Indeed, and as nanavippayutta commented, the implications would be complex.
But I would like to step back and ask: why is health care considered part of economics at all? Should we not be caring for each other as a moral duty?
It’s important to continually question the assumptions of “economic rationalism”. The only reason we see these things in economic terms is because that’s how we have built our world. There’s nothing stopping us from building it differently.
Much, possibly most, medical and health care happens outside the economic realm, even today. People take care of themselves, or look after friends and family, with no economic motive. Within the medical profession, a large proportion of the economic transactions are already placed within the public sphere as Medicare and the like, showing that we, as a human culture, do not want such decisions to be solely based on money.
If medical care is seen as a moral duty, it becomes immediately obvious that we are looking at the wrong things. Most of the major advances in human health over the past years have come from lo-tech things like nutrition, vaccines, hygiene, pre- and post-natal care, better diagnosis, clean water, sewerage, health education, women’s empowerment, giving up smoking, and so on.
Trillions of dollars have been spent on high-end medical research that has had very fitful results. Some things have improved greatly, while others have hardly changed.
If we are serious about medicine as being the promotion of human health, our efforts would be directed to eliminating malaria, legalizing drugs, feeding the hungry, and getting basic amenities to the many still in need. But research dollars are overwhelmingly spent by the rich for the rich.
So yes, in a shrunken economy there would be less money available for advanced medical research, and some people would suffer and die because of that. But shifting medicine out from under the umbrella of economics and Big Pharma would, I believe, save many more lives in simple and unspectacular ways.
The real reason we spend our health money the way we do is not because it is economically rational, but because we value the lives of rich white people more than poor brown people.