“…In research, QoL is mostly used as an outcome measure for interventions or quality of care. In a narrative literature review (Nieuwenhuijse, Willems, van Goudoever, Echteld, & Olsman, 2017) we found that questionnaires, for example the QoL-PMD (Petry, Maes, & Vlaskamp, 2009a, 2009b and San Martin scale (Verdugo, Gomez, Arias, Navas, & Schalock, 2014), and behavioural observations (Petry & Maes, 2006;Vos, De Cock, Petry, Van Den Noortgate, & Maes, 2013) were frequently used as methods to assess QoL. Parents, family, primary caregivers and researchers were the assessors of QoL.…”