Assessing medical technology assessment: past, present, and future.

Advances in medical technology have contributed both to the quality of health care and to its costs. The marketplace doesn't produce sufficient information to anticipate either real health or economic value. Formal assessment of new technologies for safety, efficacy, effectiveness, and cost has been unimpressively dominated by government. While new agency and institutional arrangements promise greater success, they will require a balance between public and private sector roles in procedures and financial support.