Evolution toward revolution.

Evolution toward Revolution

Technology assessments are assuming an increasing importance in this era of both rapidly moving technology capabilities and rising health care costs. Individual physicians can use technology assessments to determine which technologies would be of value to their practices. Practice guidelines use technology assessments as their scientific base. Third-party payers increasingly depend on technology assessments to determine coverage eligibility. Because technology assessments have a tremendous potential to influence the diffusion of a new technology, it is vital that an assessment accurately reflect the state of knowledge about a specific technology.

Technologies are not static but have life cycles. One can envision a technology life cycle as a U-shaped curve, with the x-axis representing status and the y-axis representing the degree of knowledge about the technology (see accompanying figure). When a technology is introduced, it starts out at the bottom of this curve and is considered investigational. As more experience and data accumulate, the technology can move up one of the curve's arms. If the data validate its safety and effectiveness, the technology moves up the established arm. If the incoming data are negative, the technology moves up the unacceptable arm.

Which points on the curve represent the transition from investigational to either established or unacceptable depends somewhat on the technology, the availability of alternatives, and the severity of illness. For example, an investigational technology may still be the most appropriate treatment for a terminally ill patient who has exhausted all other treatment options.

The movement of a technology along this U-shaped curve is a slow, gradual process. The transition from investigational to established does not happen over night. The challenge of technology assessments, then, is to devise a system that most accurately reflects technology's evolution.

The DATTA (Diagnostic and Therapeutic Technology Assessment) program has recently modified its methodology to address this issue. Previously, a panel of expert physicians was routinely asked to respond to specific safety and effectiveness questions about a technology by rating the technology as either established, investigational, unacceptable, or indeterminate. Essentially, these categories identified only the initial starting point and the two end points of the technology life cycle curve. There was no way to indicate that a technology might be somewhere in between the end points. The indeterminate rating did not indicate on which side of the curve the technology was located.

One new method considered was reproducing the life cycle curve and asking physicians to assign the technology to a specific point. In essence, this method would produce an infinite number of possible ratings and thus would be too difficult to evaluate quantitatively. Instead, two categories were added to the rating system, "promising" and "doubtful." The definition of promising is "Given current knowledge, the safety and effectiveness of this technology appears to be appropriate for the given indication in the specified patient population. As more experience and long-term follow-up are accumulated, this interim rating will change." Doubtful is defined: "Given current knowledge, the safety and effectiveness appears to be inappropriate for the given indication in the specified patient population. As more experience and long-term follow-up are accumulated, this interim rating will change." The indeterminate category was eliminated. While not a perfect solution, the expansion of the ratings does provide a way to indicate that a technology is at an indeterminate point in its life cycle and reflects its potential value or risk for specific patient populations.

The second recent focus of the DATTA program has been reassessments of existing technologies. Reassessments are undertaken whenever DATTA staff members believe that the status of a technology has changed. The DATTA methodology is ideally suited to reassessments. With a qualitative analytic approach using expert medical opinion and literature reviews, a rapid turnaround of DATTA avaluations (about six months from inception to publication in JAMA) has been achieved. This year, the DATTA program is reevaluating autologous bone marrow transplantation, percutaneous diskectomy, and transrectal ultrasound of the prostate.

The DATTA methodology will continue to evolve as the program moves to comparing the safety and effectiveness of two or more technologies, or strives to identify obsolete technologies. The overall purpose will remain the same: to provide timely and practical evaluations that will assist physicians in their practices and represent their views to third party-payers and public policy makers.

Elizabeth Brown, MD, is Director, Department kb Technology Management, American Medical Association, Chicago, Ill.