A global epidemiology of cognitive impairment and dementia due to Alzheimer's disease and related disorders: the COSMIC Collaboration - The Cohort Studies of Memory in an International Consortium (COSMIC) is perfectly positioned to achieve the goals of “evidence-based practice for dementia risk reduction”, “early and appropriate diagnosis”, “research and innovation” and “transnational equity” endorsed by the World Health Assembly’s Global Action Plan on the public health response to dementia, 2017-2025. COSMIC brings together multiple well-characterized population-based longitudinal cohort studies of cognitive aging and dementia from around the world to address the analytical epidemiology of dementia and pre-dementia syndromes, using harmonized data to conduct pooled analyses and individual participant data meta-analyses. Since its initial funding by the NIA/NIH in Sep 2017, COSMIC’s membership has grown to 54 studies from 39 nations, including 35 studies from low- and middle- income countries (LMIC), with an additional 25 in negotiation, and a combined sample size of 175,199 (85,186 White and 90,013 non-White - 39,610 Asian, 15,476 Black, 34,832 Hispanic, 96 other), expected to grow to 300,000. A large international community of researchers has thus been enabled to collaboratively investigate the global epidemiology of mild cognitive impairment (MCI) and dementia. In the next five years, the power of this unique consortium will be harnessed to map the 12 modifiable risk factors of dementia identified by the 2020 Lancet Commission. Some novel risk and resilience factors will be studied in-depth, the built and economic environments, air pollution, social health, and frailty. The incidence of MCI and dementia will be determined in diverse regions and risk models for dementia in specific populations developed. COSMIC will examine the role of cerebrovascular disease by harmonizing neuroimaging biomarkers. It will study the predictive utility of genetic markers in non-European populations. It will investigate the diagnostic and disease-monitoring potential of plasma biomarkers for Alzheimer’s disease in diverse populations. COSMIC is forging new collaborations. It is collaborating with the Davos Alzheimer’s Collaborative (DAC) to develop digital, genetic, and fluid biomarker-based dementia phenotypes in under-represented populations. In collaboration with Dementias Platform UK (DPUK), COSMIC is developing the Dementias Platform Australia (DPAU) for sharing participant level data from COSMIC studies with researchers world-wide. With DPUK and the Alzheimer’s Disease Data Initiative (ADDI), it is developing an ontology for the curation and harmonization of dementia related variables for international data-sharing. In collaboration with the Institute of Health Metrics and Evaluation, COSMIC will document the global burden of risk factors for dementia. In collaboration with the DAC, DPUK, ADDI and the Global Brain Health Institute (GBHI), it is developing a training and education program to increase research capacity in LMICs. With its collaborative approach, data sharing, and global network, COSMIC is creating a demonstrably global epidemiology of dementia that is needed to meet the ambitious goals of the 2017 World Health Assembly and the hopes of people at risk of dementia everywhere.
