"There are some segments of the U.S. population for which health care is publicly financed through tax dollars," said James Shaw, assistant professor of pharmacy administration at UIC and principal investigator of the study. "To guide the financing decisions that affect these groups, it is important to understand how society values health."
Using data from a representative sample of more than 4,000 Americans, Shaw and his colleagues developed a model to predict median preferences for health states described by the EQ-5D questionnaire. The model's predictions, Shaw said, provide "the most accurate and equitable of available representations of U.S. population preferences for EQ-5D health states."
The EQ-5D is a brief questionnaire designed to measure a person's point-in-time health status. It uses five questions to measure the severity of problems with mobility, the performance of self-care activities, the performance of usual activities, pain/discomfort, and anxiety/depression.
Combinations of responses to the questions describe a total of 243 unique health states. An index representing the value of an individual's health to society can be derived by weighting and aggregating his or her questionnaire responses.
Until now, EQ-5D index scores were generated using a set of weights developed to estimate mean societal preferences for EQ-5D health states.
Mean values have traditionally been used to characterize health preferences in the U.S., Shaw said. But, "a handful of individuals with extreme preferences can exert undue influence on the mean. The median provides a fairer representation of the aggregate preference of all population members, as it is influenced to a lesser degree by extreme values."
The research, published in the March/April issue of the journal Value in Health, resolves a number of problems that have plagued previous efforts to estimate population health preferences, Shaw said.
"Our predicted preferences should be considered for use in cost-utility analyses conducted in the United States," Shaw said. "Given the current political environment, this work will hopefully foster an increased interest in the performance of economic evaluations for health care products and services."