I’m always weary of these type of comparisons because the basis of country-to-country comparison usually are on a metric that might not be the best indicator of underlying demographic differences. In this case similarities in GDP/capita doesn’t cover differences in historical diets, median age, number of elderly, etc.

Having said that, I suspect that the great disparity of income in the US has something to do with why the death rate from treatable diseases is higher here than in some other countries, as poorer people here not only have less access to state of the art medicine but also live less healthy lifestyles.