OBJECTIVES: To analyze subjects’ interpretation of concepts specific to Chronic Obstructive Pulmonary Disorder (COPD) during pilot testing of translated Patient Reported Outcomes (PRO) questionnaires. As observed during pilot testing of translated COPD questionnaires, COPD-specific concepts were observed to cause more comprehension difficulties across languages, compared to observed questionnaires for other diseases.  Solutions for these comprehension difficulties in COPD questionnaires will be explored. METHODS: Pilot testing data for the concepts rescue medication, wheezing, the acronym COPD, and chest tightness within PROs were analyzed. Testing was conducted with five subjects per language for three questionnaires. Subjects were asked to paraphrase the COPD questionnaires in their entirety. Suggestions for improved comprehension of COPD concepts were explored, resulting from pilot testing data. RESULTS: Rescue medication caused difficulty within half of the languages analyzed. To improve comprehension, subjects suggested supplementing rescue medication with “(fast acting and quick relief medication)” for improved comprehension. Wheezing was a problematic concept for Spanish, South African Bantu and Indian languages. The subjects’ proposed solution for these languages was supplementation of wheezing with “(heavy breathing accompanied by a whistle sound).” Use of the COPD acronym proved problematic for 27% of languages. Even in languages where an equivalent acronym exists, comprehension issues persisted. Subjects suggested expansion of the acronym to “Chronic Obstructive Pulmonary Disorder.” Chest tightnesscaused minimal comprehension issues which were not significant enough to merit usable suggestions. CONCLUSIONS: Following translation of COPD questionnaires, pilot testing in the target language is essential, as concepts specific to COPD are found to be difficult. Because medical and technical concepts cannot be substituted, supplementation with brief definitions for increased comprehension and expansion of acronyms is recommended when developing source PRO questionnaires specific to COPD.