Prevention, treatment, and palliative care: The relative value of health improvements under alternative evaluation frameworks.

The social value of decreasing health risks can be evaluated using benefit-cost analysis (BCA), cost-effectiveness analysis (CEA), or a social-welfare function (SWF). These frameworks can produce different social preference rankings of interventions depending on how their health effects and costs are distributed in a population. This paper derives social values of marginal decreases in the probability of illness, its severity (decrease in health status), lethality (conditional mortality risk), and cost under BCA, CEA, and three benchmark SWFs: utilitarian, ex ante prioritarian, and ex post prioritarian. The sensitivity of the social values of improvements in health and decreases in cost to individual circumstances are diverse. In contrast, the conditions under which a decrease in risk, severity, or lethality is socially preferred to a decrease in another of these dimensions are identical for BCA, CEA, the utilitarian and ex ante prioritarian SWFs, but can differ for the ex post prioritarian SWF.

The Modest Effects of Fact Boxes on Cancer Screening.

As health care becomes increasingly personalized to the needs and values of individual patients, informational interventions that aim to inform and debias consumer decision-making are likely to become important tools. In a randomized controlled experiment, we explore the effects of providing participants with published fact boxes on the benefits and harms of common cancer screening procedures. Female participants were surveyed about breast cancer screening by mammography, while male participants were surveyed about prostate cancer screening by prostate-specific antigen (PSA) testing. For these screening procedures, we expect consumers to have overly optimistic prior beliefs about the benefits and harms. We find that participants update their beliefs about the net benefits of screening modestly, but we observe little change in their stated preferences to seek screening. Participants who scored higher on a numeracy test updated their beliefs about screening benefits more in response to the fact boxes than did participants who scored lower on the numeracy test.

The value of disease prevention vs treatment.

We present an integrated valuation model for diseases that are life-threatening. The model extends the standard one-period value-per-statistical-life model to three health prospects: healthy, ill, and dead. We derive willingness-to-pay values for prevention efforts that reduce a disease's incidence rate as well as for treatments that lower the corresponding health deterioration and mortality rates. We find that the demand value of prevention always exceeds that of treatment. People often overweight small risks and underweight large ones. We use the rank dependent utility framework to explore how the demand for prevention and treatment alters when people evaluate probabilities in a non-linear manner. For incidence and mortality rates associated with common types of cancers, the inverse-S shaped probability weighting found in experimental studies leads to a significant increase in the demand values of both treatment and prevention.

Risk trade-offs in fish consumption: a public health perspective.

Fish consumption advisories instruct vulnerable consumers to avoid high mercury fish and to limit total fish intake to reduce neurotoxic risk. Consumption data from the U.S. suggest that nontarget consumers also respond to such advice. These consumers reduce exposure to mercury and other toxicants at the cost of reduction in cardioprotective fatty acids. We present a probabilistic model to assess these risk trade-offs. We use NHANES consumption data to simulate exposure to contaminants and nutrients in fish, employ dose-response relationships to convert exposure to health end points, and monetize them using benefit transfer. Our results suggest that newborns gained on average 0.033 IQ points from their mothers' compliance with the prominent FDA/EPA advisory. The welfare gain for a birth cohort is estimated at $386 million. This gain could be fully offset by increments in cardiovascular risk if 0.6% of consumers aged 40 and older reduced fish intake by one monthly meal until they reached the age of 60 or if 0.1% of them permanently reduced fish intake.

Willingness-to-pay for predictive tests with no immediate treatment implications: a survey of US residents.

We assessed how much, if anything, people would pay for a laboratory test that predicted their future disease status. A questionnaire was administered via an internet-based survey to a random sample of adult US respondents. Each respondent answered questions about two different scenarios, each of which specified: one of four randomly selected diseases (Alzheimer's, arthritis, breast cancer, or prostate cancer); an ex ante risk of developing the disease (randomly designated 10 or 25%); and test accuracy (randomly designated perfect or 'not perfectly accurate'). Willingness-to-pay (WTP) was elicited with a double-bounded, dichotomous-choice approach. Of 1463 respondents who completed the survey, most (70-88%, depending on the scenario) were inclined to take the test. Inclination to take the test was lower for Alzheimer's and higher for prostate cancer compared with arthritis, and rose somewhat with disease prevalence and for the perfect versus imperfect test [Correction made here after initial online publication.]. Median WTP varied from $109 for the imperfect arthritis test to $263 for the perfect prostate cancer test. Respondents' preferences for predictive testing, even in the absence of direct treatment consequences, reflected health and non-health related factors, and suggests that conventional cost-effectiveness analyses may underestimate the value of testing.

Economic evaluation of the US Environmental Protection Agency's SunWise program: sun protection education for young children.

OBJECTIVE: The SunWise School Program is a school-based sun safety education program that was developed by the US Environmental Protection Agency and aims to teach children how to protect themselves from overexposure to the sun. The objectives of this study were to assess the health benefits of the SunWise School Program and use economic analysis to determine the program's net benefits and cost-effectiveness. METHODS: Standard cost/benefit and cost-effectiveness analysis methods were used. Intervention costs were measured as program costs estimated to be incurred by the US government, which funds SunWise, using 3 funding scenarios. Health outcomes were measured as skin cancer cases and premature mortalities averted and quality-adjusted life-years saved. These health outcomes were modeled using an effectiveness evaluation of SunWise based on pretest and posttest surveys administered to students who participated in the program and the Environmental Protection Agency's peer-reviewed Atmospheric and Health Effects Framework model. Costs averted were measured as direct medical costs and costs of productivity losses averted as a result of SunWise. Net benefits were measured as the difference between costs averted and program costs. RESULTS: Economic analysis indicated that if the SunWise School Program continues through 2015 at current funding levels, then it should avert >50 premature deaths, nearly 11,000 skin cancer cases, and 960 quality-adjusted life-years (undiscounted) among its participants. For every dollar invested in SunWise, between approximately $2 and $4 in medical care costs and productivity losses are saved, depending on the funding scenario. CONCLUSIONS: From a cost/benefit and cost-effectiveness perspective, it is worthwhile to educate children about sun safety; small to modest behavioral impacts may result in significant reductions in skin cancer incidence and mortality.

Tiered chemical testing: a value of information approach.

In December 2000 the EPA initiated the Voluntary Children's Chemical Evaluation Program (VCCEP) by asking manufacturers to voluntarily sponsor toxicological testing in a tiered process for 23 chemicals selected for the pilot phase. The tiered nature of the VCCEP pilot program creates the need for clearly defined criteria for determining when information is sufficient to assess the potential risks to children. This raises questions about how to determine the "adequacy" of the existing information and assess the need to undertake efforts to reduce uncertainty (through further testing). This article applies a value of information analysis approach to determine adequacy by modeling how toxicological and exposure data collected through the VCCEP may be used to inform risk management decisions. The analysis demonstrates the importance of information about the exposure level and control costs in making decisions regarding further toxicological testing. This article accounts for the cost of delaying control action and identifies the optimal testing strategy for a constrained decisionmaker who, absent applicable human data, cannot regulate without bioassay data on a specific chemical. It also quantifies the differences in optimal testing strategy for three decision criteria: maximizing societal net benefits, ensuring maximum exposure control while net benefits are positive (i.e., benefits outweigh costs), and controlling to the maximum extent technologically feasible while the lifetime risk of cancer exceeds a specific level of risk. Finally, this article shows the large differences that exist in net benefits between the three criteria for the range of exposure levels where the optimal actions differ.

Cost-effectiveness of treatment for chronic hepatitis C infection in an evolving patient population.

CONTEXT: Approximately 2.7 million US individuals are chronically infected with the hepatitis C virus (HCV). As public health campaigns are pursued, a growing number of treatment candidates are likely to have minimal evidence of liver damage. OBJECTIVE: To examine the clinical benefits and cost-effectiveness of newer treatments for chronic hepatitis C infection in a population of asymptomatic, HCV sero-positive but otherwise healthy individuals. DESIGN AND SETTING: Cost-effectiveness analysis using a Markov model of the natural history of HCV infection and impact of treatment. We used an epidemiologic model to derive a range of natural history parameters that were empirically calibrated to provide a good fit to observed data on both prevalence of HCV seropositivity and time trends in outcomes related to HCV infection. PATIENTS: Cohorts of 40-year-old men and women with elevated levels of alanine aminotransferase, positive results on quantitative HCV RNA assays and serologic tests for antibody to HCV, and no histological evidence of fibrosis on liver biopsy. INTERVENTIONS: Monotherapy with standard or pegylated interferon alfa-2b; combination therapy with standard or pegylated interferon plus ribavirin. MAIN OUTCOME MEASURES: Lifetime costs, life expectancy, quality-adjusted life-years (QALYs), and incremental cost-effectiveness ratios. RESULTS: The probability of patients with chronic HCV developing cirrhosis over a 30-year period ranged from 13% to 46% for men and from 1% to 29% for women. The incremental cost-effectiveness of combination therapy with pegylated interferon for men ranged from 26 000 dollars to 64 000 dollars per QALY for genotype 1 and from 10 000 dollars to 28 000 dollars per QALY for other genotypes; and for women ranged from 32 000 dollars to 90 000 dollars for genotype 1 and from 12 000 dollars to 42 000 dollars for other genotypes. Because the benefits of treatment were realized largely in the form of improvements in health-related quality of life, rather than prolonged survivorship, cost-effectiveness ratios expressed as dollars per year of life were substantially higher. Results were most sensitive to assumptions about the gains and decrements in health-related quality of life associated with treatment. CONCLUSIONS: While newer treatment options for hepatitis C appear to be reasonably cost-effective on average, these results vary widely across different patient subgroups and depend critically on quality-of-life assumptions. As the pool of persons eligible for treatment for HCV infection expands to the more general population, it will be imperative for patients and their physicians to consider these assumptions in making individual-level treatment decisions.

Use of expert judgment in exposure assessment: part 2. Calibration of expert judgments about personal exposures to benzene.

The recent movement of regulatory agencies toward probabilistic analyses of human health and environmental risks has focused greater attention on the quality of the estimates of variability and uncertainty that underlie them. Of particular concern is how uncertainty--a measure of what is not known--is characterized, as uncertainty can play an influential role in analyses of the need for regulatory controls or in estimates of the economic value of additional research. This paper reports the second phase of a study, conducted as an element of the National Human Exposure Assessment Survey (NHEXAS), to obtain and calibrate exposure assessment experts judgments about uncertainty in residential ambient, residential indoor, and personal air benzene concentrations experienced by the nonsmoking, nonoccupationally exposed population in U.S. EPA's Region V. Subjective judgments (i.e., the median, interquartile range, and 90% confidence interval) about the means and 90th percentiles of each of the benzene distributions were elicited from the seven experts participating in the study. The calibration or quality of the experts' judgments was assessed by comparing them to the actual measurements from the NHEXAS Region V study using graphical techniques, a quadratic scoring rule, and surprise and interquartile indices. The results from both quantitative scoring methods suggested that, considered collectively, the experts' judgments were relatively well calibrated although on balance, underconfident. The calibration of individual expert judgments appeared variable, highlighting potential pitfalls in reliance on individual experts. In a surprising finding, the experts' judgments about the 90th percentiles of the benzene distributions were better calibrated than their predictions about the means; the experts tended to be overconfident in their ability to predict the means. This paper is also one of the first calibration studies to demonstrate the importance of taking into account intraexpert correlation on the statistical significance of the findings. When the judgments were assumed to be independent, analysis of the surprise and interquartile indices found evidence of poor calibration (P<0.05). However, when the intraexpert correlation in the study was taken into account, these findings were no longer statistically significant. The analysis further found that the experts' judgments scored better than estimates of Region V benzene concentrations simply drawn from earlier studies of ambient, indoor and personal benzene levels in other U.S. cities. These results suggest the value of careful elicitation of expert judgments in characterizing exposures in probabilistic form. Additional calibration studies need to be undertaken to corroborate and extend these findings.

Timing of prophylactic surgery in prevention of diverticulitis recurrence: a cost-effectiveness analysis.

Although surgery is recommended after two or more attacks of uncomplicated diverticulitis, the optimal timing for surgery in terms of cost-effectiveness is unknown. A Markov model was used to compare the costs and outcomes of performing surgery after one, two, or three uncomplicated attacks in 60-year-old hypothetical cohorts. Transition state probabilities were assigned values using published data and expert opinion. Costs were estimated from Medicare reimbursement rates. Surgery after the third attack is cost saving, yielding more years of life and quality adjusted life years at a lower cost than the other two strategies. The results were not sensitive to many of the variables tested in the model or to changes made in the discount rate (0-5%). In conclusion, performing prophylactic resection after the third attack of diverticulitis is cost saving in comparison to resection performed after the first or second attacks and remains cost-effective during sensitivity analysis.

Empirically calibrated model of hepatitis C virus infection in the United States.

This study presents a comprehensive epidemiologic model of hepatitis C in the United States. Through empirical calibration of model parameter values, the objectives were to gain insights into uncertain aspects of the natural history of hepatitis C and to improve the basis for projecting the future course of the epidemic. A systematic review of the published literature was conducted to define plausible ranges around model parameters, and multiple simulations of the model were undertaken using sampled values from these ranges. Model predictions produced by each set of sampled values were compared with available epidemiologic data on infection prevalence and mortality from liver cancer, and various goodness-of-fit criteria were used to identify the range of parameter values that were consistent with these data. The results of the study indicate that rates of progression to advanced liver disease may be lower than previously assumed. The authors also found that a wide range of plausible assumptions about heterogeneity in these rates, beyond that explained by age and sex, is consistent with observed epidemiologic trends. These findings have important implications both for individual clinical decisions and for broader public health policy.