Item response theory for the color-picture version of Boston naming test in a Chinese sample with neurodegenerative diseases

Background Although Boston Naming Test has been thoroughly validated at a global level, there is limited assessment of item-level properties using modern psychometric methods. Objective This study aimed to investigate the construct validity and item-level properties of the color-picture version of Boston Naming Test (CP-BNT) in a Chinese cohort with neurodegenerative diseases. Methods This retrospective study included 424 participants, consisting of 118 normal controls, 152 with Alzheimer's disease, 101 with primary progressive aphasia, and 53 with other neurodegenerative diseases. All participants underwent a comprehensive neuropsychological assessment that included the CP-BNT. Factor analysis and item response theory were conducted. Results The CP-BNT exhibits a multidimensional structure with three factors: Factor 1, consisting of nine items with moderate difficulty levels, demonstrated peak measurement function for mild anomia (the highest information value = 33.7, ability estimated value = -0.8, reliability = 0.97); Factor 2, comprising eleven items with lower difficulty levels, performed well in cases of mild to moderate anomia (the highest information value = 34.1, ability estimated value = -1.2, reliability = 0.97); and Factor 3, including ten items with higher difficulty levels, provided the most measurement information for normal naming (the highest information value = 9.9, ability estimated value = 0, reliability = 0.90). All items, except item igloo, showed good discrimination (discrimination parameter ranged from 5.46 to 1.15). Most items had a different difficulty position versus the original version, thereby generating a novel item sequence with an ascending difficulty hierarchy for Chinese samples. Conclusions These findings support that the CP-BNT has good validity, reliability, and cultural appropriateness in the Chinese context, improving its utility in clinical assessments and interventions.