Validation of the Malayalam Version of Alzheimer’s Disease Assessment Scale – Cognitive Subscale (ADAS-Cog) for the South Indian Population

Background: With the rise in dementia in India, there is a need to develop culturally sensitive diagnostic tools. The Alzheimer’s Disease Assessment Scale–Cognitive Subscale (ADAS-Cog) is a diagnostic, subjective, and objective assessment tool. This study aims to culturally validate the tool in Malayalam for the South Indian population. Methods: The study was conducted in the Kozhikode and Malappuram districts in Kerala, India. For adaptation, the tool was translated to Malayalam, and an expert panel of key stakeholders were interviewed to make any culturally appropriate changes to the tool. For validation of the tool, 49 cases and 50 controls were recruited, and the ADAS-Cog was administered to them. Internal consistency, concurrent validity, inter-rater reliability, and discriminant validity were assessed using Cronbach’s alpha, Spearman’s correlation, intraclass correlation coefficient, and by plotting the receiver operating characteristic curve and computing the area under the curve, respectively. Sensitivity and specificity scores were also obtained. Results: The ADAS-Cog Malayalam version shows good internal consistency ( α = 0.92), interrater reliability and concurrent validity (with Community Screening Instrument for Dementia - Caregiver version: r = −0.653 and Clinical Dementia Rating: r = 0.618). A cutoff score of 13.5 has a specificity of 100% and sensitivity of 98% for the diagnosis of dementia. Conclusion: The ADAS-Cog Malayalam tool was developed after its cultural and linguistic adaptation involving various relevant stakeholders in the field of dementia working in the Malayalam-speaking community. The validated tool can now be of use in the clinical settings with the urban Malayalam-speaking population in South India.