No, you can’t just compare it with life expectancy, obviously.
I could set up a fantastic hospital with the best world class equipment and cream of the crop doctors in a war zone (if I paid the doctors enough). The life expectancy of the patients would still be significantly lower than a much lower quality health service in another country where people weren’t having limbs blown off daily or being hit by shrapnel.
In some countries people have healthier lifestyles, diets. It’s very difficult to compare but you cannot compare based on just life expectancy, or PPP cost, obviously, because that is really just a reflection of different currency values and salary levels primarily (as salaries make up far more of the cost of healthcare than equipment or facilities).
To reach a sensible comparison you have to do a detailed comparison between survival rates for different conditions, treatment times, quality of patient care, and then compare this against cost. Obviously there’s subjectivity in which ones you weight as more important but primarily the focus of robust comparisons is mainly looking at survival rates/ recovery rates and patient outcomes per condition plus timely treatment and then looking at a ratio of this against percentage of GDP spent on healthcare to ascertain value for money.
The NHS scores extremely low on such measures, despite variation in how they are calculated, given that this is a developed country, it takes MONTHS or sometimes years for people to receive treatment when in most developed countries this happens in days or weeks for serious conditions, our patient care and outcomes are far lower, cancer survival rates are lower, outcomes for most serious diseases are lower, maternity care and infant mortality are far worse than in comparable countries, etc. And yet our system is not costing us a much lower percentage of GDP than most other comparator countries at our level of development. It’s perfectly clear that our system is useless.
It always used to make me laugh when - before Brexit and they were made to feel so unwelcome that most went home for good - without exception my lovely friends here from the EU used to go back to their own countries whenever they needed medical care or even dentistry because they knew they could book two weeks of holiday, go to see family, fix their medical/ dental issues to a much higher standard than would happen here even if they waited for a year, then come home again. And yet people were constantly going on about “health tourism”. You’d have to have a death wish to come to the UK on purpose to get health treatment.