Background:The Systemic Sclerosis Quality of Life Questionnaire (SScQoL) has been validated in six European languages.1Previous adaptation into German revealed issues with the dichotomous response structure in 10 items necessitating a review of the tool and further psychometric testing with patients in German speaking countries.Objectives:The aim of this study was to assess the German version of the SScQoL, extend the response structure and test its construct validity using Mokken scale analysis.Methods:This was a mixed methods study involving cognitive debriefing and survey methods. The expert committee extended the response structure of the 10 items from dichotomous to polytomous (4-point) responses: ‘always’, ‘usually’, ‘sometimes’ and ‘never’. In cognitive debriefing, a small convenience sample of patients with SSc completed the new version while ‘thinking aloud’ and commented on relevance of the items and the response structure.Results:In cognitive debriefing, six patients with SSc completed the new German SScQoL and reported problems with the remaining dichotomous items. These were subsequently converted into polytomous 4-point response structure by the expert committee.Conclusion:The German SScQoL has been revised into polytomous item structure and shown to be a valid and reliable measure of health-related quality of life in SSc. Further cross-cultural validity tests are required to assess its measurement equivalence with other SScQoL versions and thus enable multinational comparisons.References:[1]Ndosi M, Alcacer-Pitarch B, Allanore Y et al. Common measure of quality of life for people with systemic sclerosis across seven European countries: a cross-sectional study. Ann Rheum Dis, 2018; 77: 1032-1038Table 1.Mokken scale analysis of the revised German SScQoLSubscale (items)Scalability (H)Standard errorFunction (6)0.6640.048Emotional (13)0.6520.060Sleep (2)0.7980.061Social (6)0.6920.053Pain (2)0.9600.029Global scale (29)0.6230.062Table legend: scalabilityH≥ 0.50 = strong, 0.49 to 0.40 = moderate, 0.39 to 0.30 = weak, while values of < 0.30 are not considered as unidimensional.Disclosure of Interests:Agnes Kocher Grant/research support from: Sandoz to support the development of an eLearning module for patients with rheumatic diseases., Mwidimi Ndosi Grant/research support from: Bristol Myers Squibb, Consultant of: Janssen, Pfizer, Kirsten Hoeper Consultant of: AbbVie, Celgene,, Speakers bureau: Abbvie, Chugai, Novartis, Lilly, Celgene, Sandoz Hexal, Michael Simon: None declared, Dunja Nicca: None declared
