Behavioural measures in frontotemporal lobar dementia and other dementias: the utility of the frontal behavioural inventory and the neuropsychiatric inventory in a national cohort study.

BACKGROUND: Distinguishing between patients with frontotemporal lobar dementia (FTLD) and other dementing illnesses remains a difficult task for many clinicians. In this study, we aimed to provide further evidence for the construct validity of the frontal behavioural inventory (FBI) and assess its utility in differentiating FTLD patients from other groups using data from the Canadian Collaborative Cohort of Related Dementias (ACCORD) study. METHOD: Baseline scores on the FBI and neuropsychiatric inventory (NPI) were compared among several clinical groups (n = 177). RESULTS: The FBI discriminated a higher percentage of FTLD patients (>75% correct classification) from Alzheimer's disease and other groups compared to the NPI (54.2%). CONCLUSION: This study provides good evidence for convergent validity between the FBI and NPI (r = 0.72), indicating that both measures capture similar psychopathology in this nationwide cohort.