Methodological innovations in studying marginalized populations in research on neurodegeneration and ageing

Underrepresented populations, often characterized by minority ethnicity, sex/gender or low socioeconomic status, have a higher risk burden and more adverse lifetime experiences of conditions negatively impacting cognitive health than better represented populations. There are several methodological challenges of research in and with marginalized populations that hinder research on improvements to their cognitive health. This review aims at presenting challenges of recruitment, data collection, and statistical analysis, and points to innovative methods for alleviating these challenges. Careful recruitment and data collection can ensure that marginalized populations are sufficiently represented in research. Multiple factors, including the clinical presentation of symptoms, accelerated biological ageing, and early life adversity need to be incorporated into statistical analysis. Innovative methodologies in research on neurodegeneration and ageing can improve the accuracy of descriptive, predictive and causal investigations, and at least partially address data inequity. These methods can contribute to the aims of reducing inequities in the distribution of healthcare and social care resources.