ABSTRACT
To answer these questions, the perspectives and opinions of scientists and physicians knowledgeable about the development and use of CTP technology were elicited through in-depth interviews, conducted by telephone and a number of site visits, and augmented with e-mail exchanges. Over the course of the collection of benefit data, 66 individuals provided information that complemented literature reviews and other data collection methods. Thirteen experts provided information that specified the final counterfactual CTP.14
