I'll admit that I had a knee jerk reaction to a compelling correlation, so, like LDAHL, I looked around a little and found this analysis by the NHI https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4112220/
Although the analysis concludes that there are multiple reasons for the the disparity, I agree with Medical Daily that "A higher life expectancy is associated with higher quality of life and better healthcare."
So whether it's the healthcare system, severe comorbidities, high rates of gun violence because we have do darn many of them, the fact is that we have to wonder why our quality of life, as measured by a low life expectancy compared with other developed nations, could stand some improvement.