Epidemiology of Motoric Cognitive Risk Syndrome in the Kerala Einstein Study: Protocol for a Prospective Cohort Study.

BACKGROUND: The southern India state of Kerala has among the highest proportion of older adults in its population in the country. An increase in chronic age-related diseases such as dementia is expected in the older Kerala population. Identifying older individuals early in the course of cognitive decline offers the best hope of introducing preventive measures early and planning management. However, the epidemiology and pathogenesis of predementia syndromes at the early stages of cognitive decline in older adults are not well established in India. OBJECTIVE: The Kerala Einstein Study (KES) is a community-based cohort study that was established in 2008 and is based in the Kozhikode district in Kerala state. KES aims to establish risk factors and brain substrates of motoric cognitive risk syndrome (MCR), a predementia syndrome characterized by the presence of slow gait and subjective cognitive concerns in individuals without dementia or disability. This protocol describes the study design and procedures for this KES project. METHODS: KES is proposing to enroll a sample of 1000 adults ≥60 years old from urban and rural areas in the Kozhikode district of Kerala state: 200 recruited in the previous phase of KES and 800 new participants to be recruited in this project. MCR is the cognitive phenotype of primary interest. The associations between previously established risk factors for dementia as well as novel risk factors (apathy and traumatic brain injury) and MCR will be examined in KES. Risk factor profiles for MCR will be compared between urban and rural residents as well as with individuals who meet the criteria for mild cognitive impairment (MCI). Cognitive and physical function, medical history and medications, sociodemographic characteristics, lifestyle patterns, and activities of daily living will be evaluated. Participants will also undergo magnetic resonance imaging and electrocardiogram investigations. Longitudinal follow-up is planned in a subset of participants as a prelude to future longitudinal studies. RESULTS: KES (2R01AG039330-07) was funded by the US National Institutes of Health in September 2019 and received approval from the Indian Medical Council of Research to start the study in June 2021. We had recruited 433 new participants from urban and rural sites in Kozhikode as of May 2023: 41.1% (178/433) women, 67.7% (293/433) rural residents, and 13.4% (58/433) MCR cases. Enrollment is actively ongoing at all the KES recruitment sites. CONCLUSIONS: KES will provide new insights into risk factors and brain substrates associated with MCR in India and will help guide future development of regionally specific preventive interventions for dementia. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): DERR1-10.2196/49933.

Cultural adaptation of Alzheimer's disease assessment scale-cognitive subscale for use in India and validation of the Tamil version for South Indian population.

OBJECTIVE: Currently no standardized tools are available in the Indian languages to assess changes in cognition. Our objectives are to culturally adapt the Alzheimer's disease Assessment Scale-Cognitive Subscale (ADAS-Cog) for use in India and to validate the Tamil version in an urban Tamil-speaking older adult population. METHODS: Two panels of key stakeholders and a series of qualitative interviews informed the cultural and linguistic adaptation of the ADAS-Cog-Tamil. Issues related to levels of literacy were considered during the adaptation. Validation of the ADAS-Cog-Tamil was completed with 107 participants - 54 cases with a confirmed diagnosis of mild-moderate dementia, and 53 age, gender and education matched controls. Concurrent validity was examined with the Vellore Screening Instrument for Dementia (VSID) in Tamil. Internal consistency using Cronbach's alpha, sensitivity and specificity data using the Area under the Receiver Operating Characteristics (AUROC) curve values were computed. Inter-rater reliability was established in a subsample. RESULTS: The ADAS-Cog-Tamil shows good internal consistency (α = 0.91), inter-rater reliability and concurrent validity (with VSID-Patient version: r = -0.84 and with VSID-Caregiver version: r = -0.79). A cut-off score of 13, has a specificity of 89% and sensitivity of 90% for the diagnosis of dementia. CONCLUSION: ADAS-Cog-Tamil, derived from a rigorous, replicable linguistic and cultural adaptation process involving service users and experts, shows good psychometric properties despite the limitations of the study. It shows potential for use in clinical settings with urban Tamil speaking populations. The English version of the tool derived from the cultural adaptation process could be used for further linguistic adaptation across South Asia.

Picture-based memory impairment screen for dementia.

OBJECTIVES: To develop and validate a picture-based memory impairment screen (PMIS) for the detection of dementia. DESIGN: Cross-sectional. SETTING: Outpatient clinics, Baby Memorial Hospital, Kozhikode city in the southern Indian state of Kerala. PARTICIPANTS: Three hundred four community-residing adults aged 55 to 94 with a mean education level of 8 years; 65 were diagnosed with dementia. MEASUREMENTS: PMIS: a culture-fair picture-based cognitive screen designed to be administered by nonspecialists. Diagnostic accuracy estimates (sensitivity, specificity, positive and negative predictive power) of PMIS cut-scores in detecting dementia (range 0-8). RESULTS: PMIS scores were worse in participants with dementia (1.5) than in controls (7.7, P < .001). At the optimal cut-score of 5, PMIS had a sensitivity of 95.4% (95% confidence interval (CI) = 90.3-100.0%) and a specificity of 99.2% (95% CI = 98.0-100.0%) for detecting dementia. In the 167 participants with <10 years of education, PMIS scores of five or less had a sensitivity of 97.8% (95% CI = 93.6-100.0%) and specificity of 99.2% (95% CI = 97.6-100.0%). The PMIS had better specificity than the Mini-Mental State Examination in detecting dementia, especially in older adults with low education. CONCLUSION: The PMIS is a brief and reliable screen for dementia in elderly populations with variable literacy rates.