We are please to announce that the newest version of the Harmonized LASI-DAD data files and raw study data are now available at the Gateway to Global Aging Data Website. These newly released data files include both Wave 1 and Wave 2 data. Here we highlight new additions to these data files and where to access the data and accompanying documentation.

The Harmonized Diagnostic Assessment of Dementia for the Longitudinal Aging Study in India (LASI-DAD) is an in-depth study of late-life cognition and dementia, drawing on a subsample of the Longitudinal Aging Study in India (LASI). LASI is a nationally representative survey of the health, economic status, and social well-being of the Indian population aged 45 and older. Its large sample of 73,000+ adults represent not only the country as a whole but also every state. To study late-life cognition and dementia in LASI-DAD, we recruited a sub-sample of 4,000+ LASI respondents aged 60 and older from 18 states and union territories across the country in Wave 1, expanding to 22 states in Wave 2. We administered in-depth cognitive tests and interviewed a family member or friend, who study participants nominated as informants. We carefully selected a set of cognitive tests to enable international comparisons with other dementia studies around the world, including the U.S. HRS-HCAP (Harmonized Cognitive Assessment Protocol) and prior studies in India. More details on the study background and protocol can be found at the study website.

The newest version of the LASI-DAD data includes 4,096 respondents from Wave 1 and 4,638 respondents from Wave 2. Of the 4,638 Wave 2 respondents, 2,566 are follow-up participants from Wave 1, and 2,072 are newly recruited age-eligible respondents, with recruitment following the same sample strategy as Wave 1.

A new hearing measurement was also added in Wave 2 using a hearX device. Variables based on this hearing test, including a hearing screen, pure total average (PTA), and hearing thresholds are included in this data release.

Lastly, data from the collection and assay of venous blood specimens (VBS) is now available for two waves of data collection in the harmonized data files. Samples collected were shipped to the Metropolis laboratory in Delhi for processing. Assays completed included whole blood-based assays, serum-based tests, lipid profile, metabolic panel, thyroid function test, and liver function tests.

The Harmonized LASI-DAD is an excellent and user-friendly dataset for conducting cross-country analysis, and we hope this new update contains useful information to add to your research.

The data files and documentation are available at the Gateway to Global Aging Data Website. The design and methodology of LASI-DAD Wave 2 has been published in the Journal of the American Geriatrics Society. Learn more about the protocol and differences between waves of data collection here.