Seems really hard to peg any one factor as "the cause". How did you land on runaway medical costs?
the money involved in healthcare does bring up some interesting thoughts.
i remember hearing that the "war on poverty" didnt impact poverty rates because govt guidlines dont factor in gov't social services such as $ amount of medicaid recieved, food stamps, etc.
so really the cause of death should include poverty + depending on X govt services, not either or