Abdominal aortic aneurysm screening: how many life years lost from underuse of the medicare screening benefit?

BACKGROUND: Since 2007, Medicare has provided one-time abdominal aortic aneurysm (AAA) screening for men with smoking history, and men and women with a family history of AAA as part of its Welcome to Medicare visit. OBJECTIVE: We examined utilization of the new AAA screening benefit and estimated how increased utilization could influence population health as measured by life years gained. Additionally, we explored the impact of expanding screening to women with smoking history. DESIGN: Analysis of Medicare claims and a simulation model to estimate the effects of screening, using published data for parameter estimates. SETTING: AAA screening in the primary care setting. PATIENTS: Newly-enrolled Medicare beneficiaries aged 65 years, with smoking history or family history of AAA. MAIN MEASURES: Life expectancy, 10-year survival rates. KEY RESULTS: Medicare data revealed low utilization of AAA screening, under 1% among those eligible. We estimate that screening could increase life expectancy per individual invited to screening for men with smoking history (0.11 years), with family history of AAA (0.17 years), and women with family history (0.08 years), and smoking history (0.09 years). Average gains of 131 life years per 1,000 persons screened for AAA compare favorably with the grade B United States Preventive Services Task Force (USPSTF) recommendation for breast cancer screening, which yields 95-128 life years per 1,000 women screened. These findings were robust over a range of scenarios. LIMITATIONS: The simulation results reflect assumptions regarding AAA prevalence, treatment, and outcomes in specific populations based on published research and US survey data. Published data on women were limited. CONCLUSIONS: The Welcome to Medicare and AAA screening benefits have been underutilized. Increasing utilization of AAA screening would yield substantial gains in life expectancy. Expanding screening to women with smoking history also has the potential for substantial health benefits.

Quality-adjusted life years in cancer: pros, cons, and alternatives.

High and rising cancer treatment costs have forced a discussion about the use of cost-effectiveness analyses and other approaches to assess the value of cancer care. Oncologists have traditionally resisted using economic considerations in day-to-day medical considerations, though unavoidably their decisions have important resource implications, and increasingly economic realities are impacting their actions. In this paper, we summarise the use of the quality-adjusted life years to assess the value of cancer care and suggest potential ways to improve upon value measurement in cancer coverage and reimbursement decisions.

Cost-effectiveness of migraine prevention: the case of topiramate in the UK.

The aim of this study was to assess the cost-effectiveness of topiramate vs. no preventive treatment in the UK. Model inputs included baseline migraine frequency, treatment discontinuation and response, preventive and acute medical cost per attack [2005 GBP ( pound)] and gain in health utility. Outcomes included monthly migraines averted, acute and preventive treatment costs and cost per quality-adjusted life year (QALY). Topiramate was associated with 1.8 fewer monthly migraines and a QALY gain of 0.0384. The incremental cost of topiramate vs. no preventive treatment was about 10 UK pounds per migraine averted and 5700 UK pounds per QALY. Results are sensitive to baseline monthly migraine frequency, triptan use rate and the gain in utility. Incorporating savings from reduced work loss (about 36 UK pounds per month) suggests that topiramate would be cost saving compared with no preventive treatment. This analysis suggests that topiramate is a cost-effective treatment for migraine prevention compared with no preventive treatment.

Predictors of hospital length of stay and cost in patients with intracerebral hemorrhage.

We used the 2002 Healthcare Cost and Utilization Project Nationwide Inpatient Sample to assess hospital length of stay (LOS) and cost among adults with a principal diagnosis of intracerebral hemorrhage (n = 13,239). Sixty-nine percent of patients were aged > or =65 years, and 31% died during hospitalization. Mean LOS (cost) was 7.7 days (15,256 dollars) (survivors: 9.6 days, 17,442 dollars). Patient, hospital, and payer characteristics accounted for 69.1% of variation in cost per discharge.

Modeling for health care and other policy decisions: uses, roles, and validity.

The role of models to support recommendations on the cost-effective use of medical technologies and pharmaceuticals is controversial. At the heart of the controversy is the degree to which experimental or other empirical evidence should be required prior to model use. The controversy stems in part from a misconception that the role of models is to establish truth rather than to guide clinical and policy decisions. In other domains of public policy that involve human life and health, such as environmental protection and defense strategy, models are generally accepted as decision aids, and many models have been formally incorporated into regulatory processes and governmental decision making. We formulate an analytical framework for evaluating the role of models as aids to decision making. Implications for the implementation of Section 114 of the Food and Drug Administration Modernization Act (FDAMA) are derived from this framework.

Public attitudes about genetic testing for Alzheimer's disease.

In a general population survey (N = 314), 79 percent of respondents stated that they would take a hypothetical genetic test to predict whether they will eventually develop Alzheimer's disease. The proportion fell to 45 percent for a "partially predictive" test (which had a one in ten chance of being incorrect). Inclination to obtain testing was similar across age groups. Respondents were willing to pay $324 for the completely predictive test. Respondents stated that if they tested positive, they would sign advance directives (84 percent), get their finances in order (74 percent), and purchase long-term care insurance (69 percent). Only a third of respondents expressed concern about confidentiality. The results suggest that people value genetic testingfor personal and financial reasons, but they also underscore the need to counsel potential recipients carefully about the accuracy and implications of test information.

Measuring Alzheimer's disease progression with transition probabilities: estimates from CERAD.

OBJECTIVES: To estimate annual transition probabilities (i.e., the likelihood that a patient will move from one disease stage to another in a given time period) for AD progression. Transition probabilities are estimated by disease stages (mild, moderate, severe) and settings of care (community, nursing home), accounting for differences in age, gender, and behavioral symptoms as well as the length of time a patient has been in a disease stage. METHODS: Using data from the Consortium to Establish a Registry for Alzheimer's Disease (CERAD), the authors employed a modified survival analysis to estimate stage-to-stage and stage-to-nursing home transition probabilities. To account for individual variability, a Cox proportional hazards model was fit to the CERAD data to estimate hazard ratios for gender, age (50 to 64, 65 to 74, and more than 75 years), and level of behavioral symptoms (low/high, according to responses to the Behavioral Rating Scale for Dementia) for each of the key stage-to-stage and stage-to-nursing home transitions. RESULTS: The transition probabilities underscore the rapid progression of patients into more severe disease stages and into nursing homes and the differences among population subgroups. In general, male gender, age under 65, and high level of behavioral symptoms were associated with higher transition probabilities to more severe disease stages. Disease progression is roughly constant as a function of the time a patient has spent in a particular stage. CONCLUSIONS: Transition probabilities provide a useful means of characterizing AD progression. Economic models of interventions for AD should consider the varied course of progression for different population subgroups, particularly those defined by high levels of behavioral symptoms.

The association between caregiver burden and caregiver health-related quality of life in Alzheimer disease.

The burden experienced by family caregivers of individuals with Alzheimer disease (AD) affects the caregivers' overall health-related quality of life (HRQOL). Assessing the influence on HRQOL is an integral part of determining the efficacy and economic attractiveness of interventions for AD. Generic preference-weighted instruments such as the Health Utilities Index Mark 2 (HUI2) are recommended for measuring HRQOL for cost-effectiveness studies. However, these instruments focus on physical attributes and have not been tested in an AD caregiver population. We administered the HUI2 to a population of 679 caregivers to people with AD at 13 community and institutional sites in the United States. We also administered the Medical Outcomes Study 36-Item Short-Form Health Survey (SF-36), a caregiver time questionnaire, and a caregiver burden instrument. The mean global HUI2 utility score for caregivers was 0.87 and varied little by the affected person's setting of care and AD stage (range, 0.86-0.89; p > 0.2). The caregiver burden scales all varied by the affected person's setting of care, and some also varied by disease severity. The mental health component summary score of the SF-36 for caregivers varied across both disease stage and setting. Caregiver time increased for caregivers of AD-affected persons with more severe cognitive impairment. Generic preference-weighted instruments may not adequately capture differences in the burden of caregivers of those with AD. The development of condition-specific preference-weighted instruments may provide the means to better estimate HRQOL in AD caregivers.

An off-the-shelf help list: a comprehensive catalog of preference scores from published cost-utility analyses.

PURPOSE: The Panel on Cost-Effectiveness in Health and Medicine recommends an organized collection of preference measure values for health states that can be used in costutility analyses (CUAs). The authors sought to construct a catalog of preference scores from published CUAs, organize the catalog by clinical categories, and identify methods of preference score assessment. METHOD: The authors systematically searched Medline and other databases to identify original CUAs published through 1997. Information was abstracted on the health state descriptions, corresponding preference scores, method of preference score elicitation, and the source of the estimate. RESULTS: Two hundred twenty-eight CUAs were appraised. The authors found 949 health states and corresponding preference scores. Most frequently, health states pertained to the circulatory system (21.7%), health states were valued by experts (35.8%), and values were derived through community-based preference scores (23.5%). CONCLUSION: A catalog of preference scores for health states can be constructed. The catalog (http://www.hsph.harvard.edu/organizations/hcra/cuadatabase/ intro.html) may provide a useful reference tool for producers and consumers of CUAs but also underscores the methodologic variation and inconsistencies present in the field.

Cost-effectiveness of inhaled corticosteroids in adults with mild-to-moderate asthma: results from the asthma policy model.

BACKGROUND: Inhaled corticosteroids remain underused among United States-based clinicians in treating mild-to-moderate adult asthma. OBJECTIVE: The purpose of this investigation was to estimate the clinical impact, health-related quality of life, cost, and cost-effectiveness of inhaled corticosteroid therapy in a population of patients aged 18 years and over with FEV(1) = 60% to 100% of predicted normal. METHODS: We performed a cost-effectiveness analysis of quick relievers (eg, short-acting beta-agonists) on an as-needed basis plus inhaled corticosteroid therapy versus quick relievers alone. A mathematical simulation model was developed to forecast symptoms, acute exacerbations, quality-adjusted life-years (QALYs), health care costs, and cost-effectiveness, measured in both dollars per QALY gained and dollars per symptom-free day gained. All evaluation outcomes were discounted at an annual rate of 3% and measured over a 10-year planning horizon. Data on the natural history of disease, drug efficacy, patient preferences, and economic costs were obtained from a variety of observational cohorts, randomized trials, and patient surveys. RESULTS: Over a 10-year period, use of inhaled corticosteroids increases total health costs from roughly $5,200 to $8,400 and improves QALYs from 6.8 to 7.0, implying an incremental cost of $13,500 per QALY gained. Costs per symptom-free day gained are $7.50. Both per-person acute exacerbations and hospitalizations are reduced by 33%. The cost-effectiveness findings are sensitive to the assumed efficacy and side-effects of inhaled corticosteroid therapy. CONCLUSIONS: Inhaled corticosteroids appear to deliver good comparative value in adults with mild-to-moderate asthma. Although more research is needed to understand their impact on preferences regarding side effects and compliance, these findings might be useful for priority-setting in limited resource situations.

Bayesian value-of-information analysis. An application to a policy model of Alzheimer's disease.

A framework is presented that distinguishes the conceptually separate decisions of which treatment strategy is optimal from the question of whether more information is required to inform this choice in the future. The authors argue that the choice of treatment strategy should be based on expected utility, and the only valid reason to characterize the uncertainty surrounding outcomes of interest is to establish the value of acquiring additional information. A Bayesian decision theoretic approach is demonstrated through a probabilistic analysis of a published policy model of Alzheimer's disease. The expected value of perfect information is estimated for the decision to adopt a new pharmaceutical for the population of patients with Alzheimer's disease in the United States. This provides an upper bound on the value of additional research. The value of information is also estimated for each of the model inputs. This analysis can focus future research by identifying those parameters where more precise estimates would be most valuable and indicating whether an experimental design would be required. We also discuss how this type of analysis can also be used to design experimental research efficiently (identifying optimal sample size and optimal sample allocation) based on the marginal cost and marginal benefit of sample information. Value-of-information analysis can provide a measure of the expected payoff from proposed research, which can be used to set priorities in research and development. It can also inform an efficient regulatory framework for new healthcare technologies: an analysis of the value of information would define when a claim for a new technology should be deemed substantiated and when evidence should be considered competent and reliable when it is not cost-effective to gather any more information.

The case for daily dialysis: its impact on costs and quality of life.

Research suggests daily hemodialysis may improve clinical outcomes. To date, a comprehensive review of its implications on quality of life has not been performed, and little is known about its economic impact. We conducted an economic evaluation comparing short daily or nocturnal hemodialysis with thrice-weekly conventional in-center dialysis. Data on the quality of life and clinical effects of daily dialysis were obtained from more than 60 reports from 13 daily dialysis programs around the world (n = 197). Cost data were derived principally from the US Renal Data System, Centers for Disease Control, and Medicare Payment Advisory Commission. Resource use during daily hemodialysis was modeled after two ongoing programs in the United States. Results suggest that patients feel better and direct treatment costs could be reduced with daily dialysis. Costs are sensitive to assumptions about the effect of daily dialysis on hospital days. Reductions of at least 8% in hospital days are required for these modalities to be cost saving compared with documented reductions of 30% to 100%. Larger well-controlled studies of daily versus conventional dialysis would be helpful to determine whether daily dialysis fulfills these promises. Medicare policy, which limits payment for most patients to three dialysis treatments weekly, poses a disincentive to more widespread adoption among dialysis centers. Given this constraint to broader acceptance, we address several policy options to gain a better understanding of the potential risks and benefits of daily dialysis.

Effectiveness of chemotherapy for advanced lung cancer in the elderly: instrumental variable and propensity analysis.

PURPOSE: To compare the effectiveness of chemotherapy given to elderly patients in routine practice for stage IV non-small-cell lung cancer (NSCLC) with the efficacy observed in randomized trials. PATIENTS AND METHODS: We used instrumental variable analysis (IVA) and propensity scores (PS) to simulate the conditions of a randomized trial in a retrospective cohort of patients over age 65 from the Survival, Epidemiology, and End Results (SEER) tumor registry. Geographic variation in chemotherapy use served as the instrument for the IVA analysis, and propensity scores were calculated with a logistic model based on patient disease and sociodemographic characteristics. RESULTS: Among 6,232 elderly patients, the instrumental variable estimate indicated an increase in median survival of 33 days and an improvement in 1-year survival of 9% attributable to chemotherapy. In a Cox regression model, chemotherapy administration was associated with a hazard ratio of 0.81 (95% confidence interval, 0.76 to 0.85). When survival was analyzed separately within propensity score quintiles, the hazard ratios were all similar, ranging from 0.78 to 0.85. These results are comparable with those of a large meta-analysis, which found a hazard ratio of 0.87 in the subgroup of patients over age 65. CONCLUSION: Chemotherapy for stage IV NSCLC seems to have effectiveness for elderly patients and those with comorbid conditions that is similar to the efficacy seen in randomized trials containing mostly younger, highly selected patients. All suitable patients should be given the opportunity to consider palliative chemotherapy for metastatic NSCLC.

FEV(1) is associated with risk of asthma attacks in a pediatric population.

BACKGROUND: FEV(1) is endorsed by the National Asthma Education and Prevention Program as a means for grading asthma severity. However, few data exist on the relationship between FEV(1) and asthma outcomes during long-term follow-up. OBJECTIVE: We explored the relationship between the percent predicted FEV(1) (FEV(1)%) and subsequent asthma attacks in a longitudinal study of pediatric lung health. METHODS: A retrospective cohort of 13,842 children (100,292 observations) seen annually over a 15-year interval was analyzed for measurement of pulmonary function, and a respiratory questionnaire was completed. Up to grade 9, a standard questionnaire was completed by a parent or guardian; thereafter it was completed by the patient. For each observation, the report of an attack during the past year was paired with FEV(1) recorded at the field survey 1 year earlier. RESULTS: A progressive decrease in the proportion of individuals reporting an attack was associated with increasing decile of FEV(1)%. Two categorization schemes for FEV(1)% were examined: a scheme based on the National Asthma Education and Prevention Program recommendations (<60%, 60%-80%, and >80%), and an alternative scheme (<80%, 80%-100%, and >100%). In multivariate models, FEV(1)% was an independent predictor of attacks: among the parental report group, the odds ratios were 2.1 (95% CI, 1.3-3.4) and 1.4 (95% CI, 1.2-1.6) for FEV(1)% < 60% and FEV(1)% of 60% to 80% compared with FEV(1)% > 80%, respectively; and among the self-report group, odds ratios were 5.3 (95% CI, 2.2-12.9) and 1.4 (95% CI, 1.2-1.7) for FEV(1)% < 60% and FEV(1)% of 60% to 80% compared with FEV(1)% > 80%, respectively. With the alternative classification scheme, the relationship was similar, but the difference in risk between categories of FEV(1)% decreased. CONCLUSION: The strong association between FEV(1)% and risk of asthma attack over the subsequent year supports an emphasis on objective measures of lung function in assessment of risk for adverse asthma outcomes.

The use of proxy respondents in studies of older adults: lessons, challenges, and opportunities.

OBJECTIVE: Proxies play a critical role as sources of health information for older persons with cognitive impairment and other chronic debilitating conditions. This paper reviews the validity of proxy responses for people older than age 60 in the following areas: functioning, physical and mental health, cognition, medical care utilization, and preferences for types of care and health states. DESIGN: A Medline review identified 24 clinical studies from 1990 to 1999 that use proxy data as a source of information about older adults. RESULTS: In general, studies report fairly good agreement between subjects and proxies in assessments of functioning, physical health, and cognitive status, and fair-to-poor agreement in assessments of psychological well-being. Proxies tend to describe more impairment in functioning and emotional well-being, relative to subjects, a pattern that is particularly marked among persons with cognitive impairment. In addition, proxies who report more caregiver responsibilities and subjective stress from caregiver duties provide more negative assessments of subjects' health and well-being. CONCLUSIONS: Findings tend to support the use of proxy ratings among older adults in many areas but not all when self-reports are not feasible. There is a need for more evaluation of proxy data in relation to other measures, such as performance assessments, medical records, and claims data, which may be less subject to respondent biases.

A comparison of HUI2 and HUI3 utility scores in Alzheimer's disease.

PURPOSE: The Health Utilities Index (HUI) is a generic, multiattribute, preference-based health-status classification system. The HUI Mark 3 (HUI3) differs from the earlier HUI2 by modifying attributes and allowing more flexibility for capturing high levels of impairment. The authors compared HUI2 and HUI3 scores of patients with Alzheimer's disease (AD) and caregivers, and contrasted results of a cost-effectiveness analysis of new drugs for AD using the two systems. METHODS: In a cross-sectional study of 679 AD patient/caregiver pairs, stratified by patient's disease stage (questionable/mild/moderate/severe/profound/terminal) and setting (community/assisted living/nursing home), caregivers completed the combined HUI2/HUI3 questionnaire as proxy respondents for patients and for themselves. RESULTS: Mean (SD) global utility scores for patients were lower on the HUI3 (0.22[0.26]) than on the HUI2 (0.53 [0.21]). Patient HUI3 utility scores ranged from 0.47(0.24) for questionable AD to -0.23 (0.08) for terminal AD, compared with a range of 0.73 (0.15) to 0.14 (0.07) for the HUI2. Among the 203 patients in the severe, profound, and terminal stages, 96 (48%) had negative global HUI3 utility scores, while none had a negative HUI2 score. The utility scores for caregivers were similar on the HUI3 (0.87 [0.14]) and HUI2 (0.87 [0.11]). Cost-effectiveness analysis of a new medication to treat AD showed somewhat more favorable results using the HUI3. CONCLUSIONS: The HUI2 and HUI3 discriminate well across AD stages. Compared with the HUI2, the HUI3 yields lower global utility scores for patients with AD, and more scores for states judged worse than dead. The HUI3 may yield substantially different results from the HUI2, particularly for persons who have serious cognitive impairments such as AD.

A comprehensive league table of cost-utility ratios and a sub-table of "panel-worthy" studies.

OBJECTIVES: The authors compiled a comprehensive league table of cost/QALY ratios, and a standardized table of analyses satisfying selected Reference Case criteria from the USPHS Panel on Cost-Effectiveness in Health and Medicine. METHODS: They identified 228 cost-utility analyses (CUAs) through literature searches, and abstracted data on methods and cost-utility ratios. The subset of "Panel-worthy" analyses used: a societal or broad health-care perspective, community or patient preference weights, net costs, incremental comparisons, and discounting of costs and QALYs. RESULTS: The 228 CUAs included ratios for 647 interventions, ranging from cost-saving to $52,000,000/QALY (median = $12,000/QALY). The standardized table presents 112 ratios that met the "Panel-worthy" criteria, with articles published in recent years more likely to meet all of the criteria. CONCLUSIONS: The comprehensive league table (available on the Web) provides a useful reference, but ratios may not be comparable because of methodologic variations. The standardized table focuses on studies meeting basic methodologic criteria, potentially allowing for better comparison with future Reference Case analyses. Future studies should investigate the quality of analyses' underlying assumptions in addition to whether certain key procedural protocols were met.

Cost-effectiveness of functional imaging tests in the diagnosis of Alzheimer disease.

PURPOSE: To evaluate the cost-effectiveness of functional neuroimaging in the work-up of patients at specialized Alzheimer disease clinics. MATERIALS AND METHODS: A decision model was used to calculate costs and benefits (in quality-adjusted life-years [QALYs]) that accrued to hypothetical cohorts of patients at presentation to an Alzheimer disease center. Sensitivity analysis was performed to examine the effects of diagnostic test characteristics, therapeutic efficacy, disease severity, and costs on cost-effectiveness. RESULTS: The incremental cost-effectiveness ratio of dynamic susceptibility contrast material-enhanced magnetic resonance (MR) imaging was $479,500 per QALY (compared with the usual diagnostic work-up), while visual or quantitative single photon emission computed tomography (SPECT) was dominated (higher costs, lower effectiveness) by the usual diagnostic work-up. These results depend critically on the sensitivity and specificity of the standard diagnostic work-up, the effectiveness of drug treatment, and the disease severity. Varying these parameters resulted in estimates of incremental cost-effectiveness for dynamic susceptibility contrast-enhanced MR imaging of $24,680 to $8.6 million per QALY. SPECT either was dominated by the usual diagnostic work-up or had cost-effectiveness ratios of $180,200 to $6 million per QALY. CONCLUSION: The addition of functional neuroimaging to the usual diagnostic regimen at Alzheimer disease clinics is not cost-effective given the effectiveness of currently available therapies.