A Normative Study of Lexical Verbal Fluency in an Educationally-Diverse Elderly Population

Abstract

Objective Lexical fluency tests are frequently used to assess language and executive function in clinical practice. We investigated the; influences of age, gender, and education on lexical verbal fluency in an educationally-diverse, elderly Korean population and provided its' normative information. Methods We administered the lexical verbal fluency test (LVFT) to 1676 community-dwelling, cognitively normal subjects aged 60 years or over. Results In a stepwise linear regression analysis, education (B=0.40, SE=0.02, standardized B=0.506) and age (B=-0.10, SE=0.01, standardized B=-0.15) had significant effects on LVFT scores (p<0.001), but gender did not (B=0.40, SE=0.02, standardized B=0.506, p>0.05). Education explained 28.5% of the total variance in LVFT scores, which was much larger than the variance explained by age (5.42%). Accordingly, we presented normative data of the LVFT stratified by age (60-69, 70-74,75-79, and >= 80 years) and education (0-3, 4-6, 7-9, 10-12, and >= 13 years). Conclusion The LVFT norms should provide clinically useful data for evaluating elderly people and help improve the interpretation of verbal fluency tasks and allow for greater diagnostic accuracy.