ABSTRACT
This chapter reviews the issues that need to be addressed to develop a robust user interface that will be suitable for data collection with the wide variety of patients enrolled in clinical trials. It presents these issues from the point of view of a system designer, but the principles outlines are just as important for those who select a system from a vendor or specify the details for a particular study protocol. The chapter describes apply equally when developing an ePRO system from scratch or when transferring an existing paper instrument to electronic mode. All information required by the patient should be visible on the screen, and that scroll bars should be avoided. In 1993, the first Personal Digital Assistants (PDAs), hand-held computers with pen interfaces appeared and a number of research groups began to use them to collect data directly from patients, either to take home to use as symptom diaries, or for collecting questionnaire data in the clinic.
