the privacy and confidentiality of personal medical information has stimulated legislative reform proposals but no action to date.

Major challenges confront those evaluating clinical applications of telemedicine. These difficulties also characterize many other applications of advanced technologies, and, thus, they are not unique to telemedicine. Nonetheless, the combination of challenges is formidable. They include

• the rapid advance of information and telecommunications technologies, which exposes systematic and often expensive evaluations to obsolescence as key hardware and software components of telemedicine applications move from state of the art to outmoded;
• a complex and often unwieldy technical infrastructure, which may yield disappointing evaluations until it becomes more ubiquitous and user-friendly;
• a diverse and sometimes dazzling array of telemedicine technologies and uses that may distract managers and evaluators from the task of identifying practical, affordable, and sustainable ways to achieve defined quality, access, or cost objectives; and
• the unusual level of cooperation that medicine at a distance often demands of independent institutions and individuals whose reluctance to participate may preclude the kinds of comparisons and the volume of cases needed for strong evaluations.

In addition, several more general challenges may complicate evaluations of clinical telemedicine. One is the restructuring of the nation's health care delivery system, which has brought with it shifts in institutional missions and priorities related to patient care, education, and research. A second is the growth of investor-owned enterprises that are not much inclined to allocate resources for purposes such as clinical research that do not add to corporate profits. At the state and federal level, policymakers are cutting budgets and may be reluctant to shift even modest resources from the core activities of grant programs to support evaluations of their actual consequences.

Fortunately, a number of government and private organizations