@article{MaritzTennantFellinghaueretal.2019, author = {Maritz, R. and Tennant, A. and Fellinghauer, C. and Stucki, G. and Prodinger, Birgit}, title = {The Extended Barthel Index (EBI) can Be Reported as a Unidimensional Interval-Scaled Metric - A Psychometric Study}, series = {Physikalische Medizin, Rehabilitationsmedizin, Kurortmedizin}, volume = {29}, journal = {Physikalische Medizin, Rehabilitationsmedizin, Kurortmedizin}, number = {04}, pages = {224 -- 232}, year = {2019}, abstract = {Background: The Extended Barthel Index (EBI), consisting of the original Barthel Index plus 6 cognitive items, provides a tool to monitor patients' outcomes in rehabilitation. Whether the EBI provides a unidimensional metric, thus can be reported as a valid sum-score, remains to be examined. Objective: To examine whether the EBI can be reported as unidimensional interval-scaled metric for neurological and musculoskeletal rehabilitation. Methods: Rasch analysis of a calibration sample of 800 cases from neurological or musculoskeletal rehabilitation in 2016 in Switzerland. Results: In the baseline analysis no fit to the Rasch Model was achieved. When accommodating local dependencies with a testlet approach satisfactory fit to the Rasch Model was achieved, and an interval scale transformation table was created. Conclusion: The results support the reporting of adapted EBI total scores for both rehabilitation groups by applying the interval scaled transformation table presented in this study.}, language = {en} }