Normative Data for the Alternating and Orthographic Constraint Semantic Fluency Tests in the Adult French-Quebec Population and Validation Study in Mild Cognitive Impairment and Alzheimer's Disease.

Abstract

Verbal fluency tests, known to elicit executive functions (EFs), have proven useful in distinguishing healthy individuals from those with cognitive impairment. The present study addresses two new tests of verbal fluency that elicit EFs, namely, extradimensional alternating fluency (EAF) and extradimensional orthographic constraint semantic fluency (EOCSF). The aim of Study 1 was to provide normative data in the adult and elderly population of French Québec for the two fluency tests. The aim of Study 2 was to determine their psychometric value. The normative sample consisted of 338 healthy controls (HCs) aged 50-89years. Multiple linear regressions were used to generate equations for calculating Z-scores. Convergent validity was established by administering the two verbal fluency tests and the Letter-Number Sequence (LNS) subtest of the WAIS-III. To assess predictive validity, the performance of 19 HCs was compared with that of 19 participants with mild cognitive impairment (MCI) and 19 participants with Alzheimer's disease (AD). To determine test-retest reliability, the test was administered twice, 3months apart, to a subsample of 20 HCs. Age and educational level were significantly related to performance in the EAF and the EOCSF. The two tests correlated significantly and positively with the LNS. The EAF and the EOCSF distinguished the performance of HCs from that of participants with MCI or AD. A test-retest analysis showed that scores on the two tests were stable over time. The norms and psychometric data for the EAF and the EOCSF will help clinicians and researchers better identify executive impairments associated with pathological conditions.