Health technology assessment: a review of international activity and examples of approaches with computed tomographic colonography.

The growth of health technology assessment (HTA) internationally is currently reflected in the growing membership of the International Network of Agencies for Health Technology Assessment. Many national and regional HTA institutions emerged in the 1980s and 1990s, and more recently, HTA has emerged in newly industrialized countries and in European Union member states in transition. Health technology assessment activities are becoming an increasingly important part of health care culture, with the appearance of HTA units in hospitals and hospital departments. This article provides a brief overview of who conducts HTA internationally and looks at how HTA is conducted and how this information is used. To highlight the different structures, processes, and methods available, a portion of this article is dedicated to describing different approaches that have been observed with respect to the assessment of computed tomographic colonography in North America for population-based colorectal cancer screening.