you're looking for social reproduction theory. services are the portion of socially necessary, reproductive labor. as women have entered the workforce, much of this labor (the non-medical part) can no longer be borne by unpaid laborers who depend on a man to bring home adequate wages to keep them all alive. much of it is still silently borne, invisible and unpaid labor. but now you can go buy your cup of coffee from baristas at Starbucks or whatever, or order food and have it brought to you through the gig economy. medical work has always required too much specialized training to be done entirely at home but it still fits under this umbrella - it was just commoditized faster than the rest. as with all commoditization it took an initial period of enclosure - I recommend reading Federici's Caliban and the Witch for the gory details and the development of this theory.

Value is equivalent to socially necessary labor time. Healthcare labor requires this amount of time. The only odd thing about it is the human to human element, in large part, service labor is produced on demand and consumed at the same time. The fact that it's wage labor means that it's still largely a commodity though.

Unsure if this is what you're asking for but here I go with an overly simplistic attempt. Start by breaking down a specific healthcare need such as "treating a broken finger". Record the number of hours it takes to diagnose, treat, followup, etc. Calculate the dollar cost (or appropriate currency) as best as you can; cost of expendables used, wages of medical workers, and other more concrete dollar valued things. If possible or necessary add some fraction of the less concrete dollar valued things by working out some calculations for the cost of running a medical facility, training/education of medical professionals, retirement, retention efforts and other administrative things.

Do some more math and that should get an approximation, in currency, of the value of a healthcare service.

If you're asking about how things like healthcare relate to things like a factory worker making widgets, maybe think of it like a technician who is called in to repair or maintain a machine in the factory (a bit dehumanizing of an example but their purpose is the same in a way). When the machinery is fixed/maintained, the factory can maintain productivity or increase productivity. When the workers are kept in good health and their injuries are properly treated, the factory can maintain productivity.