THE PROCESS OF HEALTH TECHNOLOGY ASSESSMENT (HTA)

“Key principles for the improved conduct of health technology assessment for resource allocation decisions.” The title says it all. I am amazed that such a summary is even possible and that it defines this field so well. Perhaps this report will be cited for years to come as the best and central definition of HTA. A field like this can be defined in other ways.

THE SOCIAL CONTEXT OF HTA

Governments and Insurers must decide what care and treatments to pay for. HTA undertakes to answer this perennial question in a reasoned way. Because there is this ongoing need the economic basis for HTA is secure. There will always be funding for this kind of work. It will primarily be carried out by government agencies and by consultants and not so much by academia. HTA answers must be rapid and accurate enough to stand up to challenge.

THEORY AND HTA

Some academic disciplines define themselves by theory. Molecular biology, physics, statistics, and economics come to mind. Some fields like epidemiology are a body of methods devoid of theory. HTA is some where in between. Read that wonderful title again. “. . . for Resource Allocation Decisions.” The implicit theoretical framework here is based on economics and management: resource scarcity, rational choice, the management of innovation, and biostatistics. Theory is important. It allows for generalization, which in turn allows for replication, which is the basis for evidence with in the scientific method. If HTA is primarily a body of methods, then it is this process of assessment not the specific content of any assessment at one moment of time that is repeatable.

THE CHANGING WORLD

HTA exists in a world of change; new evidence about specific therapies and new methods of evaluation. There are four new methods that could radically change this body of methods. These are: “Prognostic Markets” which use stock market methods to create a real-time probabilistic price on the likelihood of a future event. Go to the Web site “Intrade.com” to see the current predictions about who will be the next president of the United States. As of April 18, 2008, at 4:30EST you could buy a future on the event that John McCain is elected president of the United States. If you paid 39.6 cents on McCain and he wins you would get a dollar back. If he looses you got nothing back. This method is used by corporations in their internal planning “Will our new passenger jet be flying with passengers on Dec. 31, 200x?” Such markets could be used to help evaluate medical technologies. “Will a panel of experts say that this drug is effective 1 year from now?” These markets could be used to define the size of co-payments. If there is a price of 70 cents that this drug will be declared effective in 2 years time, the coinsurance payment could be 30 cents.

Another Web site worth contemplating is “Patientslikeme.com” which allows patients to publicly enter their own data and compare their treatments and health status with similar people. They can carry out their own case control studies or indeed their own experiments. As the complexities of human subjects review and approval grind down academic research, this method can bypass academia all together. The reader is strongly urged to check out these two Web sites and contemplate their possible consequences.

As we move to individualized medicine, the traditional randomized trials may diminish in value and be replaced by individual trials of one. The gold standard method here is the factorial experimental design (see Olsson J., et al. The one person randomized controlled trial. Qual Manag Health Care. 2005;14:206-216), For chronic conditions needing lots of data points sequentially over time, home-based monitors combined with cell phone technology will allow such trials to be carried out at home and monitored at a central location.

It is possible that these methods may transform HTA beyond the bounds of this field as defined by the International Working Group's Report.