“…Validity and reliability in quality of life research has been discussed (Macduff, 2000;Moons et al, 2006). Good validity and international relevance of this study is provided by using the SRI questionnaire, that has shown very good psychometric qualities and has been professionally adapted and translated into several languages (Duiverman, Wempe, Bladder, Kerstjens, & Wijkstra, 2008;Ghosh, Rzehak, Elliott, Windisch, 2012;Huttmann et al, 2015, p. 280;L opez-Campos et al, 2008;MacIntyre et al, 2016;Markussen et al, 2015;Oga et al, 2017;Ribeiro, Ferreira, Conde, Oliveira, & Windisch, 2017;Struik et al, 2013;Windisch, 2008;Windisch et al, 2003). Reliability and rigour are provided through high-quality clinical data from the LTMV registry.…”