Assessing the role of undetected colonization and isolation precautions in reducing Methicillin-Resistant Staphylococcus aureus transmission in intensive care units

<p>Abstract</p> <p>Background</p> <p>Screening and isolation are central components of hospital methicillin-resistant <it>Staphylococcus aureus </it>(MRSA) control policies. Their prevention of patient-to-patient spread depends on minimizing undetected and unisolated MRSA-positive patient days. Estimating these MRSA-positive patient days and the reduction in transmission due to isolation presents a major methodological challenge, but is essential for assessing both the value of existing control policies and the potential benefit of new rapid MRSA detection technologies. Recent methodological developments have made it possible to estimate these quantities using routine surveillance data.</p> <p>Methods</p> <p>Colonization data from admission and weekly nares cultures were collected from eight single-bed adult intensive care units (ICUs) over 17 months. Detected MRSA-positive patients were isolated using single rooms and barrier precautions. Data were analyzed using stochastic transmission models and model fitting was performed within a Bayesian framework using a Markov chain Monte Carlo algorithm, imputing unobserved MRSA carriage events.</p> <p>Results</p> <p>Models estimated the mean percent of colonized-patient-days attributed to undetected carriers as 14.1% (95% CI (11.7, 16.5)) averaged across ICUs. The percent of colonized-patient-days attributed to patients awaiting results averaged 7.8% (6.2, 9.2). Overall, the ratio of estimated transmission rates from unisolated MRSA-positive patients and those under barrier precautions was 1.34 (0.45, 3.97), but varied widely across ICUs.</p> <p>Conclusions</p> <p>Screening consistently detected >80% of colonized-patient-days. Estimates of the effectiveness of barrier precautions showed considerable uncertainty, but in all units except burns/general surgery and one cardiac surgery ICU, the best estimates were consistent with reductions in transmission associated with barrier precautions.</p

The Impact of Contact Isolation on the Quality of Inpatient Hospital Care

Background: Contact Isolation is a common hospital infection prevention method that may improve infectious outcomes but may also hinder healthcare delivery. Methods: To evaluate the impact of Contact Isolation on compliance with individual and composite process of care quality measures, we formed four retrospective diagnosis-based cohorts from a 662-bed tertiary-care medical center. Each cohor

An Isolator System for minimally invasive surgery: the new design

Background - The risk of obtaining a postsurgical infection depends highly on the air quality surrounding the exposed tissue, surgical instruments, and materials. Many isolators for open surgery have been invented to create a contained sterile volume around the exposed tissue. With the use of an isolator, a surgical procedure can be performed outside sterile environments. The goal of this study was to design an Isolator System (IS) for standard laparoscopic instruments while instrument movements are not restricted. Methods - The developed IS consists of a sleeve to protect the instrument shaft and tip and a special balloon to protect the incision and trocar tube. A coupling mechanism connected at the sleeve allows instrument changes without contamination of the isolated parts. Smoke tests were performed to show that outside air does not enter the new IS during a simulated laparoscopic procedure. Eight test runs and one baseline run inside a contained volume filled with thick smoke were performed to investigate whether smoke particles entered the Isolator System. Filters were used to identify smoke entering the Isolator System. Results - Seven filters showed no trace of smoke particles. In one test run, a part of the IS loosened and a small brown spot was visible. The filter from the baseline run was completely covered with a thick layer of particles, proving the effectiveness of the test. During all test runs, the isolated instrument was successfully locked on and unlocked from the isolated trocar. Instrument movements gave no complications. After removal of the isolated instrument, it took three novices an average of 3.1 (standard deviation (SD), 0.7) seconds to replace it correctly on the isolated trocar. Conclusions - The designed IS for laparoscopy can increase sterility in environments where sterility cannot be guaranteed. The current design is developed for laparoscopy, but it can easily be adapted for other fields in minimally invasive surgery.Biomechanical EngineeringMechanical, Maritime and Materials Engineerin

Core components for effective infection prevention and control programmes: new WHO evidence-based recommendations

Abstract Health care-associated infections (HAI) are a major public health problem with a significant impact on morbidity, mortality and quality of life. They represent also an important economic burden to health systems worldwide. However, a large proportion of HAI are preventable through effective infection prevention and control (IPC) measures. Improvements in IPC at the national and facility level are critical for the successful containment of antimicrobial resistance and the prevention of HAI, including outbreaks of highly transmissible diseases through high quality care within the context of universal health coverage. Given the limited availability of IPC evidence-based guidance and standards, the World Health Organization (WHO) decided to prioritize the development of global recommendations on the core components of effective IPC programmes both at the national and acute health care facility level, based on systematic literature reviews and expert consensus. The aim of the guideline development process was to identify the evidence and evaluate its quality, consider patient values and preferences, resource implications, and the feasibility and acceptability of the recommendations. As a result, 11 recommendations and three good practice statements are presented here, including a summary of the supporting evidence, and form the substance of a new WHO IPC guideline

Evaluation of routinely reported surgical site infections against microbiological culture results: a tool to identify patient groups where diagnosis and treatment may be improved

<p>Abstract</p> <p>Background</p> <p>Surgeons may improve their decision making by assessing the extent to which their initial clinical diagnosis of a surgical site infection (SSI) was supported by culture results. Aim of the present study was to evaluate routinely reported SSI by surgeons against microbiological culture results, to identify patient groups with lower agreement where decision making may be improved.</p> <p>Methods</p> <p>701 admissions with SSI were reported by surgeons in a university medical centre in the period 1997-2005, which were retrospectively checked for microbiological culture results. Reporting a SSI was conditional on treatment being given (e.g. antibiotics) and was classified by severity. To identify specific patient groups, patients were classified according to the surgery group of the first operation during admission (e.g. trauma).</p> <p>Results</p> <p>Of all reported SSI, 523 (74.6%) had a positive culture result, 102 (14.6%) a negative culture result and 76 (10.8%) were classified as unknown culture result (due to no culture taken). Given a known culture result, reported SSI with positive culture results less often concerned trauma patients (16% versus 26%, X²= 4.99 p = 0.03) and less severe SSI (49% versus 85%, X²= 10.11 p < 0.01) suggesting that a more conservative approach may be warranted in these patients. The trauma surgeons themselves perceived to have become too liberal in administering antibiotics (and reporting SSI).</p> <p>Conclusion</p> <p>Routine reporting of SSI was mostly supported by culture results. However, this support was less often found in trauma patients and less severe SSI, thereby giving surgeons feedback that diagnosis and treatment may be improved in these cases.</p

Direct medical costs of adverse events in Dutch hospitals

Background: Various international studies have shown that a substantial number of patients suffer from injuries or even die as a result of care delivered in hospitals. The occurrence of injuries among patients caused by health care management in Dutch hospitals has never been studied systematically. Therefore, an epidemiological study was initiated to determine the incidence, type and impact of adverse events among discharged and deceased patients in Dutch hospitals. Methods/Design: Three stage retrospective patient record review study in 21 hospitals of 8400 patient records of discharged or deceased patients in 2004. The records were reviewed by trained nurses and physicians between August 2005 and October 2006. In addition to the determination of presence, the degree of preventability, and causes of adverse events, also location, timing, classification, and most responsible specialty of the adverse events were measured. Moreover, patient and admission characteristics and the quality of the patient records were recorded. Discussion: In this paper we report on the design of the retrospective patient record study on the occurrence of adverse events in Dutch hospitals. Attention is paid to the strengths and limitations of the study design. Furthermore, alterations made in the original research protocol in comparison with former international studies are described in detail.

Surgical site infections in Italian Hospitals: a prospective multicenter study

<p>Abstract</p> <p>Background</p> <p>Surgical site infections (SSI) remain a major clinical problem in terms of morbidity, mortality, and hospital costs. Nearly 60% of SSI diagnosis occur in the postdischarge period. However, literature provides little information on risk factors associated to in-hospital and postdischarge SSI occurrence. A national prospective multicenter study was conducted with the aim of assessing the incidence of both in-hospital and postdisharge SSI, and the associated risk factors.</p> <p>Methods</p> <p>In 2002, a one-month, prospective national multicenter surveillance study was conducted in General and Gynecological units of 48 Italian hospitals. Case ascertainment of SSI was carried out using standardized surveillance methodology. To assess potential risk factors for SSI we used a conditional logistic regression model. We also reported the odds ratios of in-hospital and postdischarge SSI.</p> <p>Results</p> <p>SSI occurred in 241 (5.2%) of 4,665 patients, of which 148 (61.4%) during in-hospital, and 93 (38.6%) during postdischarge period. Of 93 postdischarge SSI, sixty-two (66.7%) and 31 (33.3%) were detected through telephone interview and questionnaire survey, respectively. Higher SSI incidence rates were observed in colon surgery (18.9%), gastric surgery (13.6%), and appendectomy (8.6%). If considering risk factors for SSI, at multivariate analysis we found that emergency interventions, NNIS risk score, pre-operative hospital stay, and use of drains were significantly associated with SSI occurrence. Moreover, risk factors for total SSI were also associated to in-hospital SSI. Additionally, only NNIS, pre-operative hospital stay, use of drains, and antibiotic prophylaxis were associated with postdischarge SSI.</p> <p>Conclusion</p> <p>Our study provided information on risk factors for SSI in a large population in general surgery setting in Italy. Standardized postdischarge surveillance detected 38.6% of all SSI. We also compared risk factors for in-hospital and postdischarge SSI, thus providing additional information to that of the current available literature. Finally, a large amount of postdischarge SSI were detected through telephone interview. The evaluation of the cost-effectiveness of the telephone interview as a postdischarge surveillance method could be an issue for further research.</p

Indicators of "Healthy Aging" in older women (65-69 years of age). A data-mining approach based on prediction of long-term survival

<p>Abstract</p> <p>Background</p> <p>Prediction of long-term survival in healthy adults requires recognition of features that serve as early indicators of successful aging. The aims of this study were to identify predictors of long-term survival in older women and to develop a multivariable model based upon longitudinal data from the Study of Osteoporotic Fractures (SOF).</p> <p>Methods</p> <p>We considered only the youngest subjects (<it>n </it>= 4,097) enrolled in the SOF cohort (65 to 69 years of age) and excluded older SOF subjects more likely to exhibit a "frail" phenotype. A total of 377 phenotypic measures were screened to determine which were of most value for prediction of long-term (19-year) survival. Prognostic capacity of individual predictors, and combinations of predictors, was evaluated using a cross-validation criterion with prediction accuracy assessed according to time-specific AUC statistics.</p> <p>Results</p> <p>Visual contrast sensitivity score was among the top 5 individual predictors relative to all 377 variables evaluated (mean AUC = 0.570). A 13-variable model with strong predictive performance was generated using a forward search strategy (mean AUC = 0.673). Variables within this model included a measure of physical function, smoking and diabetes status, self-reported health, contrast sensitivity, and functional status indices reflecting cumulative number of daily living impairments (HR ≥ 0.879 or RH ≤ 1.131; P < 0.001). We evaluated this model and show that it predicts long-term survival among subjects assigned differing causes of death (e.g., cancer, cardiovascular disease; P < 0.01). For an average follow-up time of 20 years, output from the model was associated with multiple outcomes among survivors, such as tests of cognitive function, geriatric depression, number of daily living impairments and grip strength (P < 0.03).</p> <p>Conclusions</p> <p>The multivariate model we developed characterizes a "healthy aging" phenotype based upon an integration of measures that together reflect multiple dimensions of an aging adult (65-69 years of age). Age-sensitive components of this model may be of value as biomarkers in human studies that evaluate anti-aging interventions. Our methodology could be applied to data from other longitudinal cohorts to generalize these findings, identify additional predictors of long-term survival, and to further develop the "healthy aging" concept.</p