Project Summary/Abstract: In this application, we are seeking supplemental funding for Wave 2 activities of the Longitudinal Aging Study in India (LASI). This application builds upon LASI and its allied study, LASI-DAD, a nationally representative survey focused on late-life cognition and dementia in India. The main LASI survey provides socioeconomic and other behavioral data for LASI-DAD respondents, which are not collected as part of the LASI-DAD survey. This information is essential to achieve the aims of the parent LASI-DAD grant, specifically related to assessing cognitive changes over time, understanding their correlates, and estimating the economic and caregiving burdens of dementia. This application seeks funding for the efforts by the HSPH and USC teams to help International Institute for Population Sciences with for the implementation of the follow-up interviews of Wave 1 LASI respondents (N~74,000) as well as newly age-eligible respondents within the sampled households in 36 states and union territories of India. Specifically, this application aims to conduct the following: 1) updating and programming the Wave 2 instrument, including the addition of a new COVID-19 module and capturing socioeconomic changes during the unplanned 4-year delay of LASI Wave 2; 2) conducting pretests and refining the research instrument; 3) tracking the sample; 4) training trainers and field investigators; 5) implementing real-time data monitoring and quality control measures; and 6) obtaining ethical clearance for future genomics studies. Dr. David Bloom and Dr. Jinkook Lee will lead the investigative team for LASI Wave 2 at HSPH and USC respectively. These activities are critical for ensuring quality assurance and harmonization of the LASI survey with the Health and Retirement Study and its international network of surveys.