OBJECTIVES Usability testing of electronic Patient-Reported Outcomes (ePRO) instruments is typically conducted during instrument development, in the language/country of origin.  It has been suggested that usability testing also be performed during the translation process.  It is unclear whether this additional step is necessary.  In this study, usability testing was conducted as part of the linguistic validation process in Simplified Chinese (China), German (Germany), French (France), Russian (Russia), and Spanish (Universal, tested in Chile, Spain, and US) for the Exacerbations of Chronic obstructive pulmonary disease Tool (EXACT), an e-PRO developed and tested in English (US). METHODS The translation process followed ISPOR guidelines (Wild et al., 2005).  Cognitive interviews were conducted with 2-3 native-speaking COPD respondents per language/country combination in 2008.  Subjects completed the EXACT in paper-pen screenshot format and were interviewed for translation validation.  Subsequently they were instructed to use a PDA (Tungsten E2; CRF, Inc.) to complete the first 5 EXACT items and were interviewed regarding device usability. Interviewers rated subjects’ ability to use the device. RESULTS Subjects (N=20) were 45-84 years, 60% male, and 60% with secondary education or less.  Most (n=18) had not used a PDA previously; all (n=20) reported it was easy to use, the screens were easy to read, and that they could sign on and move through the questions with no difficulty. Subjects from the Spanish-speaking countries had the lowest reported difficulty turning the device on, with higher levels of difficulty observed by the interviewers in China, who reported “somewhat” for two of the three respondents. Interviewers observed that the majority (n=15) could “easily” or “very easily” use the device. CONCLUSIONS Given the consistent ease-of-use findings in these diverse, device naïve subjects across 7 countries and the emphasis on subject training in clinical trials, it was determined that usability testing with future translations was unnecessary.