The Michigan Risk Score to predict peripherally inserted central catheter-associated thrombosis.

Essentials How best to quantify thrombosis risk with peripherally inserted central catheters (PICC) is unknown. Data from a registry were used to develop the Michigan Risk Score (MRS) for PICC thrombosis. Five risk factors were associated with PICC thrombosis and used to develop a risk score. MRS was predictive of the risk of PICC thrombosis and can be useful in clinical practice. SUMMARY: Background Peripherally inserted central catheters (PICCs) are associated with upper extremity deep vein thrombosis (DVT). We developed a score to predict risk of PICC-related thrombosis. Methods Using data from the Michigan Hospital Medicine Safety Consortium, image-confirmed upper-extremity DVT cases were identified. A logistic, mixed-effects model with hospital-specific random intercepts was used to identify factors associated with PICC-DVT. Points were assigned to each predictor, stratifying patients into four classes of risk. Internal validation was performed by bootstrapping with assessment of calibration and discrimination of the model. Results Of 23 010 patients who received PICCs, 475 (2.1%) developed symptomatic PICC-DVT. Risk factors associated with PICC-DVT included: history of DVT; multi-lumen PICC; active cancer; presence of another CVC when the PICC was placed; and white blood cell count greater than 12 000. Four risk classes were created based on thrombosis risk. Thrombosis rates were 0.9% for class I, 1.6% for class II, 2.7% for class III and 4.7% for class IV, with marginal predicted probabilities of 0.9% (0.7, 1.2), 1.5% (1.2, 1.9), 2.6% (2.2, 3.0) and 4.5% (3.7, 5.4) for classes I, II, III, and IV, respectively. The risk classification rule was strongly associated with PICC-DVT, with odds ratios of 1.68 (95% CI, 1.19, 2.37), 2.90 (95% CI, 2.09, 4.01) and 5.20 (95% CI, 3.65, 7.42) for risk classes II, III and IV vs. risk class I, respectively. Conclusion The Michigan PICC-DVT Risk Score offers a novel way to estimate risk of DVT associated with PICCs and can help inform appropriateness of PICC insertion.

Can intersectional innovations reduce hospital infection?

Preventing healthcare-associated infection remains an international priority given the clinical and economic consequences of this largely preventable patient safety harm. Whereas important strides have been made in preventing hospital infections over the past several decades, thorny issues remain, including how to consistently improve hand hygiene rates and further reduce device-related complications such as catheter-associated urinary tract infection. Rather than relying solely on directional innovations - incremental changes that continue to serve as the bedrock of scientific advancement - perhaps we should also search for 'intersectional innovations', which represent breakthrough discoveries that emanate from the intersection of often widely divergent disciplines. Several intersectional innovations that have the potential to greatly impact infection prevention efforts include human factors engineering, sociology, and engaging the senses. Indeed, Professor Edward Joseph Lister Lowbury, the namesake of this lecture, exemplified intersectional thinking in his own life, having been both an accomplished bacteriologist and poet. By incorporating approaches outside of traditional biomedical science we may hope to provide patients with the safe care they expect and deserve.

Epidemiological impact of mass tuberculosis screening: a 2-year follow-up after a national prevalence survey.

OBJECTIVE: To assess the epidemiological impact of mass tuberculosis (TB) screening in the community and the prognosis of bacteriologically negative individuals with abnormal findings on chest radiography (CXR). METHODS: A follow-up study consisting of two parts--a register match of notified TB cases with 22,160 participants in a national TB prevalence survey, and a repeat medical examination for the subjects of a prevalence survey with abnormal findings on CXR--was conducted 2 years after the prevalence survey in Cambodia. RESULTS: Thirty-four cases with new smear-positive TB were detected by register match, giving a standardised notification ratio of 0.38 (95%CI 0.27-0.52). An additional seven new smear-positive TB cases and 93 new smear-negative, culture-positive TB cases were detected by medical examination. The incidence rates of bacteriologically positive TB were 8.5% per year (95%CI 6.3-11.2) in cases with a CXR suggestive of active TB and 2.9% per year (95%CI 2.2-3.7) in those with a CXR with other abnormalities. CONCLUSIONS: Detection and treatment of smear-negative, culture-positive TB cases as well as smear-positive TB cases was associated with a rapid reduction in subsequent incidence of new smear-positive TB. Sputum culture-negative individuals with abnormal CXR findings are at a high risk of disease progression, and require follow-up and potentially preventive treatment.

Improving healthcare worker hand hygiene adherence before patient contact: a before-and-after five-unit multimodal intervention in Tuscany.

BACKGROUND: Despite the importance of hand hygiene in reducing infection, healthcare worker compliance with hand hygiene recommendations remains low. In a previous study, we found a generally low level of compliance at baseline, with substantial differences between doctors and nurses and between hospital units. We describe here the results of our multimodal intervention intended to improve levels of healthcare worker hand hygiene. METHODS: A 6-month, before-and-after, multimodal interventional study in five hospital units in Florence, Italy. We used direct observation to assess hand hygiene rates for doctors and nurses, focusing on hygiene before touching the patient. We explored reasons for unit variability via interviews of doctor and nurse leaders on the units. RESULTS: Overall healthcare worker hand hygiene increased from 31.5% to 47.4% (p<0.001). Hand hygiene adherence among nurses increased from 33.7% to 47.9% (p<0.001); adherence among doctors increased from 27.5% to 46.6% (p<0.001). Improvement was statistically significant in three out of five units, and units differed in the magnitude of their improvement. Based on the interviews, variability appeared related to the "champion" on each unit, as well as the level of motivation each physician leader exhibited when the preintervention results were provided. CONCLUSIONS: Although overall healthcare worker adherence with hand hygiene procedures before patient contact substantially increased after the multimodal intervention, considerable variability-for both nurses and doctors and across the 5 units-was seen. Although adherence substantially increased, overall hand hygiene in these units could still be greatly improved.

The role of the champion in infection prevention: results from a multisite qualitative study.

BACKGROUND: Although 20% or more of healthcare-associated infections can be prevented, many hospitals have not implemented practices known to reduce infections. We explored the types and numbers of champions who lead efforts to implement best practices to prevent hospital-acquired infection in US hospitals. METHODS: Qualitative analyses were conducted within a multisite, sequential mixed methods study of infection prevention practices in Veteran Affairs and non-Veteran Affairs hospitals in the USA. The first phase included telephone interviews conducted in 2005-2006 with 38 individuals at 14 purposively selected hospitals. The second phase used findings from phase 1 to select six hospitals for site visits and interviews with another 48 individuals in 2006-2007. RESULTS: It was possible for a single well-placed champion to implement a new technology, but more than one champion was needed when an improvement required people to change behaviours. Although the behavioural change itself may appear to be an inexpensive and simple solution, implementation was often more complicated than changing technology because behavioural changes required interprofessional coalitions working together. Champions in hospitals with low-quality working relationships across units or professions had a particularly challenging time implementing behavioural change. Merely appointing champions is ineffective; rather, successful champions tended to be intrinsically motivated and enthusiastic about the practices they promoted. Even when broad implementation is stymied, champions can implement change within their own sphere of influence. CONCLUSIONS: The types and numbers of champions varied with the type of practice implemented and the effectiveness of champions was affected by the quality of organisational networks.

Performance of an interferon-gamma release assay for diagnosing latent tuberculosis infection in children.

Newly developed interferon-gamma release assays have become commercially available to detect tuberculosis (TB) infection in adults. However, little is known about their performance in children. We compared test results between the QuantiFERON-TB Gold test (QFT) and tuberculin skin test (TST) in young children living with pulmonary TB patients in Cambodia. Of 195 children tested with both QFT and TST, the TST-positive rate of 24% was significantly higher than the QFT-positive rate of 17%. The agreement between the test results was considerable (kappa-coefficient 0.63). Positive rates increased from 6% to 32% for QFT and from 15% to 43% for TST, according to the sputum smear grades of the index cases. The presence of Bacille Calmette-Guérin (BCG) scars did not significantly affect the results of TST or QFT in a logistic regression analysis. In conclusion, QFT can be a substitute for TST in detecting latent TB infection in childhood contacts aged

The role of hospital volume in coronary artery bypass grafting: is more always better?

OBJECTIVES: The goal of this study was to determine whether outcomes of nonemergent coronary artery bypass grafting (CABG) differed between low- and high-volume hospitals in patients at different levels of surgical risk. BACKGROUND: Regionalizing all CABG surgeries from low- to high-volume hospitals could improve surgical outcomes but reduce patient access and choice. "Targeted" regionalization could be a reasonable alternative, however, if subgroups of patients that would clearly benefit from care at high-volume hospitals could be identified. METHODS: We assessed outcomes of CABG at 56 U.S. hospitals using 1997 administrative and clinical data from Solucient EXPLORE, a national outcomes benchmarking database. Predicted in-hospital mortality rates for subjects were calculated using a logistic regression model, and subjects were classified into five groups based on surgical risk: minimal (< 0.5%), low (0.5% to 2%), moderate (2% to 5%), high (5% to 20%), and severe (> or =20%). We assessed differences in in-hospital mortality, hospital costs and length of stay between low- and high-volume facilities (defined as > or =200 annual cases) in each of the five risk groups. RESULTS: A total of 2,029 subjects who underwent CABG at 25 low-volume hospitals and 11,615 subjects who underwent CABG at 31 high-volume hospitals were identified. Significant differences in in-hospital mortality were seen between low- and high-volume facilities in subjects at moderate (5.3% vs. 2.2%; p = 0.007) and high risk (22.6% vs. 11.9%; p = 0.0026) but not in those at minimal, low or severe risk. Hospital costs and lengths of stay were similar across each of the five risk groups. Based on these results, targeted regionalization of subjects at moderate risk or higher to high-volume hospitals would have resulted in an estimated 370 transfers and avoided 16 deaths; in contrast, full regionalization would have led to 2,029 transfers and avoided 20 deaths. CONCLUSIONS: Targeted regionalization might be a feasible strategy for balancing the clinical benefits of regionalization with patients' desires for choice and access.

Diagnosis and treatment of upper respiratory tract infections in the primary care setting.

BACKGROUND: Acute respiratory tract infections such as acute exacerbations of chronic bronchitis (AECB), acute otitis media (AOM), and acute bacterial rhinosinusitis (ABRS) account for approximately 75% of antibiotic prescriptions written and are among the leading reasons for physician office visits in the United States. Resistance of the predominant pathogens in respiratory tract infections (Streptococcus pneumoniae, Haemophilus influenzae, and Moraxella catarrhalis) to available antibiotics has led clinicians to reevaluate the diagnosis and management of these infections. OBJECTIVE: The purpose of this review is to provide primary care practitioners with an accessible combined resource for the management of AECB, AOM, and ABRS. METHODS: This review was based on discussions from a roundtable meeting (sponsored by an educational grant from GlaxoSmithKline) that convened clinicians versed in the management of upper and lower respiratory tract infections. In addition, primary articles were identified by a MEDLINE search and through secondary sources. RESULTS: To reduce the prevalence of resistance, judicious and appropriate use of antibiotics must be implemented in clinical practice. With accurate diagnosis of bacterial and nonbacterial conditions, and patient education on antibiotic use and misuse, the excessive use of antibiotics and ensuing resistance can be reduced. The incorporation of pharmacokinetic and pharmacodynamic data with minimum inhibitory concentration values can provide a more comprehensive assessment of antibiotic activity in vivo. Stratification of patients with AECB according to patient characteristics and frequency of exacerbation can be used to determine which patients will benefit from antibiotic treatment and to guide clinicians in their choice of antibiotic. The Drug-Resistant Streptococcus pneumoniae Therapeutic Working Group has issued recommendations on the management of AOM based on prior antibiotic therapy, which is a risk factor for antimicrobial resistance. The Sinus and Allergy Health Partnership guidelines for the treatment of ABRS in adults and children are based on the predicted efficacy of various antibiotics as well as patient age, severity of disease, likelihood of bacterial infection, likelihood of spontaneous resolution, and in vitro susceptibility of the predominant pathogens based on pharmacokinetic and pharmacodynamic breakpoints. CONCLUSIONS: Guidelines for the management of AECB, AOM, and ABRS emphasize the importance of differentiating between bacterial and nonbacterial infections, choosing an antibiotic based on the likelihood of infection with resistant pathogens, and providing coverage against the predominant pathogens. The judicious use of antibiotics also has been identified as an instrumental part of controlling unnecessary antibiotic use and subsequent resistance.

Four-year prospective evaluation of community-acquired bacteremia: epidemiology, microbiology, and patient outcome.

The objectives of this study were to (1) describe the epidemiology and microbiology of community-acquired bacteremia; (2) determine the crude mortality associated with such infections; and (3) identify independent predictors of mortality. All patients with clinically significant community-acquired bacteremia admitted to a university-affiliated Veterans Affairs medical center from January 1994 through December 1997 were evaluated. During the study period, 387 bacteremic episodes occurred in 334 patients. Staphylococcus aureus, Escherichia coli, and coagulase-negative staphylococci were the most commonly isolated organisms; the most frequent sources were the urinary tract and intravascular catheters. Approximately 14% of patients died. Patient characteristics independently associated with increased mortality included shock (OR 3.7, p = 0.02) and renal failure (OR 4.0, p = 0.003). The risk of death was also higher in those whose source was pneumonia (OR 6.3, p = 0.03) or an intra-abdominal site (OR 10.7, p = 0.02), or if multiple sources were identified (OR 13.4, p = 0.003). Community-acquired bacteremia is often device-related and may be preventable. Strategies that have been successful in preventing nosocomial device-related bacteremia should be adapted to the outpatient setting.

The role of economic evaluation in infection control.

Given the rise in health care-related expenditures, decision-makers are increasingly relying on both clinical effectiveness and economic efficiency when making health care decisions. The field of infection control is not immune to this rise in cost-consciousness among health care managers. This article clarifies the role of economic evaluation within infection control for both the user and producer of economic evaluations in this field. The strengths and drawbacks of the several different types of economic analysis--cost minimization, cost-effectiveness, cost-benefit, and cost utility analysis--will be discussed. Additionally, the important features of two specific methods used for economic evaluation-decision analytic modeling and economic analysis alongside a clinical trial-will be outlined. Finally, the criteria by which economic analyses should be judged will be provided. As economic evaluation and health services research continue to play an increasingly important role in health care, it will be vital for infection control advocates to partner with individuals from diverse fields to give decision-makers the type of information they need to make choices.

Coronary artery bypass grafting in Native Americans: a higher risk of death compared to other ethnic groups?

BACKGROUND: While the efficacy and safety of coronary artery bypass grafting (CABG) has been established in several clinical trials, little is known about its outcomes in Native Americans. MEASUREMENTS AND MAIN RESULTS: We assessed clinical outcomes associated with CABG in 155 Native Americans using a national database of 18,061 patients from 25 nongovernmental, not-for-profit U.S. health care facilities. Patients were classified into five groups: 1) Native American, 2) white, 3) African American, 4) Hispanic, and 5) Asian. We evaluated for ethnic differences in in-hospital mortality and length of stay, and after adjusting for age, gender, surgical priority, case-mix severity, insurance status, and facility characteristics (volume, location, and teaching status). Overall, we found the adjusted risk for in-hospital death to be higher in Native Americans when compared to whites (odds ratio [OR], 3.8; 95% confidence interval [CI], 1.5 to 9.8), African Americans (OR, 3.4; 95% CI, 1.1 to 9.9), Hispanics (OR, 7.1; 95% CI, 2.5 to 20.3), and Asians (OR, 2.8; 95% CI, 1.1 to 7.0). No significant differences were found in length of stay after adjustment across ethnic groups. CONCLUSIONS: The risk of in-hospital death following CABG may be higher in Native Americans than in other ethnic groups. Given the small number of Native Americans in the database (n = 155), however, further research will be needed to confirm these findings.

Structure, activity and evolution of the group I thiolactone peptide quorum-sensing system of Staphylococcus aureus.

In Staphylococcus aureus, the agr locus is responsible for controlling virulence gene expression via quorum sensing. As the blockade of quorum sensing offers a novel strategy for attenuating infection, we sought to gain novel insights into the structure, activity and turnover of the secreted staphylococcal autoinducing peptide (AIP) signal molecules. A series of analogues (including the L-alanine and D-amino acid scanned peptides) was synthesized to determine the functionally critical residues within the S. aureus group I AIP. As a consequence, we established that (i) the group I AIP is inactivated in culture supernatants by the formation of the corresponding methionyl sulphoxide; and (ii) the group I AIP lactam analogue retains the capacity to activate agr, suggesting that covalent modification of the AgrC receptor is not a necessary prerequisite for agr activation. Although each of the D-amino acid scanned AIP analogues retained activity, replacement of the endocyclic amino acid residue (aspartate) located C-terminally to the central cysteine with alanine converted the group I AIP from an activator to a potent inhibitor. The screening of clinical S. aureus isolates for novel AIP groups revealed a variant that differed from the group I AIP by a single amino acid residue (aspartate to tyrosine) in the same position defined as critical by alanine scanning. Although this AIP inhibits group I S. aureus strains, the producer strains possess a functional agr locus dependent on the endogenous peptide and, as such, constitute a fourth S. aureus AIP pheromone group (group IV). The addition of exogenous synthetic AIPs to S. aureus inhibited the production of toxic shock syndrome toxin (TSST-1) and enterotoxin C3, confirming the potential of quorum-sensing blockade as a therapeutic strategy.

Research Priorities Project, year 2000: establishing a direction for infection control and hospital epidemiology.

BACKGROUND: The field called "infection control" has expanded beyond hospitals to include many health care locations, some aspects of personnel health, elements of noninfectious complications, and occasionally the epidemiology of other problems that occur in care facilities. A research agenda that addresses these newer segments and provides a framework for answering fundamental questions is essential for the field and for the work of The Research Foundation for Prevention of Complications Associated with Health Care (formerly APIC Research Foundation). METHODS: We used a multiple-round iterative consensus process (Delphi technique) with 50 experts and a validation round among participants at the 4th Decennial Conference. RESULTS: The expert panel reduced 102 separate items to 21 high-ranked research priorities. The highest-ranked subject areas involved research to improve compliance with excellent practices, to study antibiotic usage and resistance, to measure the financial impact of complications and value of interventions, to perform surveillance of infectious and noninfectious complications across the spectrum of care delivery, and to study effectiveness of interventions to prevent complications at specific sites. There were differences in education and discipline between the expert panel and the 4th Decennial participants and with respect to ranking some of the individual priorities. Among respondents from outside the United States and Canada, occupational health issues were ranked more highly. CONCLUSIONS: The research priorities provide a blueprint for future progress and will require a collaborative, multicenter, multinational approach.

Acute exacerbation of chronic bronchitis: disease-specific issues that influence the cost-effectiveness of antimicrobial therapy.

BACKGROUND: Acute exacerbation of chronic bronchitis (AECB) is a common condition, with substantial associated costs and morbidity. Research efforts have focused on innovations that will reduce the morbidity associated with AECB. Health care payers increasingly expect that the results of evidence-based economic evaluations will guide practitioners in their choice of cost-effective interventions. OBJECTIVES: To provide a framework on which to base effective and efficient antimicrobial therapy for AECB, we present a concise clinical review of AECB, followed by an assessment of the available data on the economic impact of this disease. We then address several AECB-specific issues that must be considered in cost-effectiveness analyses of AECB antimicrobial interventions. METHODS: Published literature on the clinical and economic impact of AECB was identified using MEDLINE, pre-MEDLINE, HealthSTAR, CINAHL, Current Contents/All Editions, EMBASE, and International Pharmaceutical Abstracts databases. Other potential sources were identified by searching for references in retrieved articles, review articles, consensus statements, and articles written by selected authorities. RESULTS: In evaluating cost-effectiveness analyses of AECB antimicrobial therapy it is critical to (1) use the disease-free interval as an outcome measure, (2) evaluate the sequence of multiple therapies, (3) address the impact of both current and future antibiotic resistance, and (4) measure all appropriate AECB-associated costs, both direct and indirect. CONCLUSIONS: Incorporating these approaches in economic analyses of AECB antimicrobial therapy can help health care organizations make evidence-based decisions regarding the cost-effective management of AECB.

Electron-beam computed tomography in the diagnosis of coronary artery disease: a meta-analysis.

BACKGROUND: Electron-beam computed tomography (EBCT) is a new, noninvasive method of detecting coronary artery calcification that is being increasingly advocated as a diagnostic test for coronary artery disease (CAD). Before its clinical use is justified, however, the overall accuracy of EBCT must be better defined. OBJECTIVE: To estimate the accuracy of EBCT in diagnosing obstructive CAD. DATA SOURCES: English-language studies from January 1, 1979, through February 29, 2000, were retrieved using MEDLINE and Current Contents databases, bibliographies, and expert consultation. STUDY SELECTION: We included a study if it (1) used EBCT as a diagnostic test; (2) reported cases in absolute numbers of true-positive, false-positive, true-negative, and false-negative results; and (3) used coronary angiography as the reference standard for diagnosing obstructive CAD (defined as > or = 50% diameter stenosis). DATA EXTRACTION: Data were extracted from the included articles by 2 independent reviewers. DATA SYNTHESIS: Weighted pooled analysis and summary receiver operating characteristic (ROC) curve analysis were used to determine sensitivity and specificity rates. Results from 9 studies with 1662 subjects were included. Pooled sensitivity for EBCT was 92.3% (95% confidence interval [CI], 90.7%-94.0%) and pooled specificity was 51.2% (95% CI, 47.5%-54.9%). Maximum joint sensitivity and specificity for EBCT from its summary ROC curve was 75%. As the threshold for defining an abnormal test varied, sensitivity and specificity changed. For a threshold that resulted in a sensitivity of 90%, specificity was 54%; when sensitivity was 80%, specificity rose to 71%. CONCLUSION: The performance of EBCT as a diagnostic test for obstructive CAD is reasonable based on sensitivity and specificity rates from its summary ROC curve.

The spectrum of acute bronchitis. Using baseline factors to guide empirical therapy.

The optimal therapy for acute bronchitis depends on the causative pathogen and the presence or absence of underlying lung disease. Because there is no fast, reliable way to identify the pathogen, physicians have to rely on clinical judgment and epidemiologic characteristics. In this article, Drs Flaherty, Saint, Fendrick, and Martinez discuss how an evidence-based approach to treatment may help ensure that efficacious therapy is available in the future.

Four year prospective evaluation of nosocomial bacteremia: epidemiology, microbiology, and patient outcome.

A prospective study of all patients with clinically significant nosocomial bacteremia at one institution from 1994 to 1997 was performed to: (1) describe the epidemiology and microbiology of nosocomial bacteremias; (2) determine the crude mortality associated with such infections; and (3) identify independent predictors of mortality. Four hundred four episodes of bacteremia occurred in 322 patients; the crude in-hospital mortality was 31%. Coagulase-negative staphylococci, Staphylococcus aureus, and enterococci were the leading pathogens, and intravascular catheters were the most frequently identified source. The highest mortality occurred in patients with candidemia (67%). Independent predictors of mortality included evidence of shock at the time of infection, acquisition of bacteremia in an intensive care unit, a "Do Not Attempt Resuscitation" order, and the presence of certain comorbid conditions (e.g., malignancy, HIV infection). Because many of these infections may be preventable, education of health care providers and strict adherence to established infection control practices are critical.