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An alternative to obtaining
utilities directly from patients is to obtain them from the literature.
Published utilities are the usual source for the base case analysis
of decision models. Because of the ever-increasing number of journal
articles reporting utilities, it is not possible to provide here
a comprehensive list of diseases for which utilities have been
published.
Some investigators
have attempted to take steps toward developing a national repository
of quality-of-life weights to aid cost-effectiveness analysis.
Tengs and Wallace gathered 1,000 health-related quality of life
estimates from published sources (Tengs
and Wallace, 2000). They noted that there was considerable
variation in the weights assessed for the same health state by
different studies.
The Harvard Center for Risk Analysis
group has reviewed a large number of published cost-utility studies
and developed a catalog of preference scores (Bell,
Chapman et al. 2001), available on a website: http://www.hsph.harvard.edu/cearegistry/.
The Beaver Dam Health
Outcomes Study provides a catalog of health status and utilities,
grouped by various disease conditions (Fryback,
Dasbach et al. 1993). Interviews conducted with 1356 subjects,
ages 43-84, provided data on SF-36, QWB, and a TTO measure of
utility for current health. The Beaver Dam study provides extensive
and valuable data on the self-reported health status and the utility
for current health of a general adult population in Wisconsin,
and a quantitative link between scales (Fryback,
Lawrence et al., 1997). The Beaver Dam utilities are useful
for many other studies; however, this source has some limitations.
It provides utilities by disease status rather than by detailed
functional status and so it does not, for example, provide utilities
necessary for study of the frail elderly. Additionally, the study
population was 99.6% white.
Investigators using
published utilities should consider the quality of the utility
elicitation. As with application of clinical trial evidence
and other forms of evidence, investigators using published utilities
should consider the applicability of the published utilities to
the task or the population under consideration. For example, very
few published utility surveys have included large numbers of individuals
from different socioeconomic and ethnic backgrounds.
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