Demographically-adjusted norms for selected tests of verbal fluency: Results from the Neuropsychological Norms for the US-Mexico Border Region in Spanish (NP-NUMBRS) project

Abstract

Objective

Verbal fluency tests are sensitive to various disorders affecting the central nervous system and are commonly included in neuropsychological evaluations. We aimed to develop normative data for two verbal fluency tests in a sample of native Spanish-speakers living in the US-Mexico border region.

Method

Participants included 254 adults from the Neuropsychological Norms for the US-Mexico Border Region in Spanish (NP-NUMBRS) Project (Age: range = 19–60; Education: range = 0–20, 59% female). Participants completed two verbal fluency tests (i.e., letter [PMR] and semantic/category fluency [Animal Naming]) as part of a larger neuropsychological test battery. We examined linear and nonlinear effects of demographic factors (age, education, and gender) on verbal fluency raw scores, and developed T-scores using fractional polynomial equations controlling for demographics. We also calculated the rates of “impairment” (T-scores < 40) that would be obtained by applying the newly developed norms and available norms for non-Hispanic English-speakers on comparable tests.

Results

There were positive small effects of age and medium effects of education on verbal fluency raw scores. The normalized distribution of T-scores with the new norms showed expected psychometric properties. However, rates of impairment for both letter and semantic fluency were significantly higher when applying non-Hispanic White norms, and significantly lower when applying non-Hispanic Black norms.

Conclusions

We provide norms for Spanish-speakers living along the US-Mexico border region for two verbal fluency tests that are co-normed with a more extensive neuropsychological battery. These regional norms will improve interpretation of verbal fluency test performance in Spanish-speakers living in the US-Mexico borderland.

KEYWORDS:

• Hispanic/Latino
• language
• neuropsychological assessment
• cognitive testing

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was supported by grants from the National Institutes of Health (P30MH62512, R01MH57266, K23MH105297, P30AG059299, T32MH019934) and the UCSD Hispanic Center of Excellence (funded by the Health Resources & Services Administration grant D34HP31027).