The survey was developed by the PROMS ECT members working with members of the Working Group 1 (Research, Development and Validation), and supported by an external research team from Qualitative Research Unit – Azienda USL – IRCCS (Reggio Emilia), Italy. Members of the ECT developed the list of ‘functional domains’ and their descriptions, and advised on the survey design and questions.  The survey was piloted in all languages to around 100 people with MS.