Psychometric Properties of the Toileting Behaviour Evaluation (TBE) Using Rasch Analysis

This study assessed the psychometric properties of the Toileting Behaviour Evaluation (TBE), a tool designed to address the limitations of traditional assessments like the Functional Independence Measure and Barthel Index in capturing the complexities of toileting activities among wheelchair users. Conducted with 250 wheelchair users from six rehabilitation hospitals in Japan, the study used Rasch analysis to evaluate the TBE's internal validity, reliability, and unidimensionality across 22 toileting components. The analysis confirmed the TBE's fit to the Rasch model, with a raw variance explained by measures of 70.1%, a person separation index of 3.82 (reliability coefficient=0.94), and an item separation index of 5.94 (reliability coefficient=0.97), supporting its use as a valid and reliable tool. Additionally, a conversion table was developed to transform ordinal scores into interval measures, enhancing clinical applicability. The study suggests that the TBE is a psychometrically sound instrument for assessing toileting behavior in wheelchair users. However, further research is recommended to explore its effectiveness in clinical interventions and its applicability across different populations and diagnoses.