United States National Library of Medicine National Institutes of Health

HTA 101: Introduction to Health Technology Assessment

Technological innovation has yielded truly remarkable advances in health care during the last three decades. In just the last several years, breakthroughs in such areas as antivirals, biotechnology, diagnostic imaging, molecular diagnostics, organ and tissue replacement, surgical techniques, wound care, and computer technology have helped to improve health care delivery and patient outcomes.

The proliferation of health care technology has accompanied burgeoning health care costs, and the former has been cited as "culprit" for the latter. However, the nature and strength of this relationship are complex and evolving (Cutler 2001; Medicare Payment Advisory Commission 2001; Newhouse 1992). Certainly, few patients or clinicians are willing to forego access to state-of-the-art health care technology. In the wealthier countries, and particularly in the US, adoption and use of technology has been stimulated by patient and physician incentives to seek any potential health benefit with limited regard to cost, and by third-party payment, malpractice concerns, provider competition and effective marketing of technologies. Some of the main factors that influence the development and demand for health technology are shown in Box 1.

Box 1
Factors That Reinforce the Market for Health Technology

In this era of increasing cost pressures, restructuring of health care delivery and payment, and continued inadequate access to care for tens of millions in the US and many more millions around the world, technology remains the substance of health care. Culprit or not, technology can be managed in ways that improve patient access and health outcomes, while continuing to encourage innovation. The development, adoption, and diffusion of technology is increasingly mediated by a widening group of policymakers in the health care sector. Health product makers, regulators, clinicians, patients, hospital managers, payers, government leaders, and others increasingly demand well-founded information to support decisions about whether or how to develop technology, to allow it on the market, to acquire it, to use it, to pay for its use and more. The growth and development of health technology assessment (HTA) in government and the private sector reflect this demand.

HTA methods are evolving and their applications are increasingly diverse. This document introduces fundamental aspects and issues of a dynamic field of inquiry. Broader participation of people with multiple disciplines and different roles in health care is enriching the field. The heightened demand for health technology assessment, in particular from the for-profit and not-for-profit private sectors as well as from government agencies, is pushing the field to evolve keener assessment processes and audience-specific reports. Like the information required to conduct most assessments, the body of knowledge about HTA cannot be found in one place and is not static. Practitioners and users of HTA should not only monitor changes in the field, but have considerable opportunities to contribute to its development.

Origins of Technology Assessment

Technology assessment (TA) arose in the mid-1960s from an appreciation of the critical role of technology in modern society and its potential for unintended, and sometimes harmful, consequences. Experience with the side effects of a multitude of chemical, industrial and agricultural processes, and such services as transportation, health, and resource management contributed to this understanding. Early assessments concerned such topics as offshore oil drilling, pesticides, automobile pollution, nuclear power plants, supersonic airplanes, and the artificial heart. TA was conceived as a way to identify the desirable first-order, intended effects of technologies as well as the higher-order, unintended social, economic and environmental effects (Brooks and Bowers 1970).

The term "technology assessment" was introduced in 1965 during deliberations of the Committee on Science and Astronautics of the US House of Representatives. Congressman Emilio Daddario emphasized that the purpose of TA was to serve policymaking:

[T]echnical information needed by policymakers is frequently not available, or not in the  right form. A policymaker cannot judge the merits or consequences of a technological program within a strictly technical context. He has to consider social, economic, and legal implications of any course of action (US Congress, House of Representatives 1967).

Congress commissioned independent studies by the National Academy of Sciences, the National Academy of Engineering (NAE), and the Legislative Reference Service of the Library of Congress that significantly influenced the development and application of TA. These studies and further congressional hearings led the National Science Foundation to establish a TA program and, in 1972, Congress to authorize the congressional Office of Technology Assessment (OTA), which was founded in 1973, became operational in 1974, and established its health program in 1975.

Many observers were concerned that TA would be a means by which government would impede the development and use of technology. However, this was not the intent of Congress or of the agencies that conducted the original TAs. In 1969, an NAE report to Congress emphasized that: Technology assessment would aid the Congress to become more effective in assuring that broad public as well as private interests are fully considered while enabling technology to make the maximum contribution to our society's welfare (National Academy of Engineering 1969).

With somewhat different aims, private industry used TA to aid in competing in the marketplace, for improving understanding of the future business environment, and for producing options for internal and external decisionmakers.

TA methodology drew upon a variety of analytical, evaluative and planning techniques. Among these were systems analysis, cost-benefit analysis, consensus methods (e.g., Delphi method), engineering feasibility studies, clinical trials, market research, technological forecasting, and others. TA practitioners and policymakers recognized that TA is evolving, flexible, and should be tailored to the task (US Congress, Office of Technology Assessment 1977).

Early Health Technology Assessment

Health technologies had been studied for safety, effectiveness, cost, and other concerns long before the advent of HTA. Development of TA as a systematic inquiry in the 1960s and 1970s coincided with the introduction of health technologies that prompted widespread public interest in matters that transcended their immediate health effects. Health care technologies were among the topics of early TAs. Multiphasic health screening was one of three topics of "experimental" TAs conducted by the NAE at the request of Congress (National Academy of Engineering 1969). In response to a request by the National Science Foundation to further develop the TA concept in the area of biomedical technologies, the National Research Council conducted TAs on in vitro fertilization, predetermination of the sex of children, retardation of aging, and modifying human behavior by neurosurgical, electrical or pharmaceutical means (National Research Council 1975). The OTA issued a report on drug bioequivalence in 1974, and the OTA Health Program issued its first formal report in 1976.

Since its early years, HTA has been fueled in part by emergence and diffusion of technologies that have evoked social, ethical, legal, and political concerns. Among these technologies are contraceptives, organ transplantation, artificial organs, life-sustaining technologies for critically or terminally ill patients, and, more recently, genetic testing, genetic therapy, and stem cell research. These technologies have challenged certain societal institutions, codes, and other norms regarding fundamental aspects of human life such as parenthood, heredity, birth, bodily sovereignty, freedom and control of human behavior, and death (National Research Council 1975).

Despite the comprehensive approach originally intended for TA, its practitioners recognized early on that "partial TAs" may be preferable in circumstances where selected impacts are of particular interest or where necessitated by resource constraints (US Congress, Office of Technology Assessment 1977). In practice, relatively few TAs have encompassed the full range of possible technological impacts; most focus on certain sets of impacts or concerns, depending upon who conducts the assessment and what data and other resources are available for the assessment. Although there have been important instances of comprehensive HTAs, partial ones have been typical (Goodman 1992).

Box 2 shows various definitions of TA and HTA.

Box 2
Some Definitions of TA and HTA

We shall use the term assessment of a medical technology to denote any process of examining and reporting properties of a medical technology used in health care, such as safety, efficacy, feasibility, and indications for use, cost, and cost-effectiveness, as well as social, economic, and ethical consequences, whether intended or unintended (Institute of Medicine 1985).

Technology assessment (TA) is a category of policy studies, intended to provide decision makers with information about the possible impacts and consequences of a new technology or a significant change in an old technology. It is concerned with both direct and indirect or secondary consequences, both benefits and disbenefits, and with mapping the uncertainties involved in any government or private use or transfer of a technology.TA provides decision makers with an ordered set of analyzed policy options, and an understanding of their implications for the economy, the environment, and the social, political, and legal processes and institutions of society (Coates 1992).

Technology assessment is a form of policy research that examines short- and long-term social consequences (for example, societal, economic, ethical, legal) of the application of technology. The goal of technology assessment is to provide policy-makers with information on policy alternatives (Banta 1993).

Health technology assessment considers the effectiveness, appropriateness and cost of technologies. It does this by asking four fundamental questions: Does the technology work, for whom, at what cost, and how does it compare with alternatives? (UK National Health Service R&D Health Technology Assessment Programme 2003)

Health technology assessment ... is a structured analysis of a health technology, a set of related technologies, or a technology-related issue that is performed for the purpose of providing input to a policy decision (U.S. Congress, Office of Technology Assessment 1994).

An [HTA] describes: about the technology and its use, which technology is clinically effective, for whom, how it compares with current treatments, [and] at what cost (Canadian Coordinating Office for Health Technology Assessment, 2002)

[HTA] is a multidisciplinary field of policy analysis. It studies the medical, social, ethical, and economic implications of development, diffusion, and use of health technology (International Network of Agencies for Health Technology Assessment 2002).


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Last reviewed: 08 September 2008
Last updated: 08 September 2008
First published: 19 August 2004
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