moving target problem
Changes in health care that can render health technology assessments out-of-date, sometimes even before the recommendations that come out of them can be implemented.
Note: Included are changes in the mother technology, in one of its variants or in a complementary technology (used to treat a given health problem), emergence of new competing technologies, and changes in the application of a technology (e.g. to different patient populations or to different health problems).
Alternative spelling: moving-target problem