Australia

Its fair to say its skewed.

The point is, comparisons are useful, but the comparisons that are most valuable are from countries (medical systems) estimated to be around the same level of development, and have a similar societal structure.

Good additions might be NZ, Japan, S.Korea, and Canada. (I'm sure theres others)

A better way to do this would be to take apart the US by State, afterall some US states have as large, or larger, populations than the countries listed. This would help account for the wide variability in State to State care. I suppose the reason they didn't is Federal influence is still large, even in the US, also the infographic would become unwieldy with 50 added lines.

The infographic format is probably too simple for the kind of information its trying to communicate.

A better way, from a US centric perspective, might be to use some sort of vine with bunches of States and comparable countries by their side in their appropriate bunch. Say, and i'm just guessing here, Vermont in a bunch that includes Switzerland, while Mississippi might be in a bunch that includes countries with less successful health outcomes.