Original article: https://www.neurology.org/doi/10.1212/WNL.0000000000214226

They note that data from 2020 was excluded due to covid disruptions. They address the limitations of self-reported data in the discussion section at the end - and actually, the fact that the rates vary significantly depending on age, race, and income suggest that there is something going on here. In other words, the "actual" rates of cognitive disability, if you could measure them in a more objective, non self-reported way, might be different from what they found. But even so, the dependency of the rates on age, race, and income might be real.