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HTA 101: Introduction to Health Technology Assessment Questions and Answers

1.  I have read that a problem with the QALY is that it can discriminate against those with existing disabilities/conditions.  In your opinion, how does the QALY compare to the DALY?

QALYs, disability-adjusted life years (DALYs), and healthy-years equivalents (HYEs) are measures of health improvement (or loss) that combine survival and morbidity (including health status, quality of life, or functional status) into a single unit.  One of the main reasons for using such combined or “hybrid” measures is to enable comparisons of the impact of health technologies or other changes (e.g., environmental or economic) where the outcomes (other than survival) are not the same, e.g., incidence of diabetes, reduction in heart attacks, or prevalence of tobacco use.  These measures are based on somewhat different assumptions and methods (e.g., for determining quality of life and disability).  QALYs tend to be used more often in cost utility analyses to determine the ratio of cost to QALYs gained from using a particular health care technology.  DALYs tend to be used more often in public health to measure population disease burden and impact of health programs on population health.  These measures are not interchangeable, and their differences should be considered when designing and interpreting studies using these measures.   Although their main purposes are similar, one is not inherently better than the others; one may be more suitable than the others for particular circumstances.  See, e.g.:

Gold MR, Stevenson D, Fryback DG. HALYS and QALYS and DALYS, oh my: similarities and differences in summary measures of population health. Annu Rev Public Health 2002;23:115-34.

Fox-Rushby JA, Hanson K. Calculating and presenting disability adjusted life years (DALYs) in cost-effectiveness analysis. Health Policy Plan 2001;16(3):326-31.

Sassi F. Calculating QALYs, comparing QALY and DALY calculations. Health Policy Plan 2006;21(5):402-8.

2.  Do you know if there is a difference between health tech assessment and health tech appraisal?

HTA is conducted in different ways, including with greater or lesser scope and depth.  In some instances, the term “health technology appraisal” is used to refer to parts or nearly all of what comprises HTA.  For example, health technology appraisal may refer to an HTA, or the part of an HTA, that involves the process of formulating guidance or policy advice.  In the UK, the National Institute for Health and Clinical Excellence (NICE) uses the term for “the process of determining the clinical and cost effectiveness of a health technology,” adding that “NICE health technology appraisals are designed to provide patients, health professionals and managers with an authoritative source of advice on new and existing health technologies.”

3. HTA helps us to use the best of our resources and money and get the best outcomes for patients, but how we can use it for sustainability of the health care system

Health technology development, diffusion, access, population health impacts, and costs are among the many scientific, epidemiological, social, economic, environmental, and political factors that affect health care system sustainability.  Health care decision-makers and policy-makers can use HTA, along with other inputs, to help inform resource allocation and policies at various levels, including between individual patients and clinicians, in communities, in nations, and at the global level, to contribute to health care system sustainability. 

4. I am wondering that you stress the QALY concept. According to the new U.S legislation, the QALY will not be used in the PCO, Germany reduced its role and UK will skip it as well when introducing value-based pricing in 2014.

QALYs, as well as other measures intended to account for survival adjusted for morbidity (including health status, quality of life, or functional status), serve the continued useful purpose of enabling comparisons among health technologies that have different types of health effects.  QALYs may be less useful when, for example, comparing alternative interventions for treating a particular disease for which there are disease- or condition-specific outcome measures.  However, comparing the benefits of interventions with different types of impacts on health (e.g., incidence of influenza or mobility following stroke) can be served with a common measure that accounts for length of life as well as quality of life.  QALYs, DALYs, and other such combined measures have their respective strengths and weaknesses, and work continues to improve them and better describe appropriate circumstances to use them.  They are regarded as preferable to other measures of health improvement.  Aside from the circumstances in which these measures are not useful, there are others in which political or social concerns limit their use.  When used in cost-utility analysis, comparisons of the cost per QALY gained from different health care interventions can be quite revealing about the relative returns to individual and population health of allocating limited resources.  This application of QALYs is more or less relevant depending on the organization and financing of health care.  For further discussion, see, e.g.:

Neumann PJ, Weinstein MC. Legislating against use of cost-effectiveness information. N Engl J Med 2010; 363:1495-7.

5. Can you say more about the “moving target problem”? 

The moving target problem can arise when the time span between the initiation of an HTA and the dissemination of its findings (and thereafter) coincides with changes that may affect the currency of the HTA findings.  Such changes might include, e.g., those in a technology of interest, the comparator(s), how or where the technology is used or applied, or the indications of a technology, including the patient types (age, sex, comorbidities)or diseases or conditions for which the technology is used.  Managing the moving target problem should recognize that HTA is an iterative, not one-time, process, and that HTA topics should be revisited periodically or based on some other criteria. HTA reports should document their information sources, assumptions, and processes, which provides baseline information that will better enable HTA programs and decision-makers to recognize when it is time for reassessment.  Assessment programs should have (or use from external sources) horizon scanning or monitoring functions to detect important changes in technologies and how they are used.  Another protection against the moving target problem is that, given the variety of health technology decision-makers and their perspectives and needs, and broader use of improved HTA methods, multiple HTAs may be generated over time on same or similar topics. 

6. What is horizon scanning in HTA?

Depending on what information is gathered and how it is used, horizon scanning can be regarded as an input to HTA or as a special form of HTA.  It usually involves rapidly completed, brief descriptions of emerging, new, or changing technologies and their potential impacts.  Horizon scanning can be used to:  identify areas of technological change; identify technologies that have potentially major implications for health care; identify inappropriately used (including under- and over-used) technologies; plan data collection to monitor adoption, use, and impacts; enable health care providers and payers to plan for and adapt to technological change; and manage adoption and use of new technologies.  

Last Reviewed: August 2, 2016