Multidisciplinary field of policy analysis that studies the medical, social, ethical, and economic implications of the development, diffusion, and use of technologies. In support of national coverage determinations (NCDs), TA often focuses on the safety and efficacy of technologies. Each NCD includes a comprehensive TA process. For some NCDs, external TAs are requested through the Agency for Health Research and Quality (AHRQ). Also referred to as health care technology assessment (HTA) .