PubMed Health⌕ Search

Biomedical subjects

K Schulman

Publications and source records attributed to K Schulman.

16 recordsLinked to original sources
PubMed2000

The association between institutional primary angioplasty procedure volume and outcome in elderly Americans.

BACKGROUND: The association between greater procedure volume and improved patient outcome in cardiac procedures has been established in percutaneous transluminal coronary angioplasty (PTCA), coronary stent placement and coronary bypass surgery. The association between primary angioplasty volume and outcome has not been evaluated. METHODS: We evaluated the association between the volume of primary angioplasty procedures with short- and long-term outcome in 6,124 patients with documented acute myocardial infarction. Patients without shock on presentation treated with primary coronary angioplasty within 12 hours of hospital admission were selected from consecutive infarct patients included in the Cooperative Cardiovascular Project database. Patients were divided into quartiles based on the volume of primary PTCA procedures performed at their admitting hospital. RESULTS: The majority of United States (US) hospitals performed less than three primary PTCA procedures per month. Patients admitted to hospitals in the lowest volume quartile of primary PTCA had 31% higher 30-day mortality than those admitted to the highest volume quartile. After adjustment for baseline differences in patient characteristics, there was an association between admission to higher volume primary PTCA hospitals and lower 30-day mortality (odds ratio per volume quartile = 0.91; 95% confidence interval = 0.83-0.99). CONCLUSION: Eighty-two percent of US hospitals perform less than three primary PTCA procedures per month. In elderly Americans treated with primary PTCA, we observed an association between admission to higher volume hospitals and lower short- and long-term mortality. This association was independent of total PTCA volumes.

Aged↗
PubMed1998

Estimating country-specific cost-effectiveness from multinational clinical trials.

Because costs and outcomes of medical treatments may vary from country to country in important ways, decision makers are increasingly interested in having data based on their own country's health care situations. This paper proposes methods for estimating country-specific cost-effectiveness ratios from data available from multinational clinical trials. It examines how clinical and economic outcomes interact when estimating treatment effects on cost and proposes empirical methods for capturing these interactions and incorporating them when making country-specific estimates. We use data from a multinational phase III trial of tirilazad mesylate for the treatment of subarachnoid haemorrhage to illustrate these methods. Our findings suggest that it is possible for meaningful country-by-country differences to be found in such trial data. These differences can be useful in informing reimbursement, utilization, and other decisions taken at the country level.

Clinical Trials as Topic↗
PubMed1998

Resource costing for multinational neurologic clinical trials: methods and results.

We present the results of a multinational resource costing study for a prospective economic evaluation of a new medical technology for treatment of subarachnoid hemorrhage within a clinical trial. The study describes a framework for the collection and analysis of international resource cost data that can contribute to a consistent and accurate intercountry estimation of cost. Of the 15 countries that participated in the clinical trial, we collected cost information in the following seven: Australia, France, Germany, the UK, Italy, Spain, and Sweden. The collection of cost data in these countries was structured through the use of worksheets to provide accurate and efficient cost reporting. We converted total average costs to average variable costs and then aggregated the data to develop study unit costs. When unit costs were unavailable, we developed an index table, based on a market-basket approach, to estimate unit costs. To estimate the cost of a given procedure, the market-basket estimation process required that cost information be available for at least one country. When cost information was unavailable in all countries for a given procedure, we estimated costs using a method based on physician-work and practice-expense resource-based relative value units. Finally, we converted study unit costs to a common currency using purchasing power parity measures. Through this costing exercise we developed a set of unit costs for patient services and per diem hospital services. We conclude by discussing the implications of our costing exercise and suggest guidelines to facilitate more effective multinational costing exercises.

Australia↗
PubMed1998

Methodological and statistical issues of quality of life (QoL) and economic evaluation in cancer clinical trials: report of a workshop.

In recent years, quality of life (QoL) and economic evaluations have become increasingly important as additional outcome measures in cancer clinical trials. However, both fields of research are relatively new and in need of finding solutions to a substantial number of specific methodological problems. This paper reports on the proceedings of a symposium aimed at summarising and discussing some of the most contentious methodological and statistical issues in QoL and economic evaluations. In addition, possible solutions are indicated and the most pertinent areas of research are identified. Issues specific to QoL evaluations that are addressed include clinically meaningful changes in QoL scores; how to analyse QoL data and to handle missing and censored data and integration of length of life and QoL outcomes. Issues specific to economic evaluations are the advantages and disadvantages of various outcome measures; statistical methods to analyse economic data and choice of decision criteria and analytical perspective. How to perform QoL and economic evaluations in large and simple trials and whether the gap between QoL and utility measures can be bridged are also discussed.

Clinical Trials as Topic↗
PubMed1998

Economic analysis of tirilazad mesylate for aneurysmal subarachnoid hemorrhage. Economic evaluation of a phase III clinical trial in Europe and Australia.

This study used data from a multinational phase III randomized, double-blind, vehicle-controlled trial to evaluate the cost-effectiveness of tirilazad mesylate (Freedox) in the treatment of aneurysmal subarachnoid hemorrhage. In men, therapy with 6 mg/kg per day of tirilazad mesylate was associated with significantly increased survival, increased cost of care, and ratios of cost per death averted that compare favorably with the ratios of other life and death interventions. In women, it appeared to have no effects on costs or survival. Further clinical studies may provide additional information about the cost-effectiveness of this intervention.

Australia↗
PubMed1998

Comparison of the use of medical resources and outcomes in the treatment of aneurysmal subarachnoid hemorrhage between Canada and the United States.

OBJECTIVE: Using data from a randomized trial of tirilazad mesylate, we assessed the differences between Canada and the United States in the use of medical resources and outcomes in the treatment of aneurysmal subarachnoid hemorrhage during the first 90 days after admission to the hospital. METHODS: Of the 877 patients for whom economic data were available, 194 were enrolled in Canada and 683 were enrolled in the United States. The differences between the countries in patient characteristics, use of medical resources, and outcomes were analyzed by comparing means and the 95% confidence intervals (CIs) around the differences in means. These differences also were predicted with use of multivariable regression analysis. RESULTS: The average hospital stay was 4.2 days longer (95% CI, 1.3 to 7.1 days) in Canada, but most of the extra stay was among patients admitted to the study in poor neurological condition. In general, however, hospital stays in Canada were substantially less intensive. Patients treated in Canada spent 3.7 fewer days (95% CI, 1.2 to 6.1 days) in nursing homes and rehabilitation centers than did patients in the United States. No statistically significant differences were seen for Glasgow Outcome Scale score, death, and occurrence of vasospasm. CONCLUSIONS: For patients admitted to the study in good neurological condition, the apparent difference in length of stay between Canada and the United States was caused by a shift in the sites of formal care rather than to the length of this care. For those admitted in poor neurological condition, both the length and sites of care differed between the two countries. No significant difference in outcomes appeared to justify these differences in the use of medical resources.

Canada↗
PubMed1997

A randomized controlled trial of epoprostenol therapy for severe congestive heart failure: The Flolan International Randomized Survival Trial (FIRST).

This trial evaluated the effects of epoprostenol on patients with severe left ventricular failure. Patients with class IIIB/IV congestive heart failure and decreased left ventricular ejection fraction were eligible for enrollment if angiography documented severely compromised hemodynamics while the patient was receiving a regimen of digoxin, diuretics, and an angiotensin-converting enzyme inhibitor. We randomly assigned 471 patients to epoprostenol infusion or standard care. The primary end point was survival; secondary end points were clinical events, congestive heart failure symptoms, distance walked in 6 minutes, and quality-of-life measures. The median dose of epoprostenol was 4.0 ng/kg/min, resulting in a significant increase in cardiac index (1.81 to 2.61 L/min/m2), a decrease in pulmonary capillary wedge pressure (24.5 to 20.0 mm Hg), and a decrease in systemic vascular resistance (20.76 to 12.33 units). The trial was terminated early because of a strong trend toward decreased survival in the patients treated with epoprostenol. Chronic intravenous epoprostenol therapy is not associated with improvement in distance walked, quality of life, or morbid events and is associated with an increased risk of death.

Aged↗
PubMed1996

BRCA1 testing in families with hereditary breast-ovarian cancer. A prospective study of patient decision making and outcomes.

OBJECTIVES: To identify predictors of utilization of breast-ovarian cancer susceptibility (BRCA1 gene) testing and to evaluate outcomes of participation in a testing program. DESIGN: Prospective cohort study with baseline interview assessment of predictor variables (eg, sociodemographic factors, knowledge about hereditary cancer and genetic testing, perceptions of testing benefits, limitations, and risks). BRCA1 test results were offered after an education and counseling session in a research setting. Outcome variables (including depression, functional health status, and prophylactic surgery plans [follow-up only]) were assessed at baseline and 1-month follow-up interviews. PARTICIPANTS: Adult male and female members (n=279) of families with BRCA1-linked hereditary breast-ovarian cancer (HBOC). RESULTS: Of subjects who completed a baseline interview (n=192), 60% requested BRCA1 test results (43% of all study subjects requested results). Requests for results were more frequent for persons with health insurance (odds ration [OR], 3.74; 95% confidence interval [CI], 2.06-6.80); more first-degree relatives affected with breast cancer (OR, 1.59; 95% CI, 1.16-2.16); more knowledge about BRCA1 testing (OR, 1.85; 95% CI, 1.36-2.50); and indicating that test benefits are important (OR, 1.45; 95% CI, 1.13-1.86). At follow-up, noncarriers of BRCA1 mutations showed statistically significant reductions in depressive symptoms and functional impairment compared with carriers and nontested individuals. Individuals identified as mutation carriers did not exhibit increases in depression and functional impairment. Among unaffected women with no prior prophylactic surgery, 17% of carriers (2/12) intended to have mastectomies and 33% (4/12) to have oophorectomies. CONCLUSIONS: Only a subset of HBOC family members are likely to request BRCA1 testing when available. Rates of test use may be higher in persons of a higher socioeconomic status and those with more relatives affected with breast cancer. For some high-risk individuals who receive test results in a research setting that includes counseling, there may be psychological benefits. More research is needed to assess the generalizability of these results and evaluate the long-term consequences of BRCA1 testing.

Adult↗
PubMed1996

Evaluation of quality of life for diverse patient populations.

Quality of life is used increasingly as a primary and secondary endpoint of clinical investigations of new therapies. Quality of life information may be especially useful for the assessment of cancer treatments, where increases in survival may be accompanied by detrimental side effects. The recognition of the importance of quality of life has led to the recent proliferation of cancer specific quality of life instruments. As more is understood about the heterogeneity of patient populations, however, we must assess how culturally defined factors may impact patient quality of life and its assessment. Quality of life instruments are diverse, ranging from those focusing on objective measures of functionality to those assessing subjective measures of patient preferences for their current health state. These instruments have been developed for use in the general population and for disease-specific populations. Assessment of the appropriateness of potential quality of life instruments in specific clinical settings, in addition to understanding the cultural diversity of the clinical population being studied, will guide the researcher in the choice of an appropriate quality of life instrument for cancer clinical trials.

Clinical Trials as Topic↗
PubMed1996

A strategy for collecting pharmacoeconomic data during phase II/III clinical trials.

This article presents an overview of the process and organisational aspects required to support the collection of pharmacoeconomic (PE) data during phase II and phase III clinical trials of pharmaceutical products. The process described requires early involvement of the PE study team in clinical trials design and planning, as well as continuing close collaboration between the PE study team and the clinical study team as the data collection plans are implemented. Adequate resources must be made available for staffing and funding the PE component of data collection and analysis. If the suggested procedures are adequately resourced and implemented, the result should be a comprehensive, complete and accurate database that will allow the PE study team to characterise the economic value of the new drug at the same time as the clinical study team characterise its safety and efficacy. Integrated clinical and economic evaluations are essential for the appropriate use of pharmaceutical products in rapidly changing markets.

Clinical Trials, Phase II as Topic↗
PubMed1994

Ethics, economics, and the publication policies of major medical journals.

OBJECTIVE: To evaluate aspects of the publication process that may affect the quality of the literature in clinical economics and biomedical ethics, and to learn about the policies of medical journals regarding disclosure of relationships between investigators and research sponsors. DESIGN: Mail survey. PARTICIPANTS: Editors in chief of 15 major medical journals. RESULTS: Twelve editors responded to the survey. Ten reported having statisticians among their editors, while only two had health economists and none had ethicists. Clinicians in the specialty field were almost always the primary reviewers of submissions, while methodologists (statisticians, health economists, or ethicists) were involved less frequently. Journals reported little knowledge of the training of their reviewers in these fields. While nine journals requested disclosure of the financial relationship between author and sponsor, only one inquired whether the sponsor's written approval was required prior to manuscript submission, and only one knew whether there was an independent steering committee for the study. CONCLUSIONS: These findings suggest that the peer review process can be strengthened to improve the quality of the medical literature in clinical economics and biomedical ethics. Journal editors also need to better understand the terms of research sponsorship agreements.

Biomedical Research↗
PubMedDate not supplied

Confidence intervals for cost-effectiveness ratios: a comparison of four methods.

We evaluated four methods for computing confidence intervals for cost-effectiveness ratios developed from randomized controlled trials: the box method, the Taylor series method, the nonparametric bootstrap method and the Fieller theorem method. We performed a Monte Carlo experiment to compare these methods. We investigated the relative performance of each method and assessed whether or not it was affected by differing distributions of costs (normal and log normal) and effects (10% absolute difference in mortality resulting from mortality rates of 25% versus 15% in the two groups as well as from mortality rates of 55% versus 45%) or by differing levels of correlation between the costs and effects (correlations of -0.50, -0.25, 0.0, 0.25 and 0.50). The principal criterion used to evaluate the performance of the methods was the probability of miscoverage. Symmetrical miscoverage of the intervals was used as a secondary criterion for evaluating the four methods. Overall probabilities of miscoverage for the nonparametric bootstrap method and the Fieller theorem method were more accurate than those for the other the methods. The Taylor series method had confidence intervals that asymmetrically underestimated the upper limit of the interval. Confidence intervals for cost-effectiveness ratios resulting from the nonparametric bootstrap method and the Fieller theorem method were more dependably accurate than those estimated using the Taylor series or box methods. Routine reporting of these intervals will allow individuals using cost-effectiveness ratios to make clinical and policy judgments to better identify when an intervention is a good value for its cost.

Computer Simulation↗