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Biomedical subjects

M C Weinstein

Publications and source records attributed to M C Weinstein.

At least 19 recordsLinked to original sources
PubMed2000

Cost-effectiveness of screening for anal squamous intraepithelial lesions and anal cancer in human immunodeficiency virus-negative homosexual and bisexual men.

PURPOSE: Homosexual and bisexual men are at an increased risk for human papillomavirus-induced squamous intraepithelial lesions and cancer of the anus. Our objective was to estimate the cost-effectiveness of screening for anal squamous intraepithelial lesions in these high-risk patients. SUBJECTS AND METHODS: A Markov model was developed to evaluate alternative screening strategies using anal cytology in a hypothetical cohort of homosexual and bisexual men. Data were obtained from prospective cohort studies, national databases, Medicare reimbursement rates, and the published literature. Model outcomes included life expectancy, quality-adjusted life expectancy, total lifetime costs, and incremental cost-effectiveness ratios. RESULTS: The undiscounted life expectancy gain associated with anal cytology screening every 3 years was 5.5 months. Compared with no screening, screening every 3 years increased the discounted quality-adjusted life expectancy by 1.8 months and cost $7,000 per quality-adjusted life year (QALY) gained. Screening every 2 years cost $15,100 per QALY gained compared with screening every 3 years. Annual screening provided incremental benefits of less than 0.5 quality-adjusted months and had an incremental cost of $34,800 per QALY gained. Screening every 6 months provided little additional benefit (i.e, 5 days) over that of annual screening and had an incremental cost of $143,500 per QALY gained. CONCLUSION: In homosexual and bisexual men, screening every 2 or 3 years for anal squamous intraepithelial lesions with anal cytology would provide life-expectancy benefits comparable with other accepted preventive health measures, and would be cost-effective.

Adult↗
PubMed2000

Cost-effectiveness of cholesterol-lowering therapies according to selected patient characteristics.

BACKGROUND: The National Cholesterol Education Program Expert Panel on Detection, Evaluation, and Treatment of High Blood Cholesterol in Adults (Adult Treatment Panel II) recommends treatment guidelines based on cholesterol level and number of risk factors. OBJECTIVE: To evaluate how the cost-effectiveness ratios of cholesterol-lowering therapies vary according to different risk factors. DESIGN: Cost-effectiveness analysis. DATA SOURCES: Published data. TARGET POPULATION: Women and men 35 to 84 years of age with low-density lipoprotein cholesterol levels of 4.1 mmol/L or greater (> or =160 mg/dL), divided into 240 risk subgroups according to age, sex, and the presence or absence of four coronary heart disease risk factors (smoking status, blood pressure, low-density lipoprotein cholesterol level, and high-density lipoprotein cholesterol level). TIME HORIZON: 30 years. PERSPECTIVE: Societal. INTERVENTIONS: Step I diet, statin therapy, and no preventive treatment for primary and secondary prevention. OUTCOME MEASURES: Incremental cost-effectiveness ratios. RESULTS OF BASE-CASE ANALYSIS: Incremental cost-effectiveness ratios for primary prevention with step I diet ranged from $1900 per quality-adjusted life-year (QALY) gained to $500000 per QALY depending on risk subgroup characteristics. Primary prevention with a statin compared with diet therapy was $54000 per QALY to $1400000 per QALY. Secondary prevention with a statin cost less than $50000 per QALY for all risk subgroups. RESULTS OF SENSITIVITY ANALYSIS: The inclusion of niacin as a primary prevention option resulted in much less favorable incremental cost-effectiveness ratios for primary prevention with a statin (>$500000 per QALY). CONCLUSIONS: Cost-effectiveness of treatment strategies varies significantly when adjusted for age, sex, and the presence or absence of additional risk factors. Primary prevention with a step I diet seems to be cost-effective for most risk subgroups but may not be cost-effective for otherwise healthy young women. Primary prevention with a statin may not be cost-effective for younger men and women with few risk factors, given the option of secondary prevention and of primary prevention in older age ranges. Secondary prevention with a statin seems to be cost-effective for all risk subgroups and is cost-saving in some high-risk subgroups.

Adult↗
PubMed2000

Preference-based measures in economic evaluation in health care.

Estimating preferences for states of health has been an active area of research in recent years. Unlike psychophysical approaches, which discriminate levels of health status, preference-based approaches incorporate values or utilities for health outcomes and can be used in cost-effectiveness analyses to aid resource allocation decisions. This chapter considers issues and controversies involved in using preference-based measures in economic evaluation in health care, with a particular emphasis on cost-utility analysis and the estimation of quality-adjusted life years. Topics considered include techniques for measuring preferences, the use of preference-based classification systems, the relationship between patient and community preferences, methods for obtaining utilities from clinical trials, mapping health status from health utilities, the development of "off-the-shelf" preference weights, and proposed alternatives to quality-adjusted life years. We also consider applications of cost-utility analyses to public health interventions. Although cost-utility analyses have become more popular recently, many challenges remain for the field. Widespread acceptance of the methodology likely awaits more consensus on measurement techniques, as well as educational efforts in the public health and medical communities on the usefulness of the approach.

Alzheimer Disease↗
PubMed2000

Who gets chemotherapy for metastatic lung cancer?

STUDY OBJECTIVES: To determine the prevalence and factors associated with chemotherapy use in elderly patients presenting with advanced lung cancer. DESIGN: A retrospective cohort study using administrative data. SETTING AND PATIENTS: We analyzed the medical bills for the 6,308 Medicare patients > 65 years old with diagnosed stage IV non-small cell lung cancer (NSCLC) in the 11 SEER (survival, epidemiology, and end results) regions between 1991 and 1993. The main outcome measure, chemotherapy administration, was identified by the relevant medical billing codes. Patient sociodemographic and disease characteristics were obtained from the SEER database and census data. RESULTS: Almost 22% of patients received chemotherapy at some time for their metastatic NSCLC. As expected, younger patients and those with fewer comorbid conditions were more likely to receive chemotherapy. However, several nonmedical factors, such as nonblack race, higher socioeconomic status, treatment in a teaching hospital, and living in the Seattle/Puget Sound or Los Angeles SEER regions, also significantly increased a patient's likelihood of receiving chemotherapy. CONCLUSION: Compared to previous reports, the prevalence of chemotherapy use for advanced NSCLC appears to be increasing. However, despite uniform health insurance coverage, there is wide variation in the utilization of palliative chemotherapy among Medicare patients, and nonmedical factors are strong predictors of whether a patient receives chemotherapy. While it is impossible to know the appropriate rate of usage, nonmedical factors should only influence a patient's likelihood of receiving treatment if they reflect patient treatment preference. Research to further clarify the costs, benefits, and patient preferences for chemotherapy in this patient population is warranted in order to minimize the effect of nonmedical biases on management decisions.

Aged↗
PubMed2000

Barriers to using cost-effectiveness analysis in managed care decision making.

Managed care organizations would appear to be natural advocates for, and users of, cost-effectiveness analysis (CEA) as a tool for maximizing health outcomes for their covered populations within fixed budgets. There is, however, little evidence that CEA plays a major role in managed care decision making. The purpose of this paper is to identify barriers to both conducting and using CEA in managed care decision making. Lack of understanding about the value and applicability of CEA, and incentives that do not align with a lifetime perspective on either health outcomes or costs may be at least as important as perceived or real methodological limitations of the methodology. Research focused on ways to overcome these barriers, and thereby improve resource allocations, is recommended.

Cost-Benefit Analysis↗
PubMed1999

Expert panel vs decision-analysis recommendations for postdischarge coronary angiography after myocardial infarction.

CONTEXT: Expert panels and decision-analytic techniques are increasingly used to determine the appropriateness of medical interventions, but these 2 approaches use different methods to process evidence. OBJECTIVE: To compare expert panel appropriateness ratings of coronary angiography after myocardial infarction (from the time of hospital discharge to 12 weeks after infarction) with the health gains and cost-effectiveness predicted by a decision-analytic model. DESIGN: Comparison of the degree of importance of the clinical variables considered in expert panel appropriateness ratings vs a previously published decision-analytic model. Identification of 36 clinical scenarios from the expert panel that could be simulated by the decision-analytic model. MAIN OUTCOME MEASURES: Appropriateness score and appropriateness classification (expert panel) vs gain in quality-adjusted life-years (QALYs) and incremental cost-effectiveness ratio (decision-analytic model). RESULTS: The most important clinical variables were similar in the 2 approaches, with the exercise tolerance test result exerting the greatest leverage on strength of recommendation for angiography. Among the expert panel clinical scenarios considered to be appropriate for coronary angiography that could be simulated in the decision-analysis model, the median (interquartile range) health gain and incremental cost-effectiveness ratio were 0.59 (0.41-0.76) QALYs and $27000 ($23000-$35000) per QALY gained, respectively. Among the clinical scenarios that expert panels considered inappropriate, the corresponding medians (interquartile ranges) were 0.24 (0.19-0.34) QALYs and $54000 ($36000-$58000) per QALY gained. The Spearman rank correlation between appropriateness score and QALY gain was 0.58 (P<.001) and between appropriateness score and estimated incremental cost-effectiveness ratios was -0.66 (P<.001). CONCLUSIONS: For the 36 expert panel scenarios that could be simulated by the decision-analytic model, there was moderate to good agreement between the appropriateness score and both the health gain and the incremental cost-effectiveness ratio of coronary angiography compared with no angiography in the convalescent phase of acute myocardial infarction, but several scenarios judged as inappropriate by the expert panel approach had cost-effectiveness ratios comparable with many generally recommended medical interventions. Formal synthesis of expert judgment and decision modeling is warranted in future efforts at guideline development.

Adult↗
PubMed1999

The clinical effectiveness and cost-effectiveness of screening for anal squamous intraepithelial lesions in homosexual and bisexual HIV-positive men.

CONTEXT: Homosexual and bisexual men infected with human immunodeficiency virus (HIV) are at increased risk for human papillomavirus-related anal neoplasia and anal squamous cell carcinoma (SCC). OBJECTIVE: To estimate the clinical benefits and cost-effectiveness of screening HIV-positive homosexual and bisexual men foranal squamous intraepithelial lesions (ASIL) and anal SCC. DESIGN: Cost-effectiveness analysis performed from a societal perspective that used reference case recommendations from the Panel on Cost-Effectiveness in Health and Medicine. A state-transition Markov model was developed to calculate lifetime costs, life expectancy, and quality-adjusted life expectancy for no screening vs several screening strategies for ASIL and anal SCC using anal Papanicolaou (Pap) testing at different intervals. Values for incidence, progression, and regression of anal neoplasia; efficacy of screening and treatment; natural history of HIV; health-related quality of life; and costs were obtained from the literature. SETTING AND PARTICIPANTS: Hypothetical cohort of homosexual and bisexual HIV-positive men living in the United States. MAIN OUTCOME MEASURES: Life expectancy, quality-adjusted life expectancy, quality-adjusted years of life saved, lifetime costs, and incremental cost-effectiveness ratio. RESULTS: Screening for ASIL increased quality-adjusted life expectancy at all stages of HIV disease. Screening with anal Pap tests every 2 years, beginning in early HIV disease (CD4 cell count >0.50 x 10(9)/L), resulted in a 2.7-month gain in quality-adjusted life expectancy for an incremental cost-effectiveness ratio of $13,000 per quality-adjusted life year saved. Screening with anal Pap tests yearly provided additional benefit at an incremental cost of $16,600 per quality-adjusted life year saved. If screening was not initiated until later in the course of HIV disease (CD4 cell count <0.50 x 10(9)/L), then yearly Pap test screening was preferred due to the greater amount of prevalent anal disease (cost-effectiveness ratio of less than $25,000 per quality-adjusted life year saved compared with no screening). Screening every 6 months provided little additional benefit over that of yearly screening. Results were most sensitive to the rate of progression of ASIL to anal SCC and the effectiveness of treatment of precancerous lesions. CONCLUSIONS: Screening HIV-positive homosexual and bisexual men for ASIL and anal SCC with anal Pap tests offers quality-adjusted life expectancy benefits at a cost comparable with other accepted clinical preventive interventions.

Adult↗
PubMed1999

Cost-effectiveness of donepezil in the treatment of mild or moderate Alzheimer's disease.

OBJECTIVE: To demonstrate the use of cost-effectiveness analysis to assess the economic impact of donepezil in the treatment of mild or moderate AD. BACKGROUND: Cost-effectiveness analyses show the relationship between resources used (costs) and health benefits achieved (effects) for an intervention compared with an alternative strategy. METHODS: We developed a model to estimate the incremental cost-effectiveness of donepezil compared with no treatment. We determined costs per quality-adjusted life-years gained, a measurement that enhances the comparability of diverse studies. The model projects the progression of AD patients into more severe disease stages and into nursing homes. Data from a randomized clinical trial of donepezil were used to assess the drug's impact on the 6-week probabilities of progression. Data on the costs and health-related quality of life associated with different disease stages and settings were taken from published estimates and our companion cross-sectional study, respectively. RESULTS: Donepezil costs are partially offset by a reduction in the costs of care due to enhancement in cognitive functioning and the delay to more costly disease stages and settings. The magnitude of this cost offset and of the effect of donepezil on health-related quality of life depends on the model's assumptions about the duration of the drug effect, where controlled data are lacking. If the drug effect exceeds 2 years, the model predicts that for mild AD the drug would pay for itself in terms of cost offsets. CONCLUSIONS: The results of the cost-effectiveness model presented here suggest that donepezil may be cost-effective but additional controlled data on long-term drug efficacy are needed.

Alzheimer Disease↗
PubMed1999

The costs, clinical benefits, and cost-effectiveness of screening for cervical cancer in HIV-infected women.

BACKGROUND: Women with HIV infection have a higher risk for cervical squamous intraepithelial lesions than do women without HIV infection, and the optimal regimen for cervical cancer screening in these women is uncertain. OBJECTIVE: To assess the net health consequences, costs, and cost-effectiveness of various screening strategies for cervical neoplasia and cancer in HIV-infected women. DESIGN: A cost-effectiveness analysis from a societal perspective done by using a state-transition Markov model. Values for incidence, progression, and regression of cervical neoplasia; efficacy of screening and treatment; progression of HIV disease; mortality from HIV infection and cancer; quality of life; and costs were obtained from the literature. SETTING: Simulated clinical practice in the United States. PATIENTS: HIV-infected women representative of the U.S. population. INTERVENTION: Six main screening strategies--no screening, annual Papanicolaou smears, annual Papanicolaou smears after two negative smears obtained 6 months apart (recommended by the Centers for Disease Control and Prevention), semiannual Papanicolaou smears, annual colposcopy, and semiannual colposcopy--were considered. MEASUREMENTS: Quality-adjusted life-years (QALYs), lifetime costs, and incremental cost-effectiveness. RESULTS: Annual Papanicolaou smear screening resulted in a 2.1-month gain in quality-adjusted life expectancy for an incremental cost of $12,800 per QALY saved. Annual Papanicolaou smear screening after two negative smears obtained 6 months apart provided an additional 0.04 QALYs at a cost of $14,800 per QALY saved. Semiannual Papanicolaou smear screening provided a further 0.17 QALYs at a cost of $27,600 per QALY saved. Annual colposcopy cost more but provided no additional benefit compared with that given by semiannual Papanicolaou smear screening, and semiannual colposcopy exceeded $375,000 per QALY saved. Results were most sensitive to the rate of progression of neoplasia to invasive cancer. CONCLUSIONS: In HIV-infected women, cervical cancer screening with annual Papanicolaou smears after two negative smears obtained 6 months apart offers quality-adjusted life expectancy benefits at a cost comparable to that of other clinical preventive interventions.

Algorithms↗
PubMed1999

The relative influence of secondary versus primary prevention using the National Cholesterol Education Program Adult Treatment Panel II guidelines.

OBJECTIVES: This study was undertaken to project the population-wide effect of full implementation of the Adult Treatment Panel (ATP) II guidelines of the National Cholesterol Education Program (NCEP). BACKGROUND: The ATP II has proposed guidelines for cholesterol reduction, but the long-term epidemiologic influence of its components has not been fully examined. METHODS: We used a calibrated, validated simulation of the U.S. population, aged 35 to 84 years to estimate the potential for the NCEP guidelines, under varying assumptions, to reduce coronary heart disease morbidity and mortality and overall mortality from the years 2000 to 2020. RESULTS: Primary prevention would yield only about half of the benefits of secondary prevention despite requiring nearly twice as many person-years of treatment. The projected increase in quality-adjusted years of life per year of treatment for secondary prevention was 3- to 12-fold higher than for primary prevention. To yield population-wide epidemiologic benefits equivalent to NCEP recommendations for secondary prevention, primary prevention would require a nearly sixfold increase in the number of persons treated compared with NCEP recommendations. All benefits of universal success of the NCEP primary prevention "screen and treat" guidelines could be achieved by a 11 mg/dl (8%) population-wide reduction in low-density lipoprotein cholesterol levels among persons without preexisting coronary heart disease. CONCLUSIONS: The NCEP guidelines for targeted primary prevention can be a useful component of a rational public health strategy, but only as a complement to the more appealing strategies of secondary prevention and "across-the-board" programs to lower all cholesterol levels.

Adult↗
PubMed1999

Health utilities in Alzheimer's disease: a cross-sectional study of patients and caregivers.

OBJECTIVES: Although the broad impacts of Alzheimer's disease (AD) are increasingly recognized, little work has focused on the overall health-related quality of life experienced by Alzheimer's disease patients and their caregivers. The study had two main objectives: (1) to test the feasibility of measuring health utilities in Alzheimer's disease with a generic preference-weighted instrument using proxy respondents and (2) to assess the utility scores of Alzheimer's disease patients (and their caregivers) in different disease stages and care setting. METHODS: A cross-sectional study of 679 Alzheimer's disease patient/caregiver pairs was conducted at 13 sites in the United States: four academic medical centers, four managed care plans, two assisted living facilities, and three nursing homes. The Health Utilities Index Mark II (HUI:2) questionnaire was administered to caregivers of patients who responded both as proxies for patients and for themselves. Responses to the questionnaire were converted into a global utility score, between 0 and 1, using the HUI:2 multi-attribute utility function. RESULTS: Global utility scores varied considerably across patients' Alzheimer's disease stage: for the six stages assessed (questionable, mild, moderate, severe, profound, and terminal), mean utility scores were 0.73, 0.69, 0.53, 0.38, 0.27, and 0.14, respectively. In multiple regression analyses, Alzheimer's disease stage was a negative and significant predictor of utility scores for patients; setting did not exert an independent effect. Utility scores for the caregivers were insensitive to patients' Alzheimer's disease stage and setting. CONCLUSIONS: Patients' Alzheimer's disease stage had a substantial influence on health utilities, as measured by the HUI:2. More research is needed to assess the validity of using proxy respondents.

Activities of Daily Living↗
PubMed1999

The cost-effectiveness of prophylaxis for Mycobacterium avium complex in AIDS.

OBJECTIVE: To develop a simulation model to project costs, life expectancy, and cost-effectiveness in discounted dollars per quality-adjusted life-year (QALY) saved for clinical strategies to prevent Mycobacterium avium complex (MAC) in patients with AIDS. METHODS: We used natural history data from the Multicenter AIDS Cohort Study, efficacy and toxicity data from randomized clinical trials, and cost data from the AIDS Cost and Services Utilization Survey. The model permits timing of prophylaxis to be stratified by CD4 count (201-300, 101-200, 51-100, and < or = 50/mm3), and allows combinations of prophylaxis, crossover to second- and third-line agents for toxicity, and consideration of adherence, resistance, and quality of life. RESULTS: The model projects that the average HIV-infected patient with a beginning CD4 count between 201 and 300/mm3 has total lifetime costs of approximately $43,150 and a quality-adjusted life expectancy of 42.35 months. If azithromycin prophylaxis for M. avium complex is begun after the CD4 declines to 50/mm3, costs and quality-adjusted survival increase to approximately $44,040 and 42.78 months, respectively, for an incremental cost-effectiveness ratio of $25,000/QALY compared with no M. avium complex prophylaxis. Other prophylaxis options (i.e., rifabutin, clarithromycin, and combination therapies) either cost more but offer shorter survival, or have cost-effectiveness ratios above $260,000/QALY. Sensitivity analysis reveals that, for reasonable assumptions about quality of life, risk of infection, prophylaxis cost, adherence, and resistance, azithromycin remains the most cost-effective prophylaxis option. CONCLUSIONS: Azithromycin prophylaxis, begun after the CD4 count has declined to 50/mm3, is the most cost-effective M. avium complex prophylaxis strategy. Consistent with new United States Public Health Service guidelines, it should be the first-line prophylaxis option.

AIDS-Related Opportunistic Infections↗
PubMed1998

Gains in life expectancy from medical interventions--standardizing data on outcomes.

BACKGROUND: The gain in life expectancy is an important measure of the effectiveness of medical interventions, but its interpretation requires that it be placed in context. The interpretation of gains in life expectancy is particularly problematic for preventive interventions, for which the gains are often just weeks or even days when averaged across the entire target population. METHODS: We tabulated the gains in life expectancy from a variety of medical interventions as reported in 83 published sources and categorized them according to target population and disease. We considered prevention in populations at average risk for particular diseases, prevention in populations at elevated risk, and treatments in populations with established disease. RESULTS: The gains in life expectancy from preventive interventions in populations at average risk ranged from less than one month to slightly more than one year per person receiving the intervention, but the gains were as high as five years or more if the prevention was targeted at persons at especially high risk. The gains in life expectancy from treatments of established disease ranged from several months (for coronary thrombolysis and revascularization to treat heart disease) to as long as nine years (for chemotherapy to treat advanced testicular cancer). CONCLUSIONS: A gain in life expectancy from a medical intervention can be categorized as large or small by comparing it with gains from other interventions aimed at the same target population. A gain in life expectancy of a month from a preventive intervention targeted at populations at average risk and a gain of a year from a preventive intervention targeted at populations at elevated risk can both be considered large. The framework we developed for standardizing gains in life expectancy can be used in the interpretation of data on the outcomes of interventions.

Adolescent↗
PubMed1998

The cost-effectiveness of preventing AIDS-related opportunistic infections.

CONTEXT: Multiple options are now available for prophylaxis of opportunistic infections related to the acquired immunodeficiency syndrome (AIDS). However, because of differences in incidence rates as well as drug efficacy, toxicity, and costs, the role of different types of prophylaxis remains uncertain. OBJECTIVE: To determine the clinical impact, cost, and cost-effectiveness of strategies for preventing opportunistic infections in patients with advanced human immunodeficiency virus (HIV) disease. DESIGN: We developed a Markov simulation model to compare different strategies for prophylaxis of Pneumocystis carinii pneumonia (PCP), toxoplasmosis, Mycobacterium avium complex (MAC) infection, fungal infections, and cytomegalovirus (CMV) disease in HIV-infected patients. Data for the model were derived from the Multicenter AIDS Cohort Study, randomized controlled trials, and the national AIDS Cost and Services Utilization Survey. MAIN OUTCOME MEASURES: Projected life expectancy, quality-adjusted life expectancy, total lifetime direct medical costs, and cost-effectiveness in dollars per quality-adjusted life-year (QALY) saved. RESULTS: For patients with CD4 cell counts of 0.200 to 0.300 x 10(9)/L (200-300/microL) who receive no prophylaxis, we projected a quality-adjusted life expectancy of 39.08 months and average total lifetime costs of $40288. Prophylaxis for PCP and toxoplasmosis with trimethoprim-sulfamethoxazole for patients with CD4 cell counts of 0.200 x 10(9)/L (200/microL) or less increased quality-adjusted life expectancy to 42.56 months, implying an incremental cost of $16000 per QALY saved. Prophylaxis for MAC for patients with CD4 cell counts of 0.050 x 10(9)/L (50/microL) or less produced smaller gains in quality-adjusted life expectancy; incremental cost-effectiveness ratios were $35000 per QALY saved for azithromycin and $74000 per QALY saved for rifabutin. Oral ganciclovir for the prevention of CMV infection was the least cost-effective prophylaxis ($314000 per QALY saved). Results were most sensitive to the risk of developing an opportunistic infection, the impact of opportunistic infection history on long-term survival, and the cost of prophylaxis. CONCLUSIONS: The cost-effectiveness of prophylaxis against HIV-related opportunistic infections varies widely, but prophylaxis against PCP or toxoplasmosis and against MAC delivers the greatest comparative value. In an era of limited resources, these results can be used to set priorities and explore new alternatives for improving HIV patient care.

AIDS-Related Opportunistic Infections↗
PubMed1998

Heterogeneity in the relationship between the time tradeoff and Short Form-36 for HIV-infected and primary care patients.

OBJECTIVES: Evidence in the literature suggests that the overall correlation between descriptive and valuational measures of health are weak to moderate. In this study, the relationship between descriptive health status measures, obtained using the Short-Form 36, and health values, measured with the time tradeoff, was explored. METHODS: Two groups of patients matched for age and gender were interviewed. One group comprised 139 human immunodeficiency virus (HIV)-infected patients; the other group comprised 124 primary care patients. The relationship between the SF-36 and the time tradeoff was estimated, assuming homogeneity across patients, using multiple regression analysis. Subsequently, the relationship was examined assuming heterogeneity across patients and using the expectation maximization algorithm in a maximum likelihood context (latent class analysis). RESULTS: Four classes, representing 47%, 13%, 8%, and 32% of the population, respectively, were found. The overall percentage of variation explained under the assumption of a homogeneous relationship was only 33% as compared with 85% when heterogeneity was accounted for. Only three characteristics (educational level, employment status, and the SF-36 social functioning score) sufficed to generate a nearly perfect classification of the patients. CONCLUSIONS: Heterogeneity across subjects should be taken into account in describing the relationship between health values and health status dimensions.

Attitude to Health↗
PubMed1998

The impact of risk information on patients' willingness to pay for autologous blood donation.

OBJECTIVES: For contingent valuation to provide valid values for policy making, it is important that respondents be well informed about the goods they are asked to value. Few studies, however, have tested the impact of providing this information This study assessed the impact of risk information on patients' willingness to pay for autologous blood donation and derived the willingness to pay in a sample of informed patients. METHODS: Patients were randomized either to receive information about the risks of complications from allogeneic (volunteer) blood transfusions or to base their willingness to pay responses on their own prior knowledge. Four hundred twelve autologous blood donors were recruited from three study sites. Self-administered questionnaires collected information on willingness to pay, risk perceptions, and socioeconomic information. RESULTS: As predicted by our theoretical model, providing risk information reduced the variance in the willingness to pay for autologous blood donation. A tendency for information to reduce the willingness to pay was also found, suggesting that uninformed patients, on average, overestimate the risks of allogeneic blood transfusions. The median willingness to pay in the informed sample was approximately $750 to $1,100, depending on the estimation method, compared with $800 to $1,900 in the uninformed group. Willingness to pay was significantly related to perceived transfusion risk, personal income, and dread of transfusions. CONCLUSIONS: Our results are consistent with an economic model where individuals update their prior risk perceptions with new information. The willingness to pay in the informed sample was far higher than the costs of autologous blood donation, suggesting that total benefits outweigh the costs of the procedure.

Adult↗
PubMed1998

Evaluating the cost-effectiveness of clinical and public health measures.

Cost-effectiveness analysis, an analytic tool that expresses as a ratio the cost of obtaining an additional unit of health outcome, can help decision makers achieve more health protection for the same or less cost. We characterize the state of the cost-effectiveness analysis literature by reviewing how this technique is applied to various clinical and public health interventions. We describe the results of cost-effectiveness analyses for over 40 interventions to reduce cancer, heart disease, trauma, and infectious disease. The cost-effectiveness ratios for these interventions vary enormously, from interventions that save money to those that cost more than $1 million per year of life gained. The methods used to derive the cost-effectiveness ratios also vary considerably, and we summarize this variation within each health area. Greater uniformity of analytical practice will be necessary if cost-effectiveness analysis is to become a more influential tool in debates about resource allocation.

Communicable Disease Control↗