UK life expectancy expanded - in line with the OECD average (more or less, there was a little catch up) until recently where (like in a few countries) it seems to be flattening. This is a blunt but well understood measure of a population’s health.
A similar type of trend can be seen in childhood mortality. Although experts can gripe with the data, the overall trend is likely robust. There is also some catch up from OECD average from a poorer start.
This is a good achievement by the UK given what the UK has spent on healthcare since the 1970s.
My general observation here is that the UK has underspend / invested less in healthcare but has managed to obtain an average to above average results.
The under spend as % GDP has been 2 to 4 percent points lower than OECD peers on average. This has been going on since the 1970s. (The World bank data is from 2000, sourced from WHO)
There are many factors that combine to impact life expectnacy and health. Correlation is not causation.
However, I think there is enough data and evidence to suggest that given the amount the UK has invested in health (and social care and education) that if the UK wants to continue the positive trends in health, it will likely have to spend more or at current levels of spend the health out comes will - in my view - likely to continue to tail off.
In this sense, the UK’s NHS has been a unique system that has enabled outsized gains in health outcomes for the amount of spend over the last 50 years.
OECD data.
I can’t make a nice graph widget, but I can show how this % spend on GDP goes back to the 1970s. so this is arguably about 50 years of under spend, at even the lower end of 2% of GDP that’s somewhere in the region of £500bn to £1,000 bn (yes 1 £trillion) in culmulative under spend compared to what would have been spent on the OECD average %.
(Now whether it would have been well spent or what else the UK spent the money on is another debate - maybe the OECD over spent given its outcomes… but given the UK is uniquely low (though Italy is close in some years and has slightly worse outcomes broadly) .
You can see how Germany is approx matching the UK since 1970 on life expectancy and trend (OK it did slowly gain beofre mathcing), but was spending much more of GDP to achieve that.