What factors other than healthcare affect population health

What factors other than healthcare affect population health
The United States spends far more on healthcare than other wealthy industrialized countries but, according to health indicators, fares worse than most of them. On average, other wealthy countries spend about half as much per person on health than the US spends.
Look at life expectancy graphs comparing other countries, you can find graphs at Peterson-KFF Health System Tracker. Also look at graph of Health consumption expenditures per capita, US dollars, PPP adjusted 2017.
After comparing charts answer the following questions.
1. Why is spending so much more than other countries on healthcare a problem?
2. What can Americans( individually or collectively) not buy due to high spending on healthcare?
3. What factors other than healthcare affect population health?
4. Does the evidence suggest that the American healthcare system is not efficient?