Dementia risk factors vary across countries depending on social determinants

From my point of view, this study by Nichols et al. is a well-designed and methodologically robust study. One of its main strengths is the use of harmonized data from more than 200,000 participants across 14 countries and regions, allowing comparisons between populations with different socioeconomic and cultural backgrounds thereby strengthening the findings. Although the overall findings are not unexpected, the study makes an important contribution showing that, although the prevalence of individual dementia risk factors varies across countries, common patterns of risk factor clustering are observed regardless of differences in socioeconomic and healthcare contexts. These findings strengthen the evidence that prevention strategies should be adapted to the characteristics and needs of each country. For example, improving access to education may have a greater impact in low- and middle-income countries, whereas interventions targeting obesity, hypertension, and other cardiovascular risk factors may be more relevant in many high-income countries. At the same time, the fact that multiple risk factors tend to occur together across countries supports the development of prevention strategies that address several risk factors simultaneously while being tailored to the needs of each population. Nevertheless, one limitation is that the study focuses on the prevalence and clustering of dementia risk factors rather than evaluating their direct impact on dementia incidence or prevalence in each country. Including such analyses would have provided a better understanding of whether differences in risk factor distribution translate into differences in the burden of dementia. Despite this limitation, the study provides valuable evidence that can help guide public health policies and the development of context-specific dementia prevention strategies.