Development of the German social attitude barriers and facilitators to participation-scales: an analysis according to the Rasch model

Abstract

Abstract Background Social attitudes experienced by people with disabilities can strongly impact upon their health and quality of life. The extent to which social attitude measurement transcends specific cultures is unknown. Thus, the aim of the study was to develop German item banks to assess social attitude barriers and facilitators to participation and compare the construct definition with that developed in the United States. Methods The American version of the two item banks assessing social attitudes that act as barriers and facilitators in persons with disabilities was translated into German and culturally adapted. The sample consisted of 410 in- and outpatients treated for spinal diseases at a German University Hospital. The psychometric properties of the resulting 53 items-item pool were evaluated using Rasch analysis. A special focus was placed on the investigation of unidimensionality, local independence, differential item functioning (DIF) and targeting. To evaluate convergent and divergent validity correlations with perceived social support, depression and pain interference were calculated. Results Unlike the American version, both the barriers and facilitators item banks had to be divided into two subscales assessing attitudes that individuals with disabilities experience as being directed towards them (individual perception) or attitudes that respondents experience as being directed towards people with disabilities as a social group (societal perception). Four unidimensional scales were constructed. Fit to the Rasch model required item deletion and forming testlets to account for extensive local dependence. There was no evidence of DIF with regard to gender or age. Targeting of the subscales was moderate to good. Conclusions Results support a distinction between social attitudes at the individual and societal level, allowing a more specific assessment than is possible when this distinction is ignored.