Increasing supply is increasing short term demand, while decreasing long term demand. If you can make it so that people are able to get regular care for well visits, checkups, and attention to relatively minor concerns (increasing supply and demand), you reduce the incidence of more severe health concerns by catching things early (reducing crisis demand).

The former would need to include not only lots of GPs, but also the cultural ability to take time off work for doctor’s visits, and childcare, and transportation.