How does she conclude this? And what are “social” determinants of health? Wealth? Wealth inequalities are indeed so high in the US and wealth is a major factor for life expectancy (if not the main one?). The average American is 2x richer than the average Italian but the median Italian is 1.5x richer than the median American:
The above is independent of universal health coverage.
Looking at the example of Lexington County, S.C. vs Placer County, Calif.: if we adjust for individual behaviors, is there still a difference in life expectancy? For instance:
People walk more in CA than in SC:
SC is also significantly below the US average in terms of exercise, whereas CA is way above:

What about diet? South Carolinians eat way more red meat:
California is the top producer of organic food, so it’s way more available there:
I don’t say that organic food is necessarily healthier, but it reflects that Californians are way more health-conscious. You can see this in their extremely low smoking prevalence as well:
Californians drink wine, Carolinians drink beer:
The list goes on…
Similar differences exist between countries. So, do we have data at the global or national level explaining the contribution of different factors to life expectancy? Like diet (calories per day? organic %? % of processed food?), exercise (steps per day, exercise per week, sedentary %), wealth (average wealth/capita, median wealth/capita), medical environment (doctors/capita, hospitals/capita, etc.), health consciousness (like a questionnaire “How much do you care about your health?”, or the number of doctor consultations per capita per year), and then “universal healthcare coverage” (but is it just 0 or 1? How do you measure it? If the coverage is universal but provided by the private sector for instance?).
Of course, the US has the worst healthcare system in the (developed) world, and the Swiss one is among the best. I just said that in terms of concept (quasi-mandatory private healthcare coverage, 7.9% uninsured in the US as of 2023, 1.5–3% in Switzerland) they’re not that different since Obamacare. But the devil is in the details, and the way it’s implemented in the US is terrible.