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Examines the risks of thromboembolism in various forms of valvular heart disease. Assessment of the risk of bleeding; Role of antiplatelet drugs in prosthetic valve endocarditis; Effects of oral anticoagulants on patients with atherosclerosis of the aorta.

Objective: To examine the cost-effectiveness of approaches to the diagnosis and treatment of patients with type II (non-insulin-dependent) diabetes mellitus (NIDDM) who have foot infections and suspected osteomyelitis.Design: Decision and cost-effectiveness analyses were performed using a Markov model. We examined the prevalence of osteomyelitis, the major complications and efficacies of long-term antibiotic therapy and surgery, and the performance characteristics of four diagnostic tests (roentgenography, technetium Tc 99m bone scanning, indium in 111-labeled white blood cell scanning, and magnetic resonance imaging). Data were drawn from the English-language literature using MEDLINE searches and bibliographies from selected articles.Setting: Primary care.Patients: Patients with NIDDM who had foot infections and suspected osteomyelitis but no signs of systemic toxicity.Interventions: Following hospitalization for surgical débridement and intravenous antibiotic therapy: (1) treatment for presumed soft-tissue infection, (2) culture-guided empiric treatment for presumed osteomyelitis, (3) 71 combinations of diagnostic tests preceding antibiotic therapy for osteomyelitis, (4) 71 combinations of tests preceding amputation, and (5) immediate amputation.Main Outcome Measures: Quality-adjusted life expectancy, average costs.Results: Culture-guided empiric treatment for osteomyelitis with 10 weeks of oral antibiotic therapy has similar effectiveness to testing followed by a long course of antibiotic therapy if any test result is positive. However, empiric treatment is the least expensive strategy.Conclusions: Noninvasive testing adds significant expense to the treatment of patients with NIDDM in whom pedal osteomyelitis is suspected, and such testing may result in little improvement in health outcomes. In patients without systemic toxicity, a 10-week course of culture-guided oral antibiotic therapy following surgical débridement may be as effective as and less costly than other approaches. [ABSTRACT FROM AUTHOR]

Objective: To determine the clinical and economic effects of screening for prostate cancer with prostate-specific antigen (PSA), transrectal ultrasound (TRUS), and digital rectal examination (DRE).Design: Decision analytic cost-utility analysis comparing four screening strategies with a strategy of not screening. We assumed that the cancer detection rate and stage distribution were predicted by each combination of tests and that localized cancer was treated with radical prostatectomy. For each strategy, we calculated life expectancy, quality-adjusted life expectancy (QALE), and cost-utility ratios for unselected and high-prevalence populations.Data: Probabilities and rates for clinical events were gathered from published data. We assessed utilities by the time-trade-off method using urologists, radiation oncologists, and internists as subjects. The Clinical Cost Manager at the New England Medical Center provided cost data.Results: In unselected men between the ages of 50 and 70 years, screening with PSA or TRUS prolonged unadjusted life expectancy but diminished QALE. Screening with DRE alone yielded no reduction in mortality at any age. All programs increased costs. Results were sensitive only to assumptions about the efficacy of treatment. In high-prevalence populations, screening produced a similar pattern: gains in unadjusted life expectancy, losses in QALE, and increased costs.Conclusions: Our analysis does not support using PSA, TRUS, or DRE to screen asymptomatic men for prostatic cancer. Screening may result in poorer health outcomes and will increase costs dramatically. Assessment of comorbidity, risk attitude, and valuation of sexual function may identify individuals who will benefit from screening, but selecting high-prevalence populations will not improve the benefit of screening. [ABSTRACT FROM AUTHOR]

Objectives: --To determine the extent to which interinstitutional variations in length of stay are explained by differences in patient characteristics and to determine whether patients in hospitals with shorter lengths of stay had worse outcomes.Design: --We reviewed patients' medical records and surveyed patients between 3 and 12 months after hospital discharge using a questionnaire.Setting: --Six teaching hospitals in California and Massachusetts.Patients: --A cohort of 2484 selected patients who had been hospitalized for acute myocardial infarction or to rule out acute myocardial infarction, coronary artery bypass graft surgery, total hip replacement, cholecystectomy, or transurethral prostatectomy. Between 73% and 84% of the patients with each condition completed a follow-up questionnaire.Outcome Measures: --In-hospital complications, deaths, length of stay, functional status after hospital discharge, readmission, and patient satisfaction with hospital care were analyzed.Results: --Significant interinstitutional differences in length of stay were noted for all conditions except rule-out acute myocardial infarction. Statistical adjustment for case-mix differences accounted for most of the interinstitutional differences in length of stay for total hip replacement but explained little of the differences in the other conditions. When we controlled statistically for other predictors, length of stay did not have a significant impact on deaths, functional status after hospital discharge, the probability of readmission, or patient satisfaction with hospital care.Conclusion: --More research is needed to determine the medical practices that are related to variations in lengths of stay. Routinely available outcome data may help preserve quality in the face of efforts to decrease costs by effecting more standardized practices of care. [ABSTRACT FROM AUTHOR]

Hospitalizations for patients with prosthetic heart valves undergoing noncardiac surgery are frequently prolonged for intravenous heparin therapy to decrease the incidence of thromboembolism while patients are not taking oral anticoagulant agents. Because the rate of thromboembolic events is quite low and the period of increased risk is very short, the cost of preventing these rare events can be great. We performed cost-effectiveness analyses addressing these issues. We calculated the marginal cost per additional quality-adjusted year of life gained per thromboembolic event averted and per death averted. We conclude that the marginal cost of prolonging hospitalization to administer heparin is prohibitively high compared with most contemporary therapies, except when the patient has the most thrombogenic of valves. We also discuss the ethical and legal ramifications of integrating the results of cost-effectiveness analyses into clinical practice. [ABSTRACT FROM AUTHOR]

Objective: To determine how physicians weigh iatrogenic complications when making clinical decisions.Design: Physicians were mailed a questionnaire describing two simplified scenarios--one involving a patient with a cerebral embolism and the other involving a patient with a life-threatening arrhythmia. In each scenario there was one potential natural adverse outcome (which could be prevented with drug therapy) and one potential drug side effect (iatrogenic adverse outcome), which would be clinically indistinguishable from the natural adverse outcome. Half the respondents were given the probability of the natural adverse outcome (PN) and were asked to specify the probability of the iatrogenic adverse outcome (PI) at which they felt that giving and withholding the therapy were equivalent strategies. The other respondents were given the PI and asked to specify the PN at which they felt the two strategies were equivalent.Setting: Academic medical center.Participants: Staff physicians.Measurements and Main Results: Results are expressed as the ratio PI/PN at which the respondent felt that giving and not giving therapy were equivalent strategies. A ratio less than 1 indicates that errors of commission (iatrogenic adverse outcomes) were given more weight than were errors of omission (natural adverse outcomes when therapy was withheld). Ratios less than 1 were provided in 56% of the responses (n = 230). The mean PI/PN in the group with ratios less than 1 was 0.53 +/- 0.26 (SD; n = 129).Conclusions: In making decisions, some physicians appear to weigh errors of commission more heavily than they do errors of omission, while others weigh them equally. This diversity of physicians' attitudes may explain some of the variation observed in clinical practice in settings where The possibility of iatrogenic complications is of concern. [ABSTRACT FROM AUTHOR]

Variability in length of stay (LOS) and its determinants were studied in 60 patients without complications after acute myocardial infarction (AMI) at three teaching hospitals. The patients at the three hospitals had similar clinical presentations and in-hospital courses. However, 81% of patients admitted to the intensive care unit (ICU) at one hospital were transferred to lower levels of care within 48 hours, compared with 40% and 56% at the other two hospitals (p less than 0.05). Patients who underwent pre-discharge exercise tests (ETT) had a longer total LOS than patients who did not (11.9 +/- 4.3 vs 9.2 +/- 2.9 days; p less than 0.01). Similarly, patients who underwent 24-hour ambulatory monitoring (AMB-MON) had a longer total LOS than patients who did not (12.3 +/- 4.3 vs 9.1 +/- 2.8 days; p less than 0.001). No differences in clinical characteristics or in survival at six months were detected between patients who did and did not undergo ETT or AMB-MON. Total LOS correlated with whether patients underwent 0, 1, or both of these tests (p less than 0.0001); each test was associated with a 2.3-day increase in the duration of hospitalization. The authors conclude that such tests may prolong total LOS of patients without complications after AMI. [ABSTRACT FROM AUTHOR]

Context: Chronic hepatitis C (CHC) infection affects nearly 4 million people in the United States. Treatment with interferon alfa-2b has been limited by its cost and low likelihood of long-term response.Objective: To examine the cost-effectiveness of alternative pretreatment management strategies for patients with CHC.Design: Decision and cost-effectiveness analysis using a Markov model to examine prevalence of genotypes, viral load, and histological characteristics in relation to the sustained response rate with treatment. Data were based on a previously published decision model and a MEDLINE literature search for hepatitis C, biopsy, and liver from 1966 to 1996.Patients: A hypothetical population of patients with CHC infection and elevated serum alanine aminotransferase level.Interventions: Combinations of liver biopsy, genotyping, and quantitative viral load determination prior to a single 6-month course of interferon alfa-2b; empirical interferon treatment; and conservative management.Main Outcome Measures: Proportion of sustained responders, lifetime costs, life expectancy, and quality-adjusted life expectancy.Results: Strategies involving hepatitis C virus (HCV) RNA testing had marginal cost-effectiveness ratios up to $4400 per discounted quality-adjusted life-year gained but would miss up to 36% of sustained responders. Empirical interferon treatment had a marginal cost-effectiveness ratio of $12400 per discounted quality-adjusted life-year gained and reached all potential sustained responders. Strategies involving liver biopsy were more expensive and would miss 6% of sustained responders and yield slightly lower life expectancies.Conclusions: Routine liver biopsy before treatment with interferon increases the cost of managing patients with CHC without improving health outcomes. Using quantitative HCV RNA testing to guide therapy misses some potential sustained responders. Empirical interferon treatment has a marginal cost-effectiveness ratio within the bounds of other commonly accepted therapies and misses none of the sustained responders. [ABSTRACT FROM AUTHOR]

Purpose: To review the usefulness of angioplasty done early in the course of an acute myocardial infarction without preceding thrombolytic therapy.Data Sources: The English-language literature was searched from 1983 through October 1991 using MEDLINE; bibliographies from selected articles were searched by hand.Study Selection: Series reporting results for direct angioplasty without preceding thrombolytic therapy were reviewed. Twenty-three articles describing a total of 4368 patients were found.Data Extraction: After duplicate patient series were eliminated, weighted average short- and long-term mortality rates were calculated for the remaining 2073 patients in 10 series and for selected clinical subsets.Results Of Data Synthesis: Average hospital mortality for patients with acute myocardial infarction having direct angioplasty was 8.3% (95% Cl, 7.1% to 9.5%). Patients in cardiogenic shock had the highest mortality (44.2%; Cl, 35.9% to 52.5%); patients with one-vessel disease had the lowest (1%; Cl, 0% to 2.3%). For patients in cardiogenic shock, data on direct angioplasty appeared superior to data for similar patients receiving thrombolytic therapy. Although few data exist, a survival advantage was also suggested for patients with a history of previous bypass surgery (hospital mortality, 11.1% [Cl, 4.4% to 17.8%]).Conclusions: Direct angioplasty has an overall mortality similar to that of thrombolytic therapy. Patients who may benefit more from mechanical revascularization than from thrombolytic therapy include those at increased risk for thrombolytic therapy (uncontrolled hypertension, recent major surgery, cerebrovascular accident, prolonged cardiopulmonary resuscitation, or bleeding diathesis), and those with cardiogenic shock. The efficacy in several other patient subsets (age greater than 65 years, previous coronary artery bypass grafting, prolonged delay before reperfusion) warrants further study. [ABSTRACT FROM AUTHOR]

No prospective, randomized clinical trial comparing coronary artery bypass grafting, percutaneous transluminal coronary angioplasty, and conservative therapy has been reported. To address when revascularization is indicated, we constructed a decision analytic model. Our model incorporates procedure-related mortality and morbidity, coronary artery disease-related mortality, and the benefit of revascularization. We determined the quality-adjusted life expectancy and expected costs for each strategy. Our model suggests that angioplasty is a reasonable alternative to bypass surgery in patients with favorable lesions if angioplasty would provide a comparable degree of revascularization. Our model predicts that patients treated with angioplasty will have more revascularization procedures than will patients treated with bypass surgery but predicts that both treatments will cost the same over the typical patient's lifetime. In many patients with severe angina or documented ischemia, angioplasty is indicated for stenosis of a single artery. In patients with two vessel disease that is amenable to angioplasty, angioplasty may be a reasonable alternative to bypass surgery. Even in patients whose three vessel disease can be completely revascularized by angioplasty, bypass surgery, although relatively expensive, is slightly better than angioplasty. In patients with three vessel disease and comorbidities that increase operative risk, angioplasty may be a reasonable alternative to either bypass surgery or medical therapy. [ABSTRACT FROM AUTHOR]

We used decision analysis to compare the conventional strategy of biopsy-tailored therapy with alternative strategies not using renal biopsy in treating adults with idiopathic nephrotic syndrome. We evaluated data on steroid and platelet-inhibitor therapies and a new clinical strategy, empiric sequential therapy. This sequential approach involves use of short-term alternate-day steroid agents, followed by long-term platelet inhibitors for persistent nephrotic syndrome. Our results indicate that, contrary to usual practice, use of renal biopsy is not necessary in caring for adult patients with idiopathic nephrotic syndrome; empiric short-term alternate-day steroid therapy is equally efficacious. If the benefits of platelet-inhibitor therapy for treating membranoproliferative glomerulonephritis are confirmed, empiric sequential therapy also will be equally efficacious. Our study shows how decision analysis can be used to identify superfluous diagnostic procedures. [ABSTRACT FROM AUTHOR]

The availability of vidarabine for the therapy of suspected herpes simplex encephalitis presents a difficult decision for a physician as to whether to do brain biopsy, to treat blindly, or to withhold specific therapy in a patient. The choice is made more difficult because the physician must weigh four likelihoods simultaneously: namely, of the disease, of a life-threatening complication from biopsy, of a beneificial effect from vidarabine, and of a serious adverse effect from the drug. Using decision analysis, we have derived a series of threshold probabilities whereby the physician can select his own estimates of these likelihoods to arrive at a rational approach to management. When reasonable assessments are made of the risks of biopsy and of vidarabine therapy, brain biopsy is likely to be the optimal approach in the majority of patients suspected of having herpes simplex encephalitis. [ABSTRACT FROM AUTHOR]

The choice between coronary by-pass surgery and medical therapy in patients with angiographically documented coronary artery disease was examined. This decision analysis included consideration of patient preferences, severity of disease, prognosis with medical therapy, surgical mortality rate, graft patency rate, the probability that surgery will provide both short-term and long-term pain relief, and the probability that surgery will alter long-term survival. Coronary surgery was found to be the preferred therapy in many patients with disabling angina; it was rarely found to be the preferred therapy in asymptomatic patients, even those with proximal obstruction of the left anterior descending coronary artery. The therapeutic decision was strongly affected by differences in patient attitudes and differences in the past results of the prospective surgeon. This paper presents both a data base and a methodology that allow the physician to apply decision analysis to individual patients with coronary artery disease. [ABSTRACT FROM AUTHOR]

Objective: To estimate the cost-effectiveness of interferon-alpha 2B for the treatment of patients with chronic hepatitis B infection who are positive for hepatitis B e antigen (HBeAg).Design: Meta-analysis of nine randomized controlled trials and cost-effectiveness analysis, projecting the clinical and economic outcomes expected from changes in serologic markers of hepatitis B viral replication.Data Sources: MEDLINE search, expert panel opinion, hospital cost data, and adjusted physician charges.Patients: 552 patients with confirmed chronic hepatitis B infection who were positive for HBeAg.Intervention: Interferon-alpha 2b.Measurements: Lifetime incidence of cirrhosis and hepatocellular carcinoma; life expectancy; quality-adjusted life expectancy; and costs and marginal cost-effectiveness ratios from a societal perspective.Results: Interferon-alpha 2b increases the likelihood of becoming negative for HBeAg from 9.1% to 45.6% (difference, 36.5%; 95% CI, 23.7% to 49.2%) and of becoming negative for hepatitis B surface antigen from 1.7% to 7.7% (difference, 6.0%; CI, 2.8% to 9.3%) in the first year. For a 35-year-old person with chronic hepatitis B who is HBeAg positive, our analysis suggests that interferon-alpha 2b will increase life expectancy by 3.1 years or 3.4 quality-adjusted life-years and will decrease projected lifetime costs, even if future savings are discounted; thus, interferon-alpha 2b is the dominant strategy. Even with the model biased strongly in favor of standard care, the marginal cost-effectiveness ratio of interferon did not exceed $12,000 per life-year gained.Conclusions: Interferon-alpha 2b should prolong life and lower costs for patients with chronic hepatitis B who are HBeAg positive. [ABSTRACT FROM AUTHOR]

Editorial. Discusses E. Catherwood and colleagues' study on the cost-effectiveness of cardioversion and antiarrhythmic therapy in nonvalvular atrial fibrillation. Importance of cardioversion as the first-line therapy; Stratification of the risk for embolic stroke in patients; Proarrythmic effects of quinidine; Failure to recommend amiodarone during initial stage of therapy.

Editorial. Comments on medical screening for pre-clinical diseases. Benefits of medical screening; Medical screening for ovarian cancer; Recommendations regarding medical screening for ovarian cancer.

The exact mechanisms by which Helicobacter pylori infection results in gastric mucosal injury are unclear. However, it has been demonstrated that surface protein extracts of the bacterium can induce a number of disturbances within the rat gastric mucosal microcirculation, including platelet aggregation and macromolecular leakage (MML) of labeled albumin. This study aimed to determine the mechanisms involved in inducing these events using the technique of fluorescent in vivo microscopy. Male Wistar rats were pretreated with either ketotifen, a mast cell stabilizer (1 mg/kg), pyrilamine, an H1-receptor antagonist (30 mg/kg), hexanolamine-PAF, a PAF-receptor antagonist (10 microg/kg), L-arginine, the nitric oxide precursor (300 mg/kg) or vehicle, saline. Then 0.5 ml of H. pylori extract was administered to the exteriorized gastric mucosa of the anesthetized rat. Alterations in fluorescein-labeled albumin leak, vessel diameters, and acridine red-labeled leukocyte and platelet activity were determined over a 2-hr period. Saline pretreated animals demonstrated significant MML with a peak at 5 min (11%, P<0.02). This was prevented with ketotifen and pyrilamine, but not with hexanolamine-PAF (17.5%, P<0.05) and L-arginine (13%, P<0.05). Significant numbers of platelet emboli and thrombi were observed within mucosal capillaries and postcapillary venules with vehicle pretreatment; this was prevented with hexanolamine-PAF and L-arginine, but not with ketotifen and pyrilamine. In conclusion, these studies demonstrate that more than one mediator is involved in inducing the rat gastric mucosal microcirculatory disturbances associated with H. pylori administration. Mast cells and histamine are linked to MML, with PAF, probably not derived from mast cells, involved in platelet activation. [ABSTRACT FROM AUTHOR]

Looks at how the issue of a patient's age should impact the decision of whether or not to do valve replacement surgery on a patient with symptomatic aortic stenosis. Development of a model to compare the risks and benefits of aortic-valve replacement and myocardial revascularization in the elderly with those of medical therapy; Details.

Objective: Initial therapy with ribavirin and interferon alpha-2b results in a higher sustained virological response than interferon alone, but this regimen is expensive. We aimed to examine the cost-effectiveness of 24- or 48-wk initial treatment with combination therapy versus interferon alone for patients who have chronic hepatitis C., Methods: Data from recent randomized clinical trials comparing combination therapy to interferon alone were applied to a previously published computer cohort simulation to project lifelong clinical and economic outcomes. Natural history and economic estimates were based on published literature, expert panel estimates, and actual variable cost and reimbursement data., Results: Using treatment stopping rules, sustained viral negative response rates would be 33.1% and 39.8% for patients receiving 24 versus 48 wk of ribavirin/interferon, compared with 14.3% for 48 wk of interferon alone. Compared to the interferon alone strategy, 24 or 48 wk of combination therapy should prolong life expectancy by 1.4 to 2.0 yr at marginal cost-effectiveness ratios of $4,400 to $5,400 per discounted quality-adjusted life-year (DQALY) gained. Compared to 24 wk of combination therapy, 48 wk of combination therapy should prolong life expectancy by 0.6 yr at a marginal cost-effectiveness ratio of $7,700 per DQALY gained. The results were robust, with 24 or 48 wk of combination therapy remaining preferred and cost-effective in sensitivity analysis compared with interferon alone., Conclusion: For patients with chronic hepatitis C, 24 or 48 wk of ribavirin and interferon should prolong life and be cost-effective when compared with 48 wk, of interferon alone.