Clinical problem-solving. Of nicks and time.
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Adult↗
Biomedical subjects
S Saint
Publications and source records attributed to S Saint.
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.
Coronary Disease↗
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.
Acute Disease↗
Electron beam computed tomography in the diagnosis of obstructive coronary artery disease.
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Coronary Disease↗
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.
Bacterial Proteins↗
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.
Adult↗
Where have all the hours gone?
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California↗
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.
Acute Disease↗
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.
Aged↗
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.
Alloys↗
Clinical problem-solving. Impatient inpatient care.
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Adrenal Cortex Hormones↗
Case of the month
Each month, we will present a challenging Case of the Month for The Green Journal readers, who must use their clinical acumen to arrive at the correct answer. We will also post the case each month on the Journal's web site (http://www.elsevier.com/locate/ajmselect). Several possible answers may be consistent with the case presentation; use your best judgment. Please send your answer (one per respondent) and indicate the case to which you are responding to The Green Journal at editors@amjmed.org or via FAX to (415) 447-2799. Only those answers with a complete mailing address will be considered. The correct answer will appear in the August issue of the Journal. The first five persons who submit correct answers will receive a free one-year subscription to the Journal. Colleagues of Dr. Hirsch in Ann Arbor, Michigan, are not eligible for this month's case. If you would like to contribute a case, please submit a brief synopsis (<250 words) to the editorial office. An individual may win only once per calendar year.
Journal Article↗
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.
Bacteriuria↗
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.
Adult↗
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.
Bias↗
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.
Adult↗
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.
Adult↗
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.
Anti-Infective Agents↗