Literacy Independent Cognitive Assessment: Assessing Mild Cognitive Impairment in Older Adults with Low Literacy Skills

Abstract

Objective Comprehensive neuropsychological tests are important in the diagnosis and follow-up of patients with MCI; however, most were developed without consideration of illiteracy. We developed the Literacy Independent Cognitive Assessment (LICA) as a comprehensive neuropsychological assessment battery applicable to older adults who are either literate or illiterate. This study aimed to assess the reliability and validity of the LICA for diagnosis of MCI. Methods Normal controls (n=634) and patients with MCI (n=128) were recruited from 13 centers were included in this study. Participants were divided into illiterate or literate groups, based on their performance on a brief reading and writing test. The LICA, Korean Mini-Mental State Examination (K-MMSE), and Seoul Neuropsychological Screening Battery (SNSB) were administered. Results Total LICA scores distinguished MCI patients from controls (p<0.001). They were closely and positively correlated to the K-MMSE scores (r=0.632, p<0.001) but negatively correlated to clinical dementia rating (CDR) (r=-0.358, p<0.001) and CDR sum of boxes (r=-0.339, p<0.001). Area under the receiver operating characteristic curve for patients with MCI by total LICA score was 0.827 (0.783-0.870), superior to that presented by the K-M.MSE. For the classification of MCI subtypes, inter-method reliability of LICA with the SNSB was good (kappa 0.773; 0.679-0.867, p<0.001). Conclusion The results of this study show that the LICA may be reliably used to distinguish MCI patients from cognitively intact adults, to identify MCI subtypes and monitor progression toward dementia, regardless of illiteracy