Development and validation of the Neuro-Score: a specific scale to detect and monitor cognitive impairment in kidney or liver transplant recipients

Abstract

We created and validated the Neuro-Score, a specific scale to detect and monitor cognitive impairment, including mild stages, in kidney or liver transplant recipients. A qualitative study was conducted to define a preliminary set of 62 items. Item reduction was performed using exploratory factor analysis. Confirmatory factor analysis assessed the adequacy of the factorial solution. The total scores of the Neuro-Score and mini-mental state examination were compared. Responsiveness to change was evaluated from visit 1 (baseline) to 2A (18 months later) and temporal stability from visit 2A to 2B (1-2 weeks later). Factor analysis showed 11 factors with an eigenvalue of >1. Confirmatory factor analysis yielded a logical solution with 1 factor and 11 items that explained 27.9% of the variance. The final model showed satisfactory internal consistency (Cronbach alpha- 0.82). A weak negative correlation was found between Neuro-Score and mini-mental state examination total scores (Pearson r--0.12; P-.0095). The Neuro-Score responsiveness to change was demonstrated (P-.022). No significant differences in the total score were observed between visits 2A and 2B, supporting the Neuro-Score temporal stability. The Neuro-Score scale is a simple, reliable, self-administered, easy-to-interpret, and consistent 11-item scale to detect and monitor cognitive impairment in kidney and liver transplant recipients.