Repeatable battery for assessment of neuropsychological status in early Parkinson's disease.

Adequate reliability and valid factor structure are prerequisites for appropriate use of a measure in a population. Although the Repeatable Battery for Assessment of Neuropsychological Status (RBANS) has been used to examine cognition in Parkinson's disease (PD), its reliability and factor structure have not been examined in this population. This study examined the reliability and factor structure of the RBANS in participants with de novo PD recruited for two NIH Exploratory Trials in Parkinson's Disease (NET-PD), using Cronbach's alpha and factor analysis. Confirmatory factor analysis (CFA) was implemented on the factor structure proposed in the RBANS manual, and exploratory factor analysis (EFA) was conducted to identify a valid factor structure given the proposed one was not supported. The RBANS exhibited poor reliability in participants with NET-PD. Cronbach's alpha ranged from 0.03 to 0.74 for the five domains and the full scale. CFA results indicated that the proposed factor structure in the RBANS manual was not supported in this sample. EFA identified a two-factor structure for six of the 12 RBANS items. Six items were eliminated due to low correlation with other items or severe ceiling effects. This new factor structure was validated by another CFA. The two domains have fair reliability. Cronbach's alpha ranged from 0.65 to 0.74 for the two factors in the two datasets. These results suggest that the current RBANS domain and total scores may not provide valid measurement of the neuropsychological status for patients with early PD. Copyright 2009 Movement Disorder Society.