摘要:This paper critically discusses two previous studies concerned with predictions of HIV/AIDS in the
United States and Japan during the early 1990s. Although the study in the US applied a historical
theory, assuming normal distribution for the epidemic curve, the underlying infection process was
not taken into account. In the Japan case, the true HIV incidence was estimated using the coverage
ratio of previously diagnosed/undiagnosed HIV infections among AIDS cases, the assumptions of
which were not supported by a firm theoretical understanding. At least partly because of failure to
account for underlying mechanisms of the disease and its transmission, both studies failed to yield
appropriate predictions of the future AIDS incidence. Further, in the Japan case, the importance of
consistent surveillance data was not sufficiently emphasized or openly discussed and, because of
this, revision of the AIDS reporting system has made it difficult to determine the total number of
AIDS cases and apply a backcalculation method. Other widely accepted approaches can also fail to
provide perfect predictions. Nevertheless, wrong policy direction could arise if we ignore
important assumptions, methods and input data required to answer specific questions. The present
paper highlights the need for appropriate assessment of specific modeling purposes and explicit
listing of essential information as well as possible solutions to aid relevant policy formulation.