Psychometric properties of the stroke specific quality of life scale for the assessment of participation in stroke survivors using the rasch model: a preliminary study

[Purpose] The aim of the present study was to analyze the psychometric properties of the Stroke Specific Quality of Life (SS-QOL) scale for the assessment of social participation following a stroke. [Methods] A preliminary analysis was performed of the SS-QOL items that address the participation category. For this, the scoring patterns of the answers of individuals and internal consistence were determined using the Rasch model. Reliability was assessed by intraclass correlation coefficients (ICC). [Results] The reliability coefficients analyzed by the Rasch model were 0.91 for the items and 0.87 for the patients. The separation index was 3.19 for the items and 2.58 for the patients. The findings indicate that the items separated the patients into three levels of participation: low, medium, and high. Among the 26 items addressing participation, three did not fit the model. All items showed adequate reliability (ICC >= 0.60). [Conclusion] The Rasch analysis detected three items with erratic behavior; however, the erratic patterns of these items may be explained by individual peculiarities among the patients. These items should be monitored to determine if the problems found in the present study persist. If so, the items should also be revised or possibly even eliminated.