Variations in the prevalence of MS are at least partly due to sociodemographic, health system, and neurology-specific factors, according to a study published in Neurology. Soonmyung Hwang, MD-candidate, and colleagues conducted an ecological study to examine the associations between age- and sex-adjusted MS prevalence and prespecified sociodemographic, health system, neurologyspecific, and lifestyle factors. At the national level, univariable regression analyses showed significant associations for all investigated factors, apart from obesity prevalence and tobacco use. There was a significant association seen for latitude with MS prevalence in all world regions, while in five of six world regions, there was a significant association seen for the universal health coverage index. In high income countries, significant associations were observed for MS prevalence with all factors except lifestyle factors and MRI unit density, with no associations seen in low-income countries. For all income strata, except low-income countries, latitude was associated with MS prevalence. Current health expenditure per capita and latitude remained significantly associated with MS prevalence in a multivariable analysis.