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.

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.

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.

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 Collapse

Key Words Collapse

MESH Headings

• Cambodia
• Chi-Square Distribution
• Child, Preschool
• Female
• Humans
• Infant
• Infant, Newborn
• Interferon-gamma/blood
• Male
• Sensitivity and Specificity
• Tuberculin Test
• Tuberculosis, Pulmonary/diagnosis

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Grants Collapse

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.

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.

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.

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.

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.

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.

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.

Potential clinical and economic effects of homocyst(e)ine lowering

BACKGROUND

Elevated total homocyst(e)ine levels (>/=11 micromol/L) have been identified as a potential risk factor for coronary heart disease. However, the benefits expected from lowering homocyst(e)ine levels with folic acid and vitamin B(12) supplementation have yet to be demonstrated in clinical trials.

SUBJECTS AND METHODS

We constructed a decision analytic model to estimate the clinical benefits and economic costs of 2 homocyst(e)ine-lowering strategies: (1) "treat all"-no screening, daily supplementation with folic acid (400 microg) and vitamin B(12) (cyanocobalamin; 500 microg) for all; (2) "screen and treat"-screening, followed by daily supplementation with folic acid and vitamin B(12) for individuals with elevated homocyst(e)ine levels. Simulated cohorts of 40-year-old men and 50-year-old women in the general population were evaluated. In the base-case analysis, we assumed that lowering elevated levels would reduce excess coronary heart disease risk by 40%; however, this assumption and others were evaluated across a broad range of potential values using sensitivity analysis. Primary outcomes were discounted costs per life-year saved.

RESULTS

Although the treat-all strategy was slightly more effective overall, the screen and treat strategy resulted in a much lower cost per life-year saved ($13,600 in men and $27,500 in women) when compared with no intervention. Incremental cost-effectiveness ratios for the treat-all strategy compared with the screen and treat strategy were more than $500,000 per life-year saved in both cohorts. Sensitivity analysis showed that cost-effectiveness ratios for the screen and treat strategy remained less than $50,000 per life-year saved under several unfavorable scenarios, such as when effective homocyst(e)ine lowering was assumed to reduce the relative risk of coronary heart disease-related death by only 11% in men or 23% in women.

CONCLUSIONS

Homocyst(e)ine lowering with folic acid and vitamin B(12) supplementation could result in substantial clinical benefits at reasonable costs. If homocyst-(e)ine lowering is considered, a screen and treat strategy is likely to be more cost-effective than universal supplementation. Arch Intern Med. 2000;160:3406-3412.

Journal reading habits of internists

We assessed the reading habits of internists with and without epidemiological training because such information may help guide medical journals as they make changes in how articles are edited and formatted. In a 1998 national self-administered mailed survey of 143 internists with fellowship training in epidemiology and study design and a random sample of 121 internists from the American Medical Association physician master file, we asked about the number of hours spent reading medical journals per week and the percentage of articles for which only the abstract is read. Respondents also were asked which of nine medical journals they subscribe to and read regularly. Of the 399 eligible participants, 264 returned surveys (response rate 66%). Respondents reported spending 4.4 hours per week reading medical journal articles and reported reading only the abstract for 63% of the articles; these findings were similar for internists with and without epidemiology training. Respondents admitted to a reliance on journal editors to provide rigorous and useful information, given the limited time available for critical reading. We conclude that internists, regardless of training in epidemiology, rely heavily on abstracts and prescreening of articles by editors.

Antimicrobial resistance in Streptococcus pneumoniae: implications for patients with community-acquired pneumonia

Streptococcus pneumoniae is the leading cause of community-acquired pneumonia. During the past decade, the prevalence of penicillin resistance in S pneumoniae has increased dramatically, with resistance rates approaching 45% in some areas of the United States. Streptococcus pneumoniae has also acquired resistance to other commonly used antimicrobials, including cephalosporins, macrolides, and trimethoprim-sulfamethoxazole. While vancomycin and the newer quinolones are currently highly active against most strains of S pneumoniae, reduced susceptibilities to these agents have been identified in some strains. Prior use of antimicrobial agents is the major risk factor for colonization and infection with antibiotic-resistant strains. beta-Lactam antibiotics remain the treatment of choice for infections caused by susceptible S pneumoniae. The optimum therapy for penicillin-resistant strains remains unclear. Appropriate empirical therapy for patients with community-acquired pneumonia depends in part on the community-specific resistance patterns of S pneumoniae to various antibiotics. In this article, we provide an overview of the development of S pneumoniae resistance to commonly used antibiotics and discuss the implications of the development of resistance on treatment decisions.

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.

Are physicians aware of which of their patients have indwelling urinary catheters?

PURPOSE

Although infections associated with indwelling urinary catheters are common, costly, and morbid, the use of these catheters is unnecessary in more than one-third of patients. We sought to assess whether attending physicians, medical residents, and medical students are aware if their hospitalized patients have an indwelling urinary catheter, and whether physician awareness is associated with appropriate use of these catheters.

METHODS

The physicians and medical students responsible for patients admitted to the medical services at four university-affiliated hospitals were given a list of the patients on their service. For each patient, the provider was asked: "As of yesterday afternoon, did this patient have an indwelling urethral catheter?" Respondents' answers were compared with the results of examining the patient.

RESULTS

Among 288 physicians and students on 56 medical teams, 256 (89%) completed the survey. Of 469 patients, 117 (25%) had an indwelling catheter. There were a total of 319 provider-patient observations among these 117 patients. Overall, providers were unaware of catheterization for 88 (28%) of the 319 provider-patient observations. Unawareness rates by level of training were 21% for students, 22% for interns, 27% for residents, and 38% for attending physicians (P = 0.06). Catheter use was inappropriate in 36 (31%) of the 117 patients with a catheter. Providers were unaware of catheter use for 44 (41%) of the 108 provider-patient observations of patients who were inappropriately catheterized. Catheterization was more likely to be appropriate if respondents were aware of the catheter (odds ratio = 3.7; 95% confidence interval, 2.1 to 6.7, P <0.001).

CONCLUSION

Physicians are commonly unaware that their patients have an indwelling urinary catheter. Inappropriate catheters are more often "forgotten" than appropriate ones. System-wide interventions aimed at discontinuing unnecessary catheterization seem warranted.

The potential clinical and economic benefits of silver alloy urinary catheters in preventing urinary tract infection

BACKGROUND

Catheter-associated urinary tract infection (UTI) is associated with increased morbidity, mortality, and costs. A recent meta-analysis concluded that silver alloy catheters reduce the incidence of UTI by 3-fold; however, clinicians must decide whether the efficacy of such catheters is worth the extra per unit cost of $5.30.

OBJECTIVE

To assess the clinical and economic impact of using silver alloy urinary catheters in hospitalized patients.

METHODS

The decision model, performed from the health care payer's perspective, evaluated a simulated cohort of 1000 hospitalized patients on general medical, surgical, urologic, and intensive care services requiring short-term urethral catheterization (2-10 days). We compared 2 catheterization strategies: silver alloy catheters and standard (noncoated) urinary catheters. Outcomes included the incidence of symptomatic UTI and bacteremia and direct medical costs.

RESULTS

In the base-case analysis, use of silver-coated catheters led to a 47% relative decrease in the incidence of symptomatic UTI from 30 to 16 cases per 1000 patients (number needed to treat = 74) and a 44% relative decrease in the incidence of bacteremia from 4.5 to 2.5 cases per 1000 patients (number needed to treat = 500) compared with standard catheters. Use of silver alloy catheters resulted in estimated cost savings of $4.09 per patient compared with standard catheter use ($20.87 vs $16.78). In a multivariate sensitivity analysis using Monte Carlo simulation, silver-coated catheters provided clinical benefits over standard catheters in all cases and cost savings in 84% of cases.

CONCLUSIONS

Using silver alloy catheters in hospitalized patients requiring short-term urinary catheterization reduces the incidence of symptomatic UTI and bacteremia, and is likely to produce cost savings compared with standard catheters.

Do physicians judge a study by its cover? An investigation of journal attribution bias

The effect of a journal's prestige on readers' impressions of an article is unknown. Two hypotheses were tested: first, that attribution of a study to a "high" prestige journal would be associated with improved impressions and attribution to a "low" prestige journal would be associated with diminished impressions; and second, that formal training in epidemiology and biostatistics would mitigate the effects of this journal attribution bias. The study was designed as a trial among a random sample of 264 internists. Participants were asked to read an article and an abstract from either the Southern Medical Journal (SMJ) or the New England Journal of Medicine (NEJM). Questionnaires were constructed that either attributed the article or abstract to its source or presented it as unattributed. After each article or abstract, respondents were asked to rate the quality of the study, the appropriateness of the methodology employed, the significance of the findings, and its likely effects on their practice. A 20-point impression score was created based on responses to these statements. The effect of attribution to a specific journal and formal epidemiology training on impression scores were assessed using linear regression. Of the 399 eligible participants, 264 questionnaires were returned (response rate 66%). Differences in impression scores associated with attribution of an article or abstract to the NEJM were.71 [95% C.I. (-.44-1.87)] and.50 [95% C.I. (-.87-1.87)] respectively; differences in impression scores associated with attribution of an article or abstract to the SMJ were -.12 [95% C.I. (-1.53-1.30)] and -.95 [95% C.I. (-2.41-.52)]. A stratified analysis demonstrated that epidemiology training did not meaningfully alter the effect of journal attribution on participants' impression scores. If journal attribution bias exists, it is likely to exert small and clinically insignificant effects when physicians read articles carefully. Formal training in epidemiology and biostatistics does not appear to alter these results.

The clinical and economic consequences of nosocomial central venous catheter-related infection: are antimicrobial catheters useful?

Central venous catheters (CVCs) are essential for many hospitalized patients, but they are associated with important infectious complications. Recent studies have indicated that CVCs coated with antimicrobial agents reduce the incidence of catheter-related bloodstream infection (CR BSI). To estimate the clinical and economic consequences of short-term central venous catheter-related infection and the potential usefulness of antimicrobial-coated catheters, we reviewed and synthesized the available relevant literature. Statistical pooling was used to estimate the incidence of both catheter colonization and CR BSI. The attributable mortality of CR BSI was also evaluated. In addition, the economic consequences of both local and systemic catheter-related infection was estimated from literature reports that used micro-costing and other techniques. Among patients in whom standard, noncoated CVCs are in place for an average of 8 days, 24.7% are expected to develop catheter colonization (95% confidence interval [CI(95)], 22.0%-27.5%). Approximately 5.2% (CI(95), 3.9%-6.5%) will develop CR BSI. The attributable mortality of CR BSI remains unclear, but recent studies are consistent with a range from 4% to 20%. An episode of local catheter-related infection leads to an additional cost of approximately $400, whereas the additional cost of CR BSI ranges from approximately $6,005 to $9,738. Formal economic analyses indicate that CVCs coated with antibacterial agents (such as chlorhexidine-silver sulfadiazine or minocycline-rifampin) likely reduce infectious complications, yielding economic advantages. In light of the substantial clinical and economic burden of catheter-related infection, hospital personnel should adopt proven cost-effective methods to reduce this common and important nosocomial complication.

Clinical and economic effects of pulmonary artery catheterization in nonemergent coronary artery bypass graft surgery

OBJECTIVE

To examine the association between use of pulmonary artery catheterization with hospital outcomes and costs in nonemergent coronary artery bypass graft (CABG) surgery.

DESIGN

Retrospective cohort study.

SETTING

Fifty-six community-based hospitals in 26 states.

PARTICIPANTS

A total of 13,907 patients undergoing nonemergent CABG surgery between January 1, 1997, and December 31, 1997.

MEASUREMENTS AND MAIN RESULTS

Discharge abstracts for each patient were examined. Stratified and multivariate analyses were used to assess the impact of pulmonary artery catheters (PACs) on in-hospital mortality, length of stay in the intensive care unit, total length of stay, and hospital costs. Outcomes were adjusted for patient demographic factors, hospital characteristics, and hospital volume of PAC use in the year of analysis. Fifty-eight percent of the patients received a PAC. After adjustment, the relative risk of in-hospital mortality was 2.10 for the PAC group compared with the patients who did not receive a PAC (95% confidence interval [CI], 1.40 to 3.14; p < 0.001). The mortality risk was significantly higher in hospitals with the lowest third of PAC use (odds ratio, 3.35; 95% CI, 1.74 to 6.47; p < 0.001) and not significantly increased in the highest two thirds of users (odds ratio, 1.62; 95% CI, 0.99 to 2.66; p = 0.09). Days spent in critical care were similar; however, total length of hospital stay was 0.26 days longer in the PAC group (p < 0.001). Hospital costs were $1,402 higher in the PAC group.

CONCLUSION

In the setting of nonemergent CABG surgery, pulmonary artery catheterization was associated with an increased risk of in-hospital mortality, greater length of stay, and higher total costs, particularly in hospitals with low volume of PAC use.

Clinical and economic consequences of nosocomial catheter-related bacteriuria

Indwelling catheters are strongly associated with the development of bacteriuria, which can lead to significant morbidity in hospitalized patients. This report, a review of the literature, evaluates the infectious outcomes of patients with indwelling catheters to determine the precise clinical and economic impact of catheter-related infection. Statistical pooling was used to estimate the incidence of bacteriuria in hospitalized patients with indwelling catheters. In addition, the proportion of patients with catheter-related bacteriuria in whom symptomatic urinary tract infection and bacteremia will develop was estimated through quantitative synthesis of previous reports. Costs were estimated by using microcosting techniques. Of patients who have indwelling catheters for 2 to 10 days, bacteriuria is expected to develop in 26% (95% confidence interval [CI], 23% to 29%). Among patients with bacteriuria symptoms of urinary tract infection will develop in 24%, (95% CI, 16% to 32%), and bacteremia from a urinary tract source will develop in 3.6% (95% CI, 3.4% to 3.8%). Each episode of symptomatic urinary tract infection is expected to cost an additional $676, and catheter-related bacteremia is likely to cost at least $2836. Given the clinical and economic burden of urinary catheter-related infection, infection control professionals and hospital epidemiologists should use the latest infection control principles and technology to reduce this common complication.

Is hospitalism new? An analysis of medicare data from Washington State in 1994

CONTEXT

Managed care, increased disease severity, and more complex treatment options may be reasons for the recent enthusiasm for "hospitalists"--physicians who specialize in the care of inpatients. It is not clear, however, whether hospitalism is a new model for caring for inpatients or merely a new description for previously existing practice patterns. PRACTICE PATTERNS EXAMINED: The proportion of physician visits occurring in the hospital before the introduction of the term hospitalists. Five specialties were examined: family/general practice, general internal medicine, cardiology, gastroenterology, and pulmonology.

DATA SOURCE

1994 Medicare Part B claims data for beneficiaries 65 years of age and older who received all of their care in Washington State.

RESULTS

For the average family/general practitioner, 10% of all Medicare visits occurred in the hospital. Corresponding figures for the other specialties were 20% for general internists, 36% for cardiologists, 38% for gastroenterologists, and 45% for pulmonologists. A substantial number of physicians devoted most of their Medicare effort to inpatient care (i.e., hospital visits > 50% of total visits). If this definition were used as a proxy for hospitalism, 4% of family/general practitioners, 10% of general internists, 20% of gastroenterologists, 29% of cardiologists, and 37% of pulmonologists would have been considered hospitalists in Washington State during 1994. On the other hand, 35% of family/general practitioners, 18% of general internists, 7% of both gastroenterologists and pulmonologists, and 4% of cardiologists did not bill Medicare for any inpatient visits and could reasonably be categorized as "officists."

CONCLUSION

Physicians vary considerably in the proportion of their workload that occurs in the hospital or outpatient setting. Even before the term was coined, a considerable number of physicians were de facto "hospitalists."

Urinary catheters: what type do men and their nurses prefer?

OBJECTIVES

Urinary catheters are used frequently, but the relative risks and benefits of different types of devices are not clear. We sought to determine the beliefs of both older male patients and nursing staff about the relative merits and problems of condom and indwelling catheters.

DESIGN

Patient and nurse survey using convenience sampling.

SETTING

A University-affiliated Veterans Affairs medical center.

PARTICIPANTS

Men hospitalized on medical, rehabilitation and nursing home units using either an indwelling or a condom catheter were invited to participate as were all members of the nursing staff on these units. Of 116 eligible patients, 104 were interviewed (response rate = 90%). Of 107 eligible nursing staff members, 99 completed the questionnaires (response rate = 92%).

INTERVENTION AND MEASUREMENTS

Consenting patients were interviewed personally about their urinary catheter. The nursing staff were asked to complete a self-administered questionnaire.

RESULTS

Patients were mostly older and predominantly hospitalized on the medical service. Compared with those using an indwelling catheter, patients using a condom catheter were more likely to believe that their catheter was comfortable (86 vs 58%, P = .04) and less likely to believe it was painful (14 vs 48%, P = .008) or to restrict their activity (24 vs 61%, P = .002). The nursing staff had a mean of 13 years nursing experience, and the majority worked in the nursing home unit. Most of the nursing staff respondents believed that condom catheters were less painful and restrictive for patients and were easier to apply, but they also believed that they fell off and leaked more often and required more nursing time.

CONCLUSIONS

Both patients and nursing staff prefer condom to indwelling catheters for patient comfort, but they recognize that dislodgment and leaking are major drawbacks of condom catheters. A more secure condom catheter would greatly improve the management of male incontinence.

Cost-effectiveness of antiseptic-impregnated central venous catheters for the prevention of catheter-related bloodstream infection

CONTEXT

A recent randomized controlled trial and meta-analysis indicated that central venous catheters impregnated with an antiseptic combination of chlorhexidine and silver sulfadiazine are efficacious in reducing the incidence of catheter-related bloodstream infection (CR-BSI); however, the ultimate clinical and economic consequences of their use have not been formally evaluated.

OBJECTIVE

To estimate the incremental clinical and economic outcomes associated with the use of antiseptic-impregnated vs standard catheters.

DESIGN

Decision analytic model using data from randomized controlled trials, meta-analyses, and case-control studies, as well as safety data from the US Food and Drug Administration.

SETTING AND PATIENTS

A hypothetical cohort of hospitalized patients at high risk for catheter-related infections (eg, patients in intensive care units, immunosuppressed patients, and patients receiving total parenteral nutrition) requiring use of a central venous catheter.

INTERVENTION

Short-term use (2-10 days) of chlorhexidine-silver sulfadiazine-impregnated multilumen central venous catheters and nonimpregnated catheters.

MAIN OUTCOME MEASURES

Expected incidence of CR-BSI and death attributable to antiseptic-impregnated and standard catheter use; direct medical costs for both types of catheters.

RESULTS

In the base-case analysis, use of antiseptic-impregnated catheters resulted in a decrease in the incidence of CR-BSI of 2.2% (5.2% for standard vs 3.0% for antiseptic-impregnated catheters), a decrease in the incidence of death of 0.33% (0.78% for standard vs 0.45% for antiseptic-impregnated), and a decrease in costs of $196 per catheter used ($532 for standard vs $336 for antiseptic-impregnated). The decrease in CR-BSI ranged from 1.2% to 3.4%, the decrease in death ranged from 0.09% to 0.78%, and the costs saved ranged from $68 to $391 in a multivariate sensitivity analysis.

CONCLUSION

Our analyses suggest that use of chlorhexidine-silver sulfadiazine-impregnated central venous catheters in patients at high risk for catheter-related infections reduces the incidence of CR-BSI and death and provides significant saving in costs. Use of these catheters should be considered as part of a comprehensive nosocomial infection control program.

Antibiotics in acute bronchitis: a meta-analysis

PURPOSE

Most patients with acute bronchitis who seek medical care are treated with antibiotics, although the effectiveness of this intervention is uncertain. We performed a meta-analysis of randomized, controlled trials to estimate the effectiveness of antibiotics in the treatment of acute bronchitis.

SUBJECTS AND METHODS

English-language studies published January 1966 to April 1998 were retrieved using MEDLINE, bibliographies, and consultation with experts. Only randomized trials that enrolled otherwise healthy patients with a diagnosis of acute bronchitis, used an antibiotic in the treatment group and a placebo in the control group, and provided sufficient data to calculate an effect size were included.

RESULTS

We identified eight randomized controlled trials that satisfied all inclusion criteria. These studies used one of three antibiotics (erythromycin, doxycycline, trimethoprim/sulfamethoxazole). The use of antibiotics decreased the duration of cough and sputum production by approximately one-half day (summary effect size 0.21; 95% CI, 0.05 to 0.36). For specific symptoms, there were nonsignificant trends favoring the use of antibiotics: a decrease of 0.4 days of purulent sputum (95% CI, -0.1 to 0.8), a decrease of 0.5 days of cough (95% CI, -0.1 to 1.1), and a decrease of 0.3 days lost from work (95% CI, -0.6 to 1.1).

CONCLUSION

This meta-analysis suggests a small benefit from the use of the antibiotics erythromycin, doxycycline, or trimethoprim/sulfamethoxazole in the treatment of acute bronchitis in otherwise healthy patients. As this small benefit must be weighed against the risk of side effects and the societal cost of increasing antibiotic resistance, we believe that the use of antibiotics is not justified in these patients.

The effectiveness of a clinical practice guideline for the management of presumed uncomplicated urinary tract infection in women

PURPOSE

Acute uncomplicated urinary tract infection is a common and costly disorder in women. To reduce potentially unnecessary expense and inconvenience, a large staff-model health maintenance organization instituted a telephone-based clinical practice guideline for managing presumed cystitis in which women 18 to 55 years of age who met specific criteria were managed without a clinic visit or laboratory testing. We sought to evaluate the effects of the guideline.

SUBJECTS AND METHODS

We performed a population-based, before-and-after study with concurrent control groups at 24 primary care clinics to assess the effect of guideline implementation on resource utilization and on the occurrence of potential adverse outcomes. We measured the proportion of patients with presumed uncomplicated cystitis who had a return office visit for cystitis or sexually transmitted disease or who developed pyelonephritis within 60 days of the initial diagnosis. Relative risks (RR) and 95% confidence intervals (CI) were estimated, adjusting for the effects of clustering within clinics.

RESULTS

A total of 3,889 eligible patients with presumed acute uncomplicated cystitis were evaluated. As compared with baseline, guideline implementation significantly decreased the proportion of patients with presumed cystitis who received urinalysis (RR = 0.75; CI, 0.70 to 0.80), urine culture (RR = 0.73; CI, 0.68 to 0.79), and an initial office visit (RR = 0.67; CI, 0.62 to 0.73), while increasing the proportion who received a guideline-recommended antibiotic 2.9-fold (CI, 2.4 to 3.7-fold). In the prospective comparison of the 22 intervention and two control clinics, the guideline decreased the proportion of patients who had urinalyses performed (RR = 0.80; CI, 0.65 to 0.98) and increased the proportion of patients who were prescribed a guideline-recommended antibiotic (RR = 1.53; CI, 1.01 to 2.33). Adverse outcomes did not increase significantly in either comparison.

CONCLUSION

Guideline use decreased laboratory utilization and overall costs while maintaining or improving the quality of care for patients who were presumptively treated for acute uncomplicated cystitis.

Preventing catheter-related bacteriuria: should we? Can we? How?

Up to 25% of hospitalized patients undergo urinary catheterization, and about 5% develop bacteriuria each day of catheterization. Catheter-related bacteriuria is associated with increased morbidity and mortality. We performed an evidence-based synthesis of the literature on preventing catheter-associated urinary tract infections (UTIs) to develop recommendations for clinicians. Catheterization should be avoided when not required and when needed, should be terminated as soon as possible. Use of suprapubic and condom catheters may be associated with a lower risk of UTI than use of urethral catheters. Aseptic catheter insertion and a properly maintained closed drainage system are crucial to reducing the risk of bacteriuria. Instillation of antimicrobial agents into the bladder or urinary drainage bag and rigorous meatal cleansing seem to be of little benefit. Use of urinary catheters coated with silver alloy may reduce the risk of UTI. Systemic antimicrobial drug therapy seems to prevent UTIs, but primarily for patients catheterized for 3 to 14 days. Antibiotic drug prophylaxis is especially valuable in patients undergoing transurethral resection of the prostate or renal transplantation. Using these methods, urinary catheter-associated UTI can often be prevented for weeks, but not longer terms.