Harmonized Diagnostic Assessment of Dementia (DAD) for Longitudinal Aging Surveys in India (LASI)

Project Summary The Harmonized Diagnostic Assessment of Dementia for the Longitudinal Aging Study in India (LASI-DAD) is the first and only nationally representative and publicly available dataset on late-life cognition and dementia in India. Our overarching goals are to develop a first rate, longitudinal study of late-life cognition and dementia in India and to provide rich, high-quality data to the larger research community to advance our understanding of risk factors of late-life cognitive decline and dementia. Further, we administer the Harmonized Cognitive Assessment Protocol (HCAP), a common set of cognitive test batteries used by an international network of researchers, enabling new and innovative comparative studies across both low- and high-income countries. In this application, we aim to prepare for and collect Wave 2 of LASI-DAD. We will conduct follow up interviews at Wave 2 with all Wave 1 respondents and also recruit newly age-eligible respondents. Using Wave 2 data, we aim to estimate the dementia incidence rate at the population level and to investigate its predictors. We also aim to study cognitive changes and their correlates over the 4-year time period and to estimate the economic and caregiving burden of dementia. LASI-DAD provides an unprecedented opportunity to study key modifiable and non-modifiable risk factors for dementia and late-life cognitive decline. Rich, harmonized data on cognitive tests and informant reports, as well as venous blood assays and geriatric clinical assessments, enable cross-country comparisons of the influence of sociodemographic and biological variables (e.g. cardiovascular, metabolic, and inflammatory factors) on late-life cognition and dementia. For Wave 2, we will further innovate by: (1) expanding our venous blood assays to include total and phosphorylated tau protein in serum; (2) improving the measurement of personal exposure to PM2.5 using mobile sensors and identifying the relative contributions of different air pollution emission sources; (3) improving the hearing test protocol using an Android-based audiometry test; (4) assessing ocular health, including the use of retinal fundus photography; and (5) assessing caregiving burden. Altogether, the findings of the proposed investigation will yield new insights on the risk factors for dementia incidence and cognitive decline, allowing a better understanding of potential targets for dementia prevention in India and other countries around the world. As with Wave 1, we will prepare public use data and a codebook in a timely manner and promote data usage through exhibits, training webinars, and a user help desk, actively building a user base of researchers from across multiple scientific disciplines.