LASI-DAD study: a protocol for a prospective cohort study of late-life cognition and dementia in India

Abstract

IntroductionAlzheimer’s disease and related dementias can be considered the epidemic of the 21st century. Particularly, the predicted growth in the size of elderly populations in low-income and middle-income countries is expected to produce a dramatic surge in dementia prevalence and incidence. Although a rising burden of dementia presents an urgent challenge for India, previous efforts to study dementia in the country have relied on non-representative samples in geographically restricted regions. The Harmonised Diagnostic Assessment of Dementia for the Longitudinal Aging Study in India (LASI-DAD) will provide rich, population-representative data on late-life cognition and dementia and their risk factors for the first time in India.MethodsThe LASI-DAD will recruit a sample of 3000 people aged 60+ years. Their family members or friends, whom respondents nominate as informants, participate in the computer-assisted personal interview. The study sample is drawn from the ongoing, nationally representative Longitudinal Aging Study in India, a multipurpose panel survey of aging. We aim to collect rich data on cognitive and neuropsychological tests, informant reports, and epidemiological data through a comprehensive geriatric assessment, and venous blood collection and assays. For a subsample, we collect neuroimaging data. Data collection is currently in progress in 14 States and Union Territories of India. Clinicians will provide clinical consensus diagnosis based on the Clinical Dementia Rating.Ethics and disseminationEthics approval was obtained from the Indian Council of Medical Research and all collaborating institutions. Anonymised data will be available for the larger research community through a secured website hosted by the Gateway to Global Aging Data platform. Research findings from the LASI-DAD team will be disseminated through journal publications and presentations at professional conferences.

The power of knowledge about dementia in Latin America across health professionals working on aging

“…Two main resources for expert knowledge, diagnostic manuals and data‐sharing platforms, were highly appraised by most survey participants, with higher PPKI, younger age, and LAC‐South showing greatest interest in such resources. Harmonized approaches with manuals 17 and registries 9 have proven successful, 22 with some emergent inclusion of LACs 24 . Similarly, data‐sharing platforms such as ADNI, 18,19 DIAN, 23 and GAAIN 41 are beginning to include a small amount of LAC data.…”

“…Although limited in the region, 7–9 accessibility and transmission of public policies are critical components of expert knowledge 10,11 . Knowledge transmission can also address social barriers such as stigma, 12–17 and can be instrumentalized to enhance clinical care and treatment via the use of diagnostic manuals and data‐sharing platforms 9,18–24 . The use of innovative knowledge, such as behavioral insights (BIs), are recent tools for health systems in general, 25–28 and in the aging and dementia fields in particular 29–32 .…”

“…Practical tools to disseminate expert knowledge, such as manuals 9,17 providing guidelines and orientation for dementia diagnosis, as well as data‐sharing platforms (Alzheimer's Disease Neuroimaging Initiative, ADNI; Dominantly Inherited Alzheimer Network, DIAN; The Global Alzheimer's Association Interactive Network, GAAIN) 18–23 that promote research capabilities, are valued instruments. However, the use of these tools at a regional level is restricted in LACs 24 . Most international registries for dementia do not include LACs 9 .…”

The Association of Cognitive and Visual Function in a Nationally Representative Study of Older Adults in India

“…Participants were recruited into LASI-DAD through a stratified random sampling process that ensured an approximately equivalent number of participants at high and low risk of cognitive impairment based on results of cognitive test results in LASI. The LASI-DAD study protocol has been described in detail elsewhere [18, 19].…”

“…Cognitive function was measured using a summary total cognition variable, as well as domain-specific summary variables. The total cognition variable was developed to assess overall cognitive function and has been described previously [19]. A variant of this total cognition variable was constructed for this study that omitted cognitive tests that were largely dependent on vision.…”