|Year : 2015 | Volume
| Issue : 1 | Page : 1-2
Health technology assessment: A bird's eye view
Praveen Kulkarni1, Prashant Vishwanath2
1 Department of Community Medicine, JSS Medical College, JSS University, Mysore, Karnataka, India
2 Department of Biochemistry, JSS Medical College, JSS University, Mysore, Karnataka, India
|Date of Web Publication||13-Jan-2015|
Department of Community Medicine, JSS Medical College, JSS University, Mysore, Karnataka
Source of Support: None, Conflict of Interest: None
|How to cite this article:|
Kulkarni P, Vishwanath P. Health technology assessment: A bird's eye view. Int J Health Allied Sci 2015;4:1-2
"Health and medical service is a finite resource for an infinite demand."
-WHO Annual World Health Report 2010
Cost of illness and health care are leading over 100 million people globally into poverty every year. In some countries, 5% of the population is forced into poverty every year because they have to pay for health services. As per World Health Organization, in countries like India, people who pay for their health care services suffer "catastrophic costs." While millions suffer and die in the absence of access or inability to afford medical care, many others suffer because they end up paying through borrowing debts and selling assets, etc., Unlike developed countries, health policy formulation in developing countries encompasses far more complex areas of intervention besides direct medical care and infrastructure such as primary education, poverty alleviation, sanitation, housing, insurance, etc. Unarguably the funds available for this scope of health care spending are extremely scarce, and the ability to utilize them wisely and economically is absolutely necessary. 
Health technology is defined as anything that is used with the aim of improving a person's health (drug, diagnostic test, screening program, medical protocol, nursing procedure, etc). Health technology assessment (HTA) provides a broad perspective on the evaluation of new or existing health technologies that in principle can cover every activity in health care that is patient orientated, from individual patient interventions such as a specific drug to disease management and population-based care programs, in order to provide decision makers necessary information.
Health technology is often used as a synonym to economic evaluation, which is not true. HTA is a multi-disciplinary, scientific based assessment of technologies in healthcare that examines short- and long-term consequences of the application of a health care technology. The goal is to provide policymakers with information on policy alternatives. On the other hand, economic evaluation is a branch of HTA, as, for instance, epidemiological, judicial, ethical, and social aspects. Economic evaluation looks at the costs and effects of (new) interventions. 
A complete economic evaluation is a one that compares two or more alternatives like intervention and no intervention (study and control) groups in terms of costs (inputs) and effects (outcomes). This can be achieved by one of the four techniques namely cost minimization analysis, cost benefit analysis, cost effective analysis and cost-utility analysis.
In cost minimization analysis always effects are considered equal, and only costs are compared across groups. Cost benefit analysis measures outcome in terms of monetary terms that is not always possible in health services as health cannot be measured directly in terms of money lost or gained. The possible solution for this is cost effective analysis where the outcome is measured in terms of improvement in quality of life, lives saved, deaths prevented, disease averted and complications avoided. This is more desirable method of HTA as the actual effect of the intervention is assessed in this approach. 
The most interesting and widely used method of cost-utility analysis expresses the value for money in terms of a single type of health outcome. The incremental cost-effectiveness ratio in this case is usually expressed as the incremental cost to gain an extra quality-adjusted life-year (QALY). This approach incorporates both increases in survival time (extra life-year) and changes in quality of life (with or without increased survival) into one measure. An increased quality of life is expressed as a utility value on a scale of 0 (dead) to one (perfect quality of life). An increased duration of life of 1 year (without change in quality of life), or an increase in quality of life from 0.5 to 0.7 utility units for 5 years, would result in a gain of one QALY. This allows for easy comparison across different types of health outcome but still requires value judgments to be made about increases in the quality of life (utility) associated with different health outcomes. The use of incremental cost-utility ratios enables the cost of achieving a health benefit by treatment with a drug to be assessed against similar ratios calculated for other health interventions (e.g. surgery or screening by mammography). It, therefore, provides a broader context in which to make judgments about the value for money of using a particular drug. 
Various methods available for assessing the utilities are, rating scale (self-rating of his health status by the subject in a scale of 0-100), standard gamble (to gamble between probabilities of perfect health and instant death across interventions) and time trade off (health raters, who are usually patients encountering or at risk of facing a particular health state, make decisions about how much time in good health they would ''trade off'' to equal a longer time period with a lesser health state). All these methods have several advantages and disadvantages in themselves, but standard gamble gives a better representation of quality perception by the patients. 
Economic evaluation of an intervention can be performed in either of two ways namely trial-based economic evaluation and model-based economic evaluation. In trial-based economic evaluation, the utilities gained across two wings of intervention are assessed against the costs incurred. This method is similar to randomized control trial in epidemiological research. Much commonly used ones are the model-based economic evaluation methods. These methods represent the probabilities of occurrence of an event in real life situation considering the alternatives and time period into account. There are three methods of model-based economic evaluation namely, decision tree model, state transition model, and discrete event simulation models.
Decision tree model even though much easier to understand doesn't explicitly consider time and discounting into account. Model with much wider application is state transition model where health status that are mutually exclusive and collectively exhaustive are listed, and the transition probabilities of a subject between different status are calculated and interpreted with respect to QALY. Discrete event simulation model is much complex to design, and they play between time and event. These models consider entity, attributes, and events and establish mutual relationships between each of them. 
Principles of HTA can be effectively utilized in fixing costs at hospitals. Now-a-day, it is a common practice to fix the charges in hospitals by considering the probability of maximum risk of the disease. This approach may prove burdensome for the patients hailing from lower and middle socioeconomic strata as majority of them spend out of pocket. On the other hand, using the methods of health technology, it is possible to weigh the risk of disease, complications, and death against the interventions and decide the pricing accordingly. This makes the health care costs more flexible leading the increased affordability and utilization of health care services.
Even though these methods of HTA seem to be too complex and hard to use, they yield very satisfying and foresighted results. These methods can be effectively utilized to assess the economic effect of various health intervention programs and procedures at individual, societal and health service sectors. These methods truly help in decision-making process for policy to provide the best health services at reasonable cost in order to gain higher amount of utilities. HTA is a specialty in itself for the young research scholars who are interested in finding their career in health economics.
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