Grantee Research Project Results

2005 Progress Report: Valuing Morbidity Using Willingness to Pay and Health Utility Measures

EPA Grant Number: R831593
Title: Valuing Morbidity Using Willingness to Pay and Health Utility Measures
Investigators: Hammitt, James K. , Haninger, Kevin
Institution: Harvard University
EPA Project Officer: Hahn, Intaek
Project Period: January 15, 2005 through January 14, 2007 (Extended to January 14, 2009)
Project Period Covered by this Report: January 15, 2005 through January 14, 2006
Project Amount: $333,396
RFA: Valuation for Environmental Policy (2003) RFA Text |  Recipients Lists
Research Category: Environmental Justice

Objective:

This project is aimed at improving the valuation of environmental health risks. The broad goal of the work is to determine the feasibility of developing credible and accurate values of reducing morbidity risk that can be widely applied or transferred when estimating the benefits of environmental policies. More specifically, we propose to design and conduct a stated preference survey to examine the following research questions:

1. What is the relationship between willingness to pay (WTP) and quality adjusted life year (QALY) losses for environmental health risks that vary in the duration and severity of symptoms, in the attributes of health that are impaired, and in whether the illness is identified by name? Can changes in health-related quality of life (HRQL) measured by a generic index of health status be used as a proxy for specific morbidity risks?
2. How does the value of reducing morbidity risks to children compare with the value of reducing similar morbidity risks to adults?
3. How does the value of reducing morbidity risks depend on whether the risk reduction is obtained through public or private mechanisms?
4. How does the value of reducing morbidity risks depend on respondent characteristics such as health, age, and wealth?

Progress Summary:

During the reporting period we worked on examining the theoretical relationship between WTP and QALY frameworks and developed questions for the survey instrument. During part of this period, Professor Hammitt visited the University of Toulouse where he collaborated with Nicholas Treich (a consultant to this project) on investigating the theoretical underpinnings of WTP to reduce health risk and developing potential survey questions.

To measure HRQL, we have decided to substitute the EQ-5D generic health utility instrument for the Health Utilities Index (HUI) instrument described in our research application. The EQ-5D is considerably simpler for respondents, as it includes only five attributes with three levels each. In contrast, the HUI includes eight attributes with five or six levels each. In addition to the smaller burden it places on respondents, the EQ-5D has the advantage of a newly developed scoring function (used to predict health-related quality of life from the multiattribute classification) developed for the U.S. population (Shaw, et al., 2006). In contrast, the scoring function for the HUI has been estimated using only a small regional Canadian population. Moreover, the EQ-5D was recommended for use in regulatory analysis by the recent Institute of Medicine panel on measuring health for cost-effectiveness analysis of environmental health and safety regulations.

Knowledge Networks has been selected to field the internet-based survey to its panel of respondents and a subcontract negotiated and signed.

Future Activities:

We currently are drafting the full survey instrument. This will be provided to Knowledge Networks for programming, after which we will check for any programming errors, work with Knowledge Networks to correct these, then field the survey. Subsequently, we will analyze the data using multiple regression models to examine how WTP to reduce health risk varies with severity and duration of illness and other factors, as described in the research objectives. We plan to request a no-cost extension for completion of the work.

Reference:
Shaw JW, Johnson JA, Coons, SJ. US valuation of the EQ-5D health states: development and testing of the D1 valuation model. Medical Care 2005;43:203-220.

Supplemental Keywords:

contingent valuation, benefit-cost analysis, preferences, willingness to pay,, RFA, Scientific Discipline, Economic, Social, & Behavioral Science Research Program, Economics & Decision Making, Ecological Risk Assessment, Health Risk Assessment, Economics, decision-making, Social Science, health utility measures, willingness to pay, belief system, ecosystem valuation, mortality, policy analysis, policy making, environmental decision making, decision analysis, valuation, valuation of mortality, human health risk, morbidity risks, decision making, econometric analysis

Progress and Final Reports:

Original Abstract

2006 Progress Report

2007 Progress Report

Final