OBJECTIVES: The FDA currently requires patient interviews in the process of developing a new PRO measure. In the past, many questionnaires were developed based solely on clinician expertise and patient involvement in the creation of items was non-existent. In order to ensure existing questionnaires are accepted by the FDA, it is necessary to confirm the content validity of questionnaires that were not based on patient interviews. The 25 and 18 item RMDQ is a measure of pain and function widely used in low back pain (LBP) trials that was based solely on clinician involvement. METHODS: Two US focus groups (n=15) and one UK focus group (n=7) were asked to complete the problem elicitation technique (PET) alongside the RMDQ to determine the relevance of items. The PET measures the importance of concepts based on a series of questions rating the importance of each item on a five-point likert response continuum. To ensure the RMDQ was not missing any relevant items participants were asked several open-ended questions. RESULTS: Participants confirmed the content validity of the RMDQ by identifying four areas of importance: pain/discomfort, activities of daily living, sleep problems and emotional impact. Based on the PET, all RMDQ items were rated as moderately to extremely important (item score range of 3.57 – 4.36 on a one – five scale). Items rated least important were the same items removed in the 18 item version. In the open ended questions, sleep disturbances was consistently mentioned as a primary area of concern. CONCLUSIONS: The PET augmented by open-ended questions is a valid method for confirming the content validity of questionnaires that did not include patient involvement in their development. These findings support the continued use of the RMDQ in LBP trials; however, consideration should be given to including additional sleep questions or measuring this concept separately.