Clinimetrics of the Shortened Frontal Assessment Battery (FAB15) in Neurodegenerative Disorders

Abstract

This study aimed to provide a clinimetric evaluation of the shortened Frontal Assessment Battery (FAB15) in a large cohort of patients with neurodegenerative disorders. FAB15 scores were retrospectively retrieved from 379 patients with neurocognitive disorders and 260 healthy controls (HCs). The clinical cohort included patients with mild cognitive impairment (MCI) and dementia due to Alzheimer’s disease (AD; n = 147), AD with mixed etiology ( n = 26), frontotemporal lobar degeneration (FTLD; n = 52), and Lewy body disease (LBD; n = 32). First, we tested the discriminatory power of FAB15 across etiologies and disease severity. Then, optimal cutoffs were derived, and available normative thresholds were tested for their diagnostic performance. Within the clinical sample, factorial structure, internal consistency, construct validity, and ecological validity were also examined. After demographic adjustment, a FAB15 cutoff around 11 optimally discriminated HCs from patients with neurodegenerative disease. Importantly, discrimination was stronger for dementia than MCI and remained consistent across etiologies, with the best performance observed in LBD. Overall, normative cutoffs were highly specific but poorly sensitive, with their screening utility being largely prevalence-dependent. Psychometrically, the FAB15 showed a unidimensional factor structure, strong convergence with executive measures, and weaker associations with episodic memory tasks, as well as functional autonomies. The FAB15 is a clinimetrically and psychometrically sound screener for detecting executive dysfunction in neurodegenerative disorders.