Intuitively that seems to make sense, but how does that account for almost every first world country except the US? In countries like Canada, the UK, etc. heal

Intuitively that seems to make sense, but how does that account for almost every first world country except the US? In countries like Canada, the UK, etc. healthcare costs don't seem to be nearly as out of control as they are in the US, yet I would expect that patients in countries with socialized health insurance (like Canada), or socialized health care (like the UK) would be even farther removed from the actual cost of healthcare than their US counterparts. Why are their healthcare costs not dramatically more out of control than costs in the US?