From project to project and application to application, specific questions and evaluation criteria will vary because clinical telemedicine varies so much in the patient problems addressed, the specific outcomes sought, the diagnostic and therapeutic strategies employed, and information and telecommunications infrastructure required. For example, the dimensions of access relevant for teleradiology can be expected to differ from those considered for telepsychiatry. The health outcomes and cost data relevant for chronically ill homebound patients will not match those relevant for emergency medicine, although some measures of patient and clinician acceptance may be virtually the same. Some evaluations may appropriately stop short of directly assessing health outcomes and consider only the adequacy of the information (e.g., image resolution for mammograms) available from the application compared to the alternative.
Insofar as possible, evaluators should begin with some sense of what constitutes favorable or unfavorable (or acceptable or unacceptable) outcomes for a telemedicine application in a particular context. Again, the specification may vary from evaluation to evaluation. Superior outcomes at equivalent cost may be the goal for some evaluations, whereas others may look for reduced cost with equivalent quality. For evaluations that are beyond the "test of concept" phase, a central question will often be: Do the quality, access, cost, and other results suggest whether and how the telemedicine program can be sustained beyond the evaluation stage?
Given the large number of possible quality, access, cost, and acceptability measures for different clinical applications of telemedicine and the difficulty of stipulating many of them in the abstract, the committee did not present application-specific measures and criteria. Instead, they identified several sets of basic questions to guide the selection of evaluation criteria or measures for particular telemedicine evaluation projects (see Box 8.2).
Although the questions about quality, access, cost, and patient and clinician perceptions are presented sequentially, their interactions and interrelationships also warrant evaluation. This is most obvious in cost-effectiveness analyses that relate the costs of an application to its benefits. It is also plausible that the timeliness of care—an element of access as defined here—may have important