Prevalence and correlates of dementia and mild cognitive impairment classified with different versions of the modified Telephone Interview for Cognitive Status (TICS-m).

Abstract

The modified Telephone Interview for Cognitive Status (TICS-m) is an efficient and cost-effective screening instrument of dementia, but there is less support for its utility in the detection of mild cognitive impairment (MCI). We undertook a comprehensive evaluation of the utility of different TICS-m versions with or without an education-adjusted scoring method to classify dementia and MCI in a large population-based sample. Cross-sectional assessment of cognition (TICS-m), depressive symptoms (CES-D), and apolipoprotein E (APOE) ε4 status was performed on 1772 older adults (aged 71-78 y, education 5-16 y, 50% female) from the population-based older Finnish Twin Cohort. TICS-m classification methods with and without education adjustment were used to classify individuals with normal cognition, MCI, or dementia. The prevalence of dementia and MCI varied between education-adjusted (dementia = 3.7%, MCI = 9.3%) and unadjusted classifications (dementia = 8.5%-11%, MCI = 22.3%-41.3%). APOE ε4 status was associated with dementia irrespective of education adjustment, but with MCI only when education adjustment was used. Regardless of the version, poorer continuous TICS-m scores were associated with higher age, lower education, more depressive symptoms, male sex, and being an APOE ε4 carrier. We showed that demographic factors, APOE ε4 status, and depressive symptoms were similarly related to continuous TICS-m scores and dementia classifications with different versions. However, education-adjusted classification resulted in a lower prevalence of dementia and MCI and in a higher proportion of APOE ε4 allele carriers among those identified as having MCI. Our results support the use of education-adjusted classification especially in the context of MCI.