Life expectancy is not entirely medical and is not a particularly good way to compare countries. Consider that among the top causes of death in the US are "accidents" (predominantly motor vehicles) and suicide, both of which are anomalously high in the US.
Consider also that if you go to the top US cause of death (heart disease, clearly medical) and then compare the world rankings for heart disease deaths, you'll find many of the countries that beat the US in the life expectancy rankings do worse than the US in the heart disease mortality rankings.
You'll tend to see similar effects for other medical issues, particularly cancer, in which the US notoriously outperforms many of the European countries that outrank it on life expectancy.