Demographically adjusted CERAD wordlist test norms in a Norwegian sample from 40 to 80 years

Abstract

Background/Objective: In recent years, several slightly younger cohorts have been established in order to study the preclinical and prodromal phases of dementia. The Consortium to Establish a Registry for Alzheimer’s Disease (CERAD) wordlist memory test (WLT) is widely used in dementia research. However, culturally adapted and demographically adjusted test norms for younger ages are lacking. Method: This paper investigates effects of age, gender and years of education on test performance and offers demographically adjusted norms for the CERAD WLT using a regression-based norming procedure for the age span 40–80years based on healthy controls (n¼227) from the Norwegian “Dementia Disease Initiation” (DDI) (n¼168) and “Trønderbrain” (n¼59) cohorts. In order to evaluate normative performance, we apply the norms to an independent sample of persons diagnosed with mild cognitive impairment (MCI = 168) and perform multiple regression analyses to evaluate adjustment of pertinent demographics. Results: CERAD WLT norms adjusted for effects of age, gender and educational level are proposed. The norms successfully adjusted for effects of age, gender and education in an independent sample of Norwegians with MCI. Conclusion: Demographically adjusted norms for the CERAD WLT for ages 40–80years based on a Norwegian sample are proposed. To our knowledge, this is the first normative study of this test to offer demographically adjusted norms for this age span.