Only Countries with Socialized Medicine have AAA Bond ratings.
Another thought: the relationship may, in fact, be mostly indirect. Viz., countries with socialized medicine are putting people before profits, and that sort of ethos also gets reflected in the government being financially prudent, and also not allowing corporations to run amok and shirk their fair share of the taxation burden.
A question: How does the extra financing charge related to losing a AAA credit rating relate to the extra hit that a median taxpayer will end up paying? (E.g., if a median taxpayer ends up paying $500/yr in their share of increased national interest on the debt, due to not having socialized medicine, than that $500 could be considered an indirect healthcare cost.)
* I’m not sure that the claim is true – the evidence is just links to wikipedia pages, and not all have them.