ICU. Statistically, the temporal dynamics of the data were described by a multistate model. RESULTS: One thousand eight hundred seventy-six patients were observed for development of NI using the Centers for Disease Control and Prevention definitions; 341 patients acquired at least 1 NI (15.1 NI per 1000 patient-days), and 30 of these (8.8%) were considered to be infected with TANI. The influence of all NI as a time-dependent covariate in a proportional hazards model was significant (P < .0001) with an extra LOS of 5.3 days (+/-standard error, 1.6), as was the case for TANI alone (P = .02) with an extra LOS of 11.4 days (+/-7.3). However, TANI showed no significant effect compared with other NI (P = .23). The multivariate risk factor analysis showed that colostomy significantly increased the TANI hazard ratio (HR, 3.8; 95% CI: 1.0-14.3; P = .047) but did not significantly alter the HR for discharge or death without prior NI or for other NI. CONCLUSION: TANI occur in particular in patients with many manipulations and TANI significantly prolong ICU stay.

Antifungal use in intensive care units.

OBJECTIVES: To provide benchmarking data on antifungal use in intensive care units (ICUs), to analyse risk factors and to look for correlations with antibiotic use data and structure parameters. METHODS: Antimicrobial use data for 13 ICUs were obtained from computerized databases from January 2004 through June 2005. Antimicrobial usage density (AD) is expressed as daily defined doses/1000 patient-days. Correlations were calculated by the Spearman correlation or for binomic variables by the two-sided Wilcoxon test. A multivariate regression analysis was performed to identify independent risk factors for the outcome 'antifungal use'. RESULTS: Mean systemic antifungal drug use was 93.0, the range being between ADs of 18.9 and 232.2. ICUs treating transplant patients had a significantly higher mean antifungal usage at 152.9 compared with ICUs not treating transplant patients where the AD was 46.0. Fluconazole was the most frequently prescribed antifungal (mean AD 69.6) followed by amphotericin B (11.4) and voriconazole (6.2). Antifungal use correlated significantly with the consumption of quinolones, carbapenems and extended-spectrum penicillins, but not with total antibiotic use and not with the type of ICU or university status. In the multivariate linear regression analysis, two parameters, i.e. high quinolone use (P = 0.002) and ICUs which treat transplant patients (P = 0.027), were independent risk factors for a high level of antifungal use. CONCLUSIONS: Antifungal use was heterogeneous in German ICUs with the mean AD lying at 93. Benchmarking data might provide a useful method for assessing strategies that aim to reduce antifungal use in ICUs. However, data should be stratified for ICUs with and without transplant patients.

Modified guidelines impact on antibiotic use and costs: duration of treatment for pneumonia in a neurosurgical ICU is reduced.

OBJECTIVES: To evaluate the impact of an intervention to reduce the duration of antibiotic treatment for pneumonia in a neurosurgical intensive care unit (ICU). The usage of antibiotics and the resultant costs were examined using interrupted time series analysis while resistance and device-associated infection rates are also described. METHODS: In January 2004, revised guidelines for the use of antibiotics were implemented. As a consequence of this, the duration of antibiotic therapy for nosocomial pneumonia was reduced from 14 to 7 days, while for community-acquired pneumonia the period fell from 10 to 5 days. The effect on the antibiotic use density [AD; expressed as defined daily doses (DDD) per 1000 patient days (pd)] was calculated by segmented regression analysis of interrupted time series for the 24 months prior to (2002 and 2003) and after the intervention (2004 and 2005). RESULTS: The intervention was associated with a significant decrease in total AD from 949.8 to 626.7 DDD/1000 pd after the intervention. This was mainly due to reduced consumption of second-generation cephalosporins (-100.6 DDD/1000 pd), imidazoles (- 100.3 DDD/1000 pd), carbapenems (-33.3 DDD/1000 pd), penicillins with beta-lactamase inhibitor (-33.5 DDD/1000 pd) and glycopeptides (-30.2 DDD/1000 pd). Glycopeptide reduction might be associated with a significant decrease in the proportion of methicillin-resistant Staphylococcus aureus (8.4% before and 2.9% after the intervention). Similarly, total antibiotic costs/pd (Euro) showed a significant decrease from 13.16 Euro/pd before to 7.31 euro/pd after the intervention. This is a saving of 5.85 Euro/pd. The incidence of patients dying with pneumonia did not change significantly. CONCLUSIONS: The most conservative estimate of segmented regression analysis over a 48 month period showed that halving the duration of treatment for pneumonia results in a reduction of over 30% in antibiotic consumption and costs. Because respiratory infections are most common in ICU patients, interventions targeting a reduction in the duration of treatment of pneumonia might be extremely worthwhile.

Outbreaks in neonatal intensive care units - they are not like others.

BACKGROUND: Outbreaks of health care-associated infections in neonatal intensive care units (NICUs) are frequent and have received more attention in medical literature than outbreaks from other types of intensive care units (ICUs). The objective of this systematic review was to identify differences between outbreaks of health care-associated infections in NICUs and other ICUs as reported to date in the medical literature. METHODS: Screening the outbreak database (http://www.outbreak-database.com), a systematic comparison of outbreaks was performed with the following categories: causing pathogen, type of infection, sources identified, and measures taken to stop the outbreak. RESULTS: Two hundred and seventy-six outbreaks were reported from NICUs and 453 from other ICU types. Enterobacteriaceae were significantly more often responsible for NICU outbreaks, whereas nonfermenting bacteria are more frequently identified in other ICU types. On average, 23.9 patients and 1.8 health care workers were involved in NICU outbreaks. Average mortality in NICU outbreak was 6.4% (1.5 newborns on average). In 48.6% of NICU outbreaks the authors were unable to identify the sources compared with 38.0% in other ICU outbreaks. The most important infection control measures were significantly more often implemented in NICUs than in other ICUs. CONCLUSIONS: Systematic outbreak analysis is essential for gaining insights into the control of NICU outbreaks.

Development of a surveillance system for methicillin-resistant Staphylococcus aureus in German hospitals.

OBJECTIVE: To determine the appropriate method to calculate the rate of methicillin-resistant Staphylococcus aureus (MRSA) infection and colonization (hereafter, MRSA rates) for interhospital comparisons, such that the large number of patients who are already MRSA positive on admission is taken into account. DESIGN: A prospective, multicenter, hospital-based surveillance of MRSA-positive case patients from January through December 2004. SETTING: Data from 31 hospitals participating in the German national nosocomial infections surveillance system (KISS) were recorded during routine surveillance by the infection control team at each hospital. RESULTS: Data for 4,215 MRSA-positive case patients were evaluated. From this data, the following values were calculated. The median incidence density was 0.71 MRSA-positive case patients per 1,000 patient-days, and the median nosocomial incidence density was 0.27 patients with nosocomial MRSA infection or colonization per 1,000 patient-days (95% CI, 0.18-0.34). The median average daily MRSA burden was 1.13 MRSA patient-days per 100 patient-days (95% CI, 0.86-1.51), with the average daily MRSA burden defined as the total number of MRSA patient-days divided by the total number of patient-days times 100. The median MRSA-days-associated nosocomial MRSA infection and colonization rate, which describes the MRSA infection risk for other patients in hospitals housing large numbers of MRSA-positive patients and/or many patients who were MRSA positive on admission, was 23.1 cases of nosocomial MRSA infection and colonization per 1,000 MRSA patient-days (95% CI, 17.4-28.6). The values were also calculated for various MRSA screening levels. CONCLUSIONS: The MRSA-days-associated nosocomial MRSA rate allows investigators to assess the extent of MRSA colonization and infection at each hospital, taking into account cases that have been imported from other hospitals, as well as from the community. This information provides an appropriate incentive for hospitals to introduce further infection control measures.

Usefulness of severity-of-illness scores based on admission data only in nosocomial infection surveillance systems.

BACKGROUND: Surveillance of nosocomial infection (NI) and the use of reference data for comparison is recommended to improve the quality of patient care. In addition to standardization according to device use, another stratification of reference data according to patients' severity-of-illness scores is often required for benchmarking in intensive care units (ICUs). OBJECTIVE: To determine whether severity-of-illness scores on admission to the ICU are sufficient data for predicting the development of NI. METHODS: This study was performed in an interdisciplinary ICU at a teaching hospital. Two scores were studied: the Acute Physiology and Chronic Health Evaluation (APACHE) II scoring system and the Therapeutic Intervention Scoring System (TISS). The patient's clinical condition was evaluated on admission and reevaluated daily during the period before the development of NI. In addition, we recorded the number of intubations for every patient-day, the age and sex of the patients, and their history of operations. The Fisher exact test and the stepwise multiple logistic regression model were applied to identify significant predictors of NI. RESULTS: During a 12-month period, 270 patients with ICU stays of more than 24 hours were included in the study. Sixty-nine NIs were identified (incidence, 25.6 cases per 100 patients [95% confidence interval, 19.9-32.3]). A mean APACHE II score and a mean TISS score above the median for these scores, duration of ventilation above the median in the period before the development of NI, and patient age were significantly associated with the development of NI; the score data on admission provided a clearly poorer prediction. CONCLUSION: The APACHE II and TISS scores on admission are not useful predictors for NI in ICUs.

Where should one search when confronted with outbreaks of nosocomial infection?

The outbreak database (http://www.outbreak-database.com), containing 1561 records of nosocomial outbreaks published in the medical literature in a systematic format, was used to identify the most frequent outbreak sources for the entire database as well as for specific outbreak pathogens. Overall, in 37.1%, no source was identified. The main sources identified were index patients (40.3%), followed by equipment and devices (21.1%), environment (19.8%), and personnel (15.8%).

How often do asymptomatic healthcare workers cause methicillin-resistant Staphylococcus aureus outbreaks? A systematic evaluation.

A systematic search was performed to identify outbreaks of methicillin-resistant Staphylococcus aureus infection and colonization caused by healthcare workers (HCWs). Of 191 outbreaks identified, 11 had strong epidemiological evidence that HCWs were the source. In 3 of these outbreaks, asymptomatic carriers were the cause. The frequent practice of screening asymptomatic HCWs should be reconsidered.

Compliance with antiseptic hand rub use in intensive care units: the Hawthorne effect.

OBJECTIVE: To determine the influence the Hawthorne effect has on compliance with antiseptic hand rub (AHR) use among healthcare personnel. DESIGN: Observational study. SETTING: Five intensive care units of a university hospital in Berlin, Germany. PARTICIPANTS: Medical personnel were monitored in 2 periods regarding compliance with AHR use when there were indications for AHR use. In the first period, the personnel had no knowledge of being observed. The second observation period was announced to the staff of the intensive care units in advance and information about what the observer would be monitoring was provided. Potential confounders of compliance with AHR use included occupational groups (nurses, physicians, and other healthcare workers), intensive care units, and indications for AHR use before or after any procedure. RESULTS: Data were collected from 2,808 indications for AHR use. The overall rate of compliance was 29% (95% confidence interval, 26%-32%) in the first period and 45% (95% confidence interval, 43%-47%) in the second period. A logistic regression analysis with potential confounders revealed a significant odds ratio for the comparison between period 2 and period 1. The differences in compliance with AHR use were statistically significant (P<.001) between the occupational groups (nurses had the highest compliance and physicians had middle compliance) and between indication for AHR use before procedures and indication for AHR use after procedures. CONCLUSIONS: The Hawthorne effect has a marked influence on compliance with AHR use, with a 55% increase of compliance with overt observation. This result is consistent throughout subgroups. The rate of compliance with AHR use may in fact be lower than we thought because of results from studies that did not take the Hawthorne effect into account. The results of this study underline the necessity for infection control teams to be on wards as often as possible.

The influence of high-efficiency particulate air filtration on mortality and fungal infection among highly immunosuppressed patients: a systematic review.

BACKGROUND: Patients with hematological malignancies who are treated with intensive chemotherapy or who receive bone marrow transplants are exposed to an increased risk of developing nosocomial fungal infections. The aim of this systematic review was to compare the effectiveness of high-efficiency particulate air (HEPA) filtration with that of non-HEPA filtration in decreasing the rates of mortality and fungal infection among patients with diagnosed hematological malignancies and neutropenia or among patients with bone marrow transplants. METHODS: Articles identified in a Medline search, guidelines, and books, as well as the bibliographies of review articles, monographs, and the articles identified by Medline, were researched. Randomized trials and observational studies comparing HEPA filtration with conventional room ventilation were selected for inclusion in the present review. RESULTS: Sixteen trials (9 with death as an outcome and 10 with fungal infection as an outcome) that compared HEPA filtration with non-HEPA filtration were selected for meta-analyses. We discovered no significant advantages of HEPA filtration in the prevention of death among patients with hematological malignancies with severe neutropenia in randomized controlled trials (RCTs; relative risk [RR], 0.86 [95% confidence interval {CI}, 0.65-1.14]) and in studies of a lower standard (non-RCTs; RR, 0.87 [95% CI, 0.60-1.25]). CONCLUSIONS: The placement in protected areas of patients with hematological malignancies with severe neutropenia or patients with bone marrow transplants appears to be beneficial, but no definitive conclusion could be drawn from the data available.