What is this study?
SANSCOG study is a first-of-its-kind research project in India and one of the largest, longitudinal studies in the world conducted on the rural, aging population. This is a prospective, community-based, cohort study on healthy, aging individuals, 45 years and above (projected n = 10,000) hailing from the villages of Srinivaspura taluk (sub-district) located in Kolar district in the southern state of Karnataka, India. The study aims to identify risk and protective factors associated with cognitive changes due to normal ageing, dementia and other related disorders. This understanding will, in turn, help develop interventions to prevent or delay the onset of dementia, and therefore, improve quality of life of the elderly.
Why is this study important to India and the world?
For India, this is a very important study, as dementia including Alzheimer’s disease will be one of the major burdens that will affect the elderly and emerge as a major socio- economic challenge in the coming decades. India’s older population (60 years and above) is projected to be 19.1% of the nation’s population, that is, around 316 million, in the year 2050 and therefore, would be one of the leading contributors to dementia cases in the world.
India is unique in terms of genetic susceptibility, diversity in language, education and socio-economic backgrounds, risk factors – diabetes, hypertension, hypercholesterolemia, midlife obesity, smoking and the rapidly changing socio-cultural milieu wherein the joint family system is changing to nuclear families resulting in differential cognitive engagement. Therefore, the risk and protective factors of dementia could be different from what is known so far from studies conducted in Western countries.
Till date, there are no definitive or curative treatments for dementia anywhere in the world. However, previous research has established beyond doubt that the changes in the brain that eventually lead to dementia start at least two decades before the presentation of overt clinical symptoms. In this scenario, early identification of risk factors for dementia and translating this knowledge into preventive strategies would be key in addressing this massive public health concern.
How is this study carried out?
This study follows a multimodal approach that includes detailed clinical, neurocognitive, biochemical, genetic and neuroimaging assessments, with long-term follow up (minimum of 10 years). Thus, this study brings together experts from various disciplines – basic scientists, geneticists, clinicians, cognitive psychologists, social workers, etc., thus leveraging diverse perspectives and comprehensive skill sets. The study is a collaborative work of the Centre for Brain Research, Indian Institute of Science with the National Institute of Mental Health and Neurosciences (NIMHANS), Bangalore and Sri Devaraj Urs Academy of Higher Education (SDUAHER), Kolar.
Unique recruitment and cohort engagement strategies in a rural Indian setting
Carrying out a large-scale research project involving human subjects in a rural setting in India comes with many challenges. So, this study has adopted unique recruitment and cohort engagement strategies to overcome these challenges. Prior to recruitment of participants, the SANSCOG study team liaises with the local public health officials and work closely with the grassroot level leaders and community health workers, to build better connections with the community and to create awareness about our study.
The study team’s field data collectors (FDCs), who are our first point-of contact with our participants, maintains periodic contact with participants through telephone or in-person house visits at least twice a year. We also actively engage the cohort through activities like general health awareness camps, street plays and sports events, during which participants are provided food. Though we don’t offer any treatment, the clinical team provides brief feedback on participants’ blood test reports, clinical tests, ECG and MRI, and makes appropriate referrals to the primary healthcare service, if necessary.
Recruited participants undergo detailed assessments that are done following a three-visit protocol. The first visit happens at the participant’s home, during which socio-demographic data and written consent to participate in the study is obtained. The second visit is at the project site office in Srinivaspura or in a mobile unit, where detailed clinical and neurocognitive assessments are done. Biochemical and genetic tests are done through periodic blood collection camps at the villages due to logistic reasons. The third visit involves neuroimaging, where a subset of the cohort undergoes brain MRI at the Indian Institute of Science (IISc) or National Institute of Mental Health and Neurosciences (NIMHANS) in Bangalore.