While some forms of genetic testing have been available for decades, the pr
ogress of the Human Genome Project will expand the possibilities for testin
g. Evaluation of genetic testing is warranted because health care services
have an opportunity cost and thus the benefits of testing must be assessed
against the costs. However, genetic testing raises new methodological diffi
culties in taking into account the full range of costs, benefits and risks.
The conventional approach to evaluating new technologies is to assess thei
r benefits in terms of health outcomes only, and to consider the effects on
the individuals being tested. Like any test, the product of genetic testin
g is information. Any subsequent health outcome gain depends on the effecti
veness of any intervention which results from the information. Assessing th
e benefits in terms of health outcomes only excludes consideration of any v
alue, both positive and negative, attached to information. The special feat
ure of genetic testing is that the information obtained has implications fo
r family members. This information may have value to relatives individually
and may affect family interactions. Information also has value at a social
level; it may affect social relationships and interactions. As the possibi
lities for genetic testing expand, it is likely that testing programs will
be subject to economic evaluation. Until the methods and measures used can
validly take this range of effects into account (and into a count of benefi
ts), then the results of evaluation studies will be, at best, incomplete an
d, at worst, misleading.